About This Manual - Spartan Controls

About This Manual - Spartan Controls
About This Manual
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MDS ON THE INTERNET
For information on MDS products, technical support and publication updates, connect to our
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175 Science Parkway, Rochester, N.Y. 14620, U.S.A.
Sales & Customer Support: +1 (716) 242-9600
FAX–All Services: +1 (716) 242-9620
World Wide Web: http://www.microwavedata.com/
MDS 4310
350–512 MHZ
RADIO TRANSCEIVER
INT
ER
FA
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MR
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CD
13.8
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+ DC
–
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Installation, Operation & Field Maintenance
Covering the MDS 4310 Transceiver with the 05-2314Axx PCB,
the MDS 4350 & 4355 Packaged Systems and All Basic Options
MDS 05-2415A01, Rev. A
SEPTEMBER 1994
A CALIFORNIA MICROWAVE DIVISION
MDS 4310 QUICK START GUIDE
Below are the basic steps for installing the MDS 4310 (350—512 MHz) Data Transceiver. The information in parentheses indicates the chapters in this manual where detailed explanations are found.
1. Verify radio set-up parameters. (Chapters 2 & 3)
Check the test data sheets packed with the transceiver to be sure the radio is properly configured
for the intended application. Check especially for these items:
• Proper configuration of software selectable settings such as, CTS delay, soft carrier dekey
(SCD), squelch tail eliminator (STE), time-out timer (TOT) and PTT delay. Chapter 3 gives
instructions for setting these parameters.
• Transmit and Receive frequencies.
(Should be the same as those listed on the station license.)
• Transmitter RF power output.
• Loopback Code.
(Default loopback code consists of the last four digits of the radio’s serial number.)
• Transmit modulation and audio input characteristics.
• Modem speed (if radio is modem-equipped).
2. Securely mount the transceiver. (Chapter 2)
• Use the MDS supplied mounting brackets and four screws or bolts (fasteners not provided).
• Choose a mounting location that allows easy access to the connectors on the end of the radio
and allows an unobstructed view of the LED status indicators.
3. Install and connect the antenna system to the radio. (Chapter 2)
• Use good quality, low loss coaxial cable.
• Keep the antenna feedline as short as possible.
• Avoid sharp bends in the coaxial cable.
• Preset the antenna in the direction of the master station.
• Properly waterproof the antenna connector.
4. Connect and apply DC power to the radio. (Chapter 2)
• Set supply voltage to a nominal 13.8 volts.
• Observe polarity.
• Power cord must be properly fused (3 Amperes).
• Plug in the power plug and tighten the retaining screw.
5. Verify radio communications by observing the LED display. (Chapter 2)
• See Tables 2-2 and 2-3 for interpretation of status LEDs.
• Refine the antenna heading by using a DC voltmeter or Hand-Held Terminal (HHT) to measure
the radio’s received signal (RSSI).
6. Connect the data equipment to the radio INTERFACE connector. (Chapter 2)
• Connection must be made with a DB-25 Male (25 pin) connector.
• Connect only the required pins. Do not use a straight-through RS-232 cable with all pins wired.
• Verify the equipment connected to the INTERFACE connector is configured as DTE. The radio
is configured as DCE (data communications equipment).
• Pin connections for the INTERFACE connector are summarized in Table 2-1.
MDS 2415A01, Rev. A
Front Cover-B
MDS P/N 05-2515A01, Rev. A
SEPTEMBER 1994
MDS 4310
350–512 MHz RADIO TRANSCEIVER
Including the…
MDS 4350 and MDS 4355 PACKAGE MODEL RADIOS
INSTALLATION, OPERATION
AND
FIELD MAINTENANCE
Copyright © 1994
Microwave Data Systems
All Rights Reserved
MICROWAVE DATA SYSTEMS
175 Science Parkway, Rochester, New York 14620
Telephone No.: 716-242-9600, FAX No.: 716-242-9620
The following are trademarks…
Thruline™—Bird, Inc.
HELIAX™—Andrew Corporation.
PCTALK™—The Headlands Press, Inc.
PCPLUS™—DataStorm Technologies, Inc.
PROCOMM™—DataStorm Technologies, Inc.
If further assistance with this product is required, please contact:
MICROWAVE DATA SYSTEMS
A Division of California Microwave Incorporated
175 Science Parkway
Rochester, New York 14620
Telephone No.: 716-242-9600
FAX No.: 716-242-9620
Copyright © 1994 by Microwave Data Systems
All rights reserved.
TABLE OF CONTENTS
CHAPTER 1—GENERAL
INTRODUCTION ------------------------------------------------------------------------------------------------------ 1-1
APPLICATIONS-------------------------------------------------------------------------------------------------------- 1-1
TERMS “ANALOG” AND “DIGITAL” ---------------------------------------------------------------------------- 1-2
MDS 4310 MODULATION TECHNIQUES ----------------------------------------------------------------------- 1-2
MICROCONTROLLER FEATURES ------------------------------------------------------------------------------- 1-2
SOFT CARIER DEKEY ----------------------------------------------------------------------------------------------- 1-3
CONTROL INPUTS AND OUTPUTS ------------------------------------------------------------------------------ 1-3
MODEL NUMBER CODES -------------------------------------------------------------------------- 1-4
MAIN PRINTED CIRCUIT BOARD MODELS -------------------------------------------------- 1-4
SPECIFICATIONS ----------------------------------------------------------------------------------------------------- 1-5
OPTIONAL EQUIPMENT, ACCESSORIES and CERTIFICATIONS -------------------------------------- 1-10
Special Certifications --------------------------------------------------------------------------------- 1-10
1200 BPS Bell 202T Modem ------------------------------------------------------------------------ 1-11
4800 BPS Modem ------------------------------------------------------------------------------------- 1-11
9600 BPS Modem ------------------------------------------------------------------------------------- 1-11
Audio Processing Module---------------------------------------------------------------------------- 1-11
Order Wire Module ----------------------------------------------------------------------------------- 1-11
Remote Maintenance Module (Internal)—P/N 03-1958A01 ----------------------------------- 1-11
Hand-Held Terminal ---------------------------------------------------------------------------------- 1-12
RS-232 to RS-422 Converter Assembly—P/N 01-2358A01------------------------------------ 1-12
TTL to RS-232 Converter Assembly --------------------------------------------------------------- 1-12
CHAPTER 2—INSTALLATION
OVERVIEW -------------------------------------------------------------------------------------------------------------2-1
SURFACE MOUNTING ---------------------------------------------------------------------------------------------- 2-2
EXTERNAL CONNECTIONS --------------------------------------------------------------------------------------- 2-4
ANTENNA Connector --------------------------------------------------------------------------------- 2-4
DC IN (Power) Connector ----------------------------------------------------------------------------- 2-4
INTERFACE Connector ------------------------------------------------------------------------------- 2-4
INTERFACE Connector Pin Functional Descriptions ---------------------------------------------2-7
FRONT PANEL INDICATORS ------------------------------------------------------------------------------------ 2-11
TRANSCEIVER CONFIGURATION JUMPERS --------------------------------------------------------------- 2-12
J14—Receiver Audio Output Phase ---------------------------------------------------------------- 2-13
J16—Full Duplex Option Connector --------------------------------------------------------------- 2-13
MODEMS—GENERAL --------------------------------------------------------------------------------------------- 2-13
Introduction -------------------------------------------------------------------------------------------- 2-13
The Role of the Modem ------------------------------------------------------------------------------ 2-14
RTS and CTS Signals ------------------------------------------------------------------------------- 2-14
DCD Signal -------------------------------------------------------------------------------------------- 2-14
POWER REQUIREMENTS----------------------------------------------------------------------------------------- 2-14
ANTENNAS AND FEEDLINES ----------------------------------------------------------------------------------- 2-15
Antenna Selection and Mounting ------------------------------------------------------------------- 2-15
Feedline Selection------------------------------------------------------------------------------------- 2-16
Feedline Installation ---------------------------------------------------------------------------------- 2-17
MDS 2141A01, Rev. A
i
CHAPTER 3—PROGRAMMING AND DIAGNOSTICS
INTRODUCTION ------------------------------------------------------------------------------------------------------ 3-1
TERMINAL CONNECTION AND STARTUP ------------------------------------------------------------------- 3-1
Opening The Diagnostic Channel -------------------------------------------------------------------- 3-3
CAPABILITIES OF THE HHT -------------------------------------------------------------------------------------- 3-4
Review Operating Parameters and Diagnostic Information -------------------------------------- 3-4
Setting the Operating Parameters--------------------------------------------------------------------- 3-5
Program User Information ---------------------------------------------------------------------------- 3-5
USING THE HAND-HELD TERMINAL -------------------------------------------------------------------------- 3-5
Command Syntax --------------------------------------------------------------------------------------- 3-5
Shift Key ------------------------------------------------------------------------------------------------- 3-5
Backspace (BKSP) Key ------------------------------------------------------------------------------- 3-5
Error Messages------------------------------------------------------------------------------------------ 3-6
Closing the Diagnostic Channel ---------------------------------------------------------------------- 3-6
PROGRAMMING EXAMPLES ------------------------------------------------------------------------------------- 3-6
PROGRAMMING OWNER’S INFORMATION ----------------------------------------------------------------- 3-8
PASSWORD PROTECTION----------------------------------------------------------------------------------------- 3-8
DIAGNOSTIC EVALUATION -------------------------------------------------------------------------------------- 3-8
Test Modes ---------------------------------------------------------------------------------------------- 3-9
EQUIPMENT DIAGNOSTICS DEFINITIONS ------------------------------------------------------------------- 3-9
DIAGNOSTIC EXAMPLES----------------------------------------------------------------------------------------- 3-10
RF Power Output Check ----------------------------------------------------------------------------- 3-10
Received Signal Strength Indication (RSSI) Check ---------------------------------------------- 3-10
PROGRAMMING AND TEST COMMANDS ------------------------------------------------------------------- 3-11
HAND-HELD TERMINAL SETUP DEFAULTS --------------------------------------------------------------- 3-13
HAND-HELD TERMINAL WIRING ----------------------------------------------------------------------------- 3-14
Adapter Plug Wiring ---------------------------------------------------------------------------------- 3-14
HHT ALTERNATIVES ---------------------------------------------------------------------------------------------- 3-15
Cable Wiring for a PC or ASCII Terminal -------------------------------------------------------- 3-15
CHAPTER 4—FIELD TESTS AND ADJUSTMENTS
GENERAL -------------------------------------------------------------------------------------------------------------- 4-1
TEST EQUIPMENT REQUIRED ----------------------------------------------------------------------------------- 4-1
CONSTRUCTING A DATA TERMINAL EMULATOR-------------------------------------------------------- 4-3
REMOTE MAINTENANCE CONSIDERATIONS--------------------------------------------------------------- 4-5
INTRODUCTION TO FIELD TESTS & ADJUSTMENTS ----------------------------------------------------- 4-6
TEST PROCEDURES:
Basic Transceiver Checks ----------------------------------------------------------------------------- 4-7
Transmit Frequency, Squelch, Deviation and Receive Audio Output
For Radios with No Internal Modem----------------------------------------------------- 4-10
For Radios with MDS’s Internal 1200 BPS Modem ----------------------------------- 4-11
For Radios with MDS’s Internal 4800 BPS Modem ----------------------------------- 4-14
For Units with MDS’s Internal 9600 BPS Modem ------------------------------------ 4-16
REMOTE MAINTENANCE MODULE—
Loopback Code Programming, Mode Selection, Calibration & Testing ---------------------- 4-19
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TABLE OF CONTENTS
MDS 2141A01, Rev. A
CHAPTER 5—THEORY OF OPERATION
RECEIVE FRONT END ----------------------------------------------------------------------------------------------- 5-1
HIGH IF ------------------------------------------------------------------------------------------------------------------ 5-1
LOW IF -------------------------------------------------------------------------------------------------------------------5-1
RECEIVE AUDIO ------------------------------------------------------------------------------------------------------ 5-1
SQUELCH --------------------------------------------------------------------------------------------------------------- 5-2
POWER SUPPLY -------------------------------------------------------------------------------------------------------5-2
TRANSMIT POWER AMPLIFIER ---------------------------------------------------------------------------------- 5-3
ANTENNA SWITCH -------------------------------------------------------------------------------------------------- 5-3
DIRECTIONAL COUPLER------------------------------------------------------------------------------------------- 5-3
KEYLINE AND CONTROL CIRCUITS --------------------------------------------------------------------------- 5-3
RADIO DISABLE ------------------------------------------------------------------------------------------------------ 5-3
AUDIO/DATA MODULATION INPUT SWITCHING ---------------------------------------------------------- 5-4
MICROCONTROLLER/EEPROM ---------------------------------------------------------------------------------- 5-4
DIAGNOSTICS DATA CONTROL --------------------------------------------------------------------------------- 5-4
TRANSMIT AUDIO --------------------------------------------------------------------------------------------------- 5-5
PLL/SYNTHESIZER --------------------------------------------------------------------------------------------------- 5-5
RS-232 DATA INTERFACE------------------------------------------------------------------------------------------ 5-5
LED INDICATORS ----------------------------------------------------------------------------------------------------5-5
CHAPTER 6—TROUBLESHOOTING
This section contains basic field troubleshooting assistance for the transceiver system.
APPENDIX A—1200 BPS BELL 202T COMPATIBLE MODEM
INTRODUCTION ----------------------------------------------------------------------------------------------------- A-1
SPECIFICATIONS ---------------------------------------------------------------------------------------------------- A-1
ALIGNMENT ---------------------------------------------------------------------------------------------------------- A-1
THEORY OF OPERATION------------------------------------------------------------------------------------------ A-2
APPENDIX B—4800 BPS FSK MODEM
INTRODUCTION ----------------------------------------------------------------------------------------------------- B-1
SPECIFICATIONS ---------------------------------------------------------------------------------------------------- B-1
INSTALLATION ------------------------------------------------------------------------------------------------------ B-1
ALIGNMENT ---------------------------------------------------------------------------------------------------------- B-1
THEORY OF OPERATION------------------------------------------------------------------------------------------ B-1
APPENDIX C—9600 BPS FSK MODEM
INTRODUCTION ----------------------------------------------------------------------------------------------------- C-1
SPECIFICATIONS ---------------------------------------------------------------------------------------------------- C-1
INSTALLATION ------------------------------------------------------------------------------------------------------ C-1
ALIGNMENT ---------------------------------------------------------------------------------------------------------- C-1
THEORY OF OPERATION------------------------------------------------------------------------------------------ C-1
MDS 2141A01, Rev. A
TABLE OF CONTENTS
iii
APPENDIX D—REMOTE MAINTENANCE MODULE
INTRODUCTION ----------------------------------------------------------------------------------------------------- D-1
OPERATION ---------------------------------------------------------------------------------------------------------- D-1
MODULE ADJUSTMENTS & CALIBRATION ---------------------------------------------------------------- D-2
DETERMINING THE PRESENCE OF A REMOTE MAINTENANCE MODULE ----------------------- D-2
INSTALLATION & REPLACEMENT ---------------------------------------------------------------------------- D-3
TESTING THE LOOPBACK CODE ------------------------------------------------------------------------------ D-4
TROUBLESHOOTING ---------------------------------------------------------------------------------------------- D-4
THEORY OF OPERATION ----------------------------------------------------------------------------------------- D-5
APPENDIX E—ORDER WIRE MODULE
INTRODUCTION ------------------------------------------------------------------------------------------------------ E-1
THEORY OF OPERATION ------------------------------------------------------------------------------------------ E-2
APPENDIX F—MDS 4355 REMOTE RADIO PACKAGED SYSTEM
GENERAL INFORMATION----------------------------------------------------------------------------------------- F-1
INTERFACE ASSEMBLIES ----------------------------------------------------------------------------------------- F-2
Analog Interface Assembly—P/N 03-1105A21 --------------------------------------------------- F-2
RS-232/TTL Digital Interface Assembly—P/N 03-1467A21 ------------------------------------ F-2
POWER CONNECTIONS -------------------------------------------------------------------------------------------- F-3
Primary Power—J3------------------------------------------------------------------------------------- F-3
Power for Accessories --------------------------------------------------------------------------------- F-3
Back-up Battery ---------------------------------------------------------------------------------------- F-3
ANALOG INTERFACE BOARD CONNECTIONS—P/N 03-1105A21, Rev. C ---------------------------- F-4
Audio and Keyline—J1 -------------------------------------------------------------------------------- F-4
Additional Interface Connections -------------------------------------------------------------------- F-4
Audio Alignment --------------------------------------------------------------------------------------- F-5
DIGITAL RS-232/TTL INTERFACE BOARD CONNECTIONS, P/N 03-1467A21 --------------------- F-11
Summary ----------------------------------------------------------------------------------------------- F-11
RS-232 Digital Interface Connections ------------------------------------------------------------- F-12
TTL Digital Interface Connections ---------------------------------------------------------------- F-12
Additional Interface Connections ------------------------------------------------------------------ F-12
Order Wire Audio Alignment ---------------------------------------------------------------------- F-12
APPENDIX G—MDS 4355 REMOTE RADIO PACKAGED SYSTEM
GENERAL INFORMATION---------------------------------------------------------------------------------------- G-1
CUSTOMER MODIFICATION ------------------------------------------------------------------------------------ G-2
MOUNTING ----------------------------------------------------------------------------------------------------------- G-2
INTERFACE ASSEMBLIES—Summary ------------------------------------------------------------------------- G-5
Analog Interface/Utility Assembly—P/N 03-2110A01 ------------------------------------------ G-5
RS-232 Digital Interface and Utility Board—P/N 03-2115A01 -------------------------------- G-5
USING THE MDS HAND-HELD TERMINAL------------------------------------------------------------------ G-5
POWER CONNECTIONS ------------------------------------------------------------------------------------------- G-6
Primary Power—TB2--------------------------------------------------------------------------------- G-6
Power for Accessories -------------------------------------------------------------------------------- G-7
Back-up Battery --------------------------------------------------------------------------------------- G-7
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TABLE OF CONTENTS
MDS 2141A01, Rev. A
ANALOG INTERFACE/UTILITY BOARD CONNECTIONS—P/N 03-2110A01------------------------- G-8
Audio and Keyline—TB1 ----------------------------------------------------------------------------- G-8
Additional Interface Connections -------------------------------------------------------------------- G-8
Audio Alignment--------------------------------------------------------------------------------------- G-9
Order Wire Audio Alignment ------------------------------------------------------------------------ G-9
DIGITAL INTERFACE/UTILITY BOARD CONNECTIONS—P/N 03-2115A01— -------------------- G-13
Summary ---------------------------------------------------------------------------------------------- G-13
RS-232 Digital Interface Connections ------------------------------------------------------------ G-13
Additional Interface Connections ------------------------------------------------------------------ G-14
Order Wire Audio Alignment ---------------------------------------------------------------------- G-14
APPENDIX H—MDS 4310-HL
DATA TRANSCEIVER FOR USE IN HAZARDOUS LOCATIONS
INTRODUCTION ----------------------------------------------------------------------------------------------------- H-1
CONDITIONS OF APPROVAL ------------------------------------------------------------------------------------ H-1
APPENDIX I—CANADIAN CERTIFICATION
RSS APPROVALS ----------------------------------------------------------------------------------------------------- I-1
RESTRICTIONS -------------------------------------------------------------------------------------------------------- I-1
APPENDIX J—AUDIO PROCESSING MODULE
INTRODUCTION ------------------------------------------------------------------------------------------------------ J-1
SPECIFICATIONS ----------------------------------------------------------------------------------------------------- J-1
ALIGNMENT ----------------------------------------------------------------------------------------------------------- J-2
CONFIGURATION ---------------------------------------------------------------------------------------------------- J-2
TABLES
Table 2-1. DB-25 Interface Connector Pin Functions -------------------------------------------------------------- 2-6
Table 2-2. External Indicators For Radios Without Internal Modems ----------------------------------------- 2-11
Table 2-3. External Indicators For Radios WithInternal Modems ---------------------------------------------- 2-12
Table 2-4. J11–External Interface TTL/RS-232 ------------------------------------------------------------------ 2-13
Table 2-5. J14 Receiver Audio Output Normal/Inverted -------------------------------------------------------- 2-13
Table 2-6. Signal Loss versus Cable Length and Type ---------------------------------------------------------- 2-16
Table 3-1. Diagnostic and Control Capabilities ------------------------------------------------------------------- 3-10
Table 3-2. Programming and Test Commands -------------------------------------------------------------------- 3-11
Table 3-3. Hand-Held Terminal Operating Defaults ------------------------------------------------------------- 3-14
Table 4-1. Main Circuit Board Potentiometer Settings for Remote Maintenance------------------------------ 4-6
Table 4-2. Test Procedure Reference Chart ------------------------------------------------------------------------- 4-6
Table B-1. Settings for the MDS 4800 bps Modem’s Configuration Switch S1 ------------------------------ B-3
Table C-1. Settings for the MDS 9600 bps Modem’s Configuration Switch S1 ------------------------------ C-2
Table F-1. Interface Board J1 Connectors ------------------------------------------------------------------------- F-11
Table G-1. Interface Board TB1 Connectors -------------------------------------------------------------------- G-13
Table J-1. P/N 03–2301A01 Configuration Switch Settings ------------------------------------------------------ J-2
MDS 2141A01, Rev. A
TABLE OF CONTENTS
v
ILLUSTRATIONS
Figure 1-1. MDS 4310 Model Number Codes---------------------------------------------------------------------- 1-4
Figure 1-2. Printed Circuit Model Number Location -------------------------------------------------------------- 1-5
Figure 1-3. MDS 4310 Transceiver—Major Assemblies -------------------------------------------------------- 1-13
Figure 2-1. Mounting Dimensions—Front View------------------------------------------------------------------- 2-3
Figure 2-2. Mounting Dimensions—Bottom View ---------------------------------------------------------------- 2-3
Figure 2-3. External Connections------------------------------------------------------------------------------------- 2-5
Figure 2-4. Received Signal Strength Indicator Calibration Chart (Typical)---------------------------------- 2-10
Figure 2-5. Location of Configuration Jumpers ------------------------------------------------------------------- 2-12
Figure 2-6. Detail of Configuration Jumpers—J14 --------------------------------------------------------------- 2-13
Figure 3-1. Hand-Held Terminal Connected to the MDS 4310 Transceiver ----------------------------------- 3-2
Figure 3-2. MDS 4355 Packaged Transceiver ---------------------------------------------------------------------- 3-2
Figure 3-2. Hand-Held Terminal Keypad --------------------------------------------------------------------------- 3-6
Figure 3-3. HHT Initialization Display ----------------------------------------------------------------------------- 3-13
Figure 3-4. DB-25 Interface Adapter Wiring ---------------------------------------------------------------------- 3-14
Figure 3-5. DB-9 to DB-25 Interface Cable Wiring -------------------------------------------------------------- 3-15
Figure 3-6. DB-25 to DB-25 Interface Cable Wiring ------------------------------------------------------------- 3-15
Figure 4-1. Remote Data Terminal Emulator Wiring-------------------------------------------------------------- 4-4
Figure 4-2. Construction Options for Building a Data Terminal Emulator ------------------------------------- 4-4
Figure 4-3. VCO Lock Voltage Test Point -------------------------------------------------------------------------- 4-9
Figure 4-4. 1200 bps AFSK Modem -------------------------------------------------------------------------------- 4-13
Figure 4-5. 4800 BPS FSK Modem --------------------------------------------------------------------------------- 4-15
Figure 4-6. 9600 BPS FSK Modem --------------------------------------------------------------------------------- 4-17
Figure 4-7. Remote Maintenance Module -------------------------------------------------------------------------- 4-19
Figure 4-8. Remote Maintenance Screen --------------------------------------------------------------------------- 4-23
Figure 4-9. MDS 4310 Transceiver PC Board Test Points and Adjustments --------------------------------- 4-25
Figure 5-1. MDS 4310 Transceiver Block Diagram --------------------------------------------------------------- 5-7
Figure A-1. 1200 bps Modem PC Board --------------------------------------------------------------------------- A-1
Figure A-2. Bell 202T Compatible Modem Block Diagram----------------------------------------------------- A-3
Figure B-1. MDS 4800 bps Modem Block Diagram -------------------------------------------------------------- B-2
Figure B-2. MDS 4800 bps Modem Assembly Diagram ---------------------------------------------------------B-3
Figure C-1. MDS 9600 bps Modem Block Diagram -------------------------------------------------------------- C-3
Figure C-2. 9600 bps Modem Assembly Diagram ----------------------------------------------------------------- C-3
Figure D-1. Remote Maintenance Module, P/N 03-1958A01 --------------------------------------------------- D-2
Figure E-1. Order Wire Module -------------------------------------------------------------------------------------- E-1
Figure E-2. Order Wire Board Component Layout ---------------------------------------------------------------- E-2
Figure E-3. Order Wire Block Diagram ----------------------------------------------------------------------------- E-3
Figure F-1. MDS 4350 Interior View -------------------------------------------------------------------------------- F-1
Figure F-2. MDS 4350 Features & Dimensions -------------------------------------------------------------------- F-2
Figure F-3. 03-1105A21 Keying Options, Analog Interface Assembly----------------------------------------- F-6
Figure F-4. MDS 4350 Packaged System Wiring Diagram ------------------------------------------------------ F-7
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TABLE OF CONTENTS
MDS 2141A01, Rev. A
Figure F-5. Analog Interface Assembly 03-1105A21 ------------------------------------------------------------- F-9
Figure F-6. MDS 4350 Packaged System Wiring Diagram
with 03-1467A21 RS-232/TTL Interface ---------------------------------------------------------- F-13
Figure F-7. RS-232/TTL Interface Assembly 03-1467A21 ---------------------------------------------------- F-15
Figure G-1. MDS 4355 Interior (AC Version) with Fiberglass Enclosure Removed ------------------------- G-1
Figure G-2. MDS 4355 Dimensions, Feed-Through Couplings & Mounting Points ------------------------- G-2
Figure G-3. Exploded View of DC Version of System ----------------------------------------------------------- G-3
Figure G-4. Exploded View of AC Version of System ----------------------------------------------------------- G-4
Figure G-5. Plugs for Primary Power TB2 and Interface TB1 Connectors ------------------------------------ G-7
Figure G-6. Keying Options for the 03-2110A01 Analog Interface/Utility PC Board --------------------- G-10
Figure G-7. MDS 4355 Packaged System Wiring Diagram
with the 03-2110A01 Analog Interface/Utility Board ------------------------------------------ G-11
Figure G-8. Analog Interface Assembly 03-2110A01 ---------------------------------------------------------- G-12
Figure G-9. MDS 4355 Packaged System Wiring Diagram ith the
03-2115A01 RS-232 Digital Interface & Utility PCB ------------------------------------------ G-15
Figure G-10. RS-232 Digital Interface and Utility Board ------------------------------------------------------ G-16
Figure J-1. Audio Processing Module Installation Diagram ------------------------------------------------------ J-1
Figure J-3. 03-2301A01 Audio Processing Module ---------------------------------------------------------------- J-2
MDS 2141A01, Rev. A
TABLE OF CONTENTS
vii
About This Manual
This manual covers three models in the MDS 4300 Series of 450 MHz radio transceivers.
The MDS 4310 is the basic transceiver, and it is the main focus of this manual. The MDS
4350 and MDS 4355 are packaged weatherproof models, which include the MDS 4310 radio
plus a power supply, back-up battery and interface/utility board, all mounted in a NEMA 4
enclosure. Appendix F of this manual covers the main features of the MDS 4350 and
Appendix G covers the MDS 4355. All discussions relating only to the MDS 4350 and MDS
4355 Packaged models will be clearly marked.
The following is a brief summary of the contents in each chapter of the manual.
Chapter 1—General, provides a general introduction to the MDS 4310 Transceiver and its
standard and optional equipment. A specifications table provides a detailed summary of the
radio’s electrical and mechanical features.
Chapter 2—Installation, contains steps for installation, hookup and checkout of the MDS
4310 Transceiver. Recommendations are also provided for feedline and antenna selection,
connection to external equipment, jumper configuration settings and other requirements for
planning a successful radio installation.
Chapter 3—Programming and Diagnostics, gives procedures for connecting a Hand-Held
Terminal, or a standard ASCII Terminal to the radio for accessing and controlling the
transceiver’s operating parameters and performing diagnostic checks.
Chapter 4—Field Tests and Alignments, contains detailed procedures for testing and
adjusting the equipment to ensure maximum performance. The procedures here are not
required for normal installations, but can be performed as an aid in diagnosing a suspected
problem, or following replacement or repair of an assembly.
Chapter 5—Theory of Operation, provides an overview of the circuits comprising the
MDS 4310 Transceiver. The text is supported with an oversized block diagram at the end of
the chapter to aid in understanding the material.
Chapter 6—Troubleshooting System Problems, contains recommended evaluation
procedures for system troubles, and suggests possible solutions.
viii
TABLE OF CONTENTS
MDS 2141A01, Rev. A
CHAPTER 1—GENERAL
INTRODUCTION
The MDS 4310 Transceiver offers continuous duty, high-performance data communications
in the 390–470 MHz frequency band. The transceiver is fully synthesized and can be programmed to operate on 12.5 kHz and 25 kHz channels within this range.
The MDS 4310 Transceiver can be supplied with a MDS 2314Axx main PC board or a MDS
2013Axx main PC board. Although the two PC boards are similar, this manual covers
transceivers with the 2314Axx main PC board. Refer to the MDS 05-2141A01 manual for
specific information regarding transceivers equipped with the 2013Axx main PC board.
The Transceiver’s design is highlighted by a compact and rugged die-cast aluminum case
which houses the basic RF unit, and all diagnostic and modem options. The MDS 4350 and
MDS 4355 are alternate weatherproof models which include the MDS 4310 radio plus a
power supply, back-up battery and interface/utility board, all mounted in a NEMA 4X
enclosure. Appendix F of this manual covers the main features of the MDS 4350 and
Appendix G covers the MDS 4355 Package.
The contents of this manual center on the MDS 4310 Data Transceiver. All discussions
relating only to the MDS 4350 and MDS 4355 Packaged models are clearly marked.
TRANSCEIVER
M D S 2 0 0 0 D A T A T R A N S C E IV E R
+
–
The MDS 4310 Data Transceiver
The MDS 4350 Packaged Radio
(MDS 4355 Similar in appearance)
APPLICATIONS
The MDS 4310 Data Transceiver is a single channel, half-duplex, radio designed for use in
multiple address systems (MAS) such as those licensed under Part 90 of the Federal
Communications Commission rules, with an emission designation of F1D, F2D, or F3D,
depending on application and configuration.
Continued on next page.
MDS 05-2415A01, Rev. A
1-1
As a component of point-to-multipoint data telemetry systems, the MDS 4310 Transceiver is
well suited for such applications as:
• Supervisory Control and Data
Acquisition (SCADA)
• Telemetry Systems
• Energy Distribution Automation
•
•
•
•
Information Systems
Oil Fields and Pipelines
Alarm Monitoring
Security
MDS 4000 Series radio systems offer the advantage of a frequency band which in many areas
is specially coordinated to provide protection from co-channel interference. Because these are
primarily data-only channels, voice users are not likely to interfere with data transmission
and reception.
TERMS “ANALOG” AND “DIGITAL”
In all MDS literature, the terms “analog” and “digital” are commonly used to describe the
modulation modes and other signal characteristics of various products. The following are
examples of how these terms are commonly used in this manual.
Analog Modem, Analog Radio, Analog Mode—
These terms relate to equipment or operating modes using linear frequency modulation
and detection techniques. The circuitry handles analog communication signals, such as
audio frequency shift keying (AFSK) or analog voice frequency signals through the
system. Generally, these products or modes operate in the 50 to 1200 bits per second
(bps) data range in non-voice applications. Modulation sources include an internal MDS
brand 1200 bps modem or external 4-wire audio sources such as AFSK modems.
Digital Modem, Digital Radio, Digital Mode—
These terms relate to equipment or operating modes using non-linear frequency shift
keying modulation and detection techniques. The signal may alternate between two or
three discrete frequencies (FSK) depending on equipment configuration. Generally, these
products or modes operate in the 4800 and 9600 bps range.
MDS 4310 MODULATION TECHNIQUES
The MDS 4310 Transceiver can be modulated by either audio frequency shift keying (AFSK)
or frequency shift keying (FSK) controlled directly by the digital output of the MDS internal
modems. Alternatively, an external modem can be used for controlling AFSK transmission.
The MDS 4310 is capable of interfacing with data equipment at standard rates between 50
and 4800 bits per second (bps) with an asynchronous interface to the local terminal unit. The
MDS 4310 provides a synchronous or asynchronous interface at data speeds of 1200, 4800
and 9600 bps with one of the optional FSK modems installed internally.
MICROCONTROLLER FEATURES
The MDS 4310 Transceiver features an internal microcontroller that allows user
programming and control of operating parameters and interrogation of diagnostic data.
Programming of radio settings and monitoring of operating parameters can be done with a
terminal unit connected through the transceiver’s DB-25 INTERFACE connector, eliminating
the need to remove the radio from its mounting position or open its top cover. The terminal
can be either an MDS-supplied Hand-Held Terminal (HHT), or an IBM PC (or compatible)
personal computer running MDS-supplied software, or other PC-based communications
1-2
GENERAL
MDS 05-2415A01, Rev. A
software (such as PCPLUS™, PROCOMM™, PCTALK™, etc.). As a third alternative, any
terminal with an RS-232 serial port can also be used.
With one of these devices connected, the user can program the transmit and receive
frequencies, RTS/CTS delay time, PTT delay, soft carrier dekey, time-out-timer, loopback
code and the MDS-patented Squelch Tail Eliminator circuit. In addition, an internal message
field (up to 27 characters) can be entered to label each transceiver with its own identity.
Password security and several other functions are also programmable.
Diagnostic functions that can be measured through the diagnostic module include received
signal strength indication (RSSI), various critical voltage levels, internal temperature,
forward power, and antenna/feedline VSWR. When equipped with the remote maintenance
module and used in a system with an MDS 4100 Series Master Station, several of these
diagnostic measurements can be sent over-the-air back to the master station for display by the
associated PC diagnostic software.
The internal micro-controller also provides basic indication of operating parameters and
values. While not a substitute for calibrated test equipment, this is useful for quick field
evaluations.
SOFT CARIER DEKEY
This feature can be used to keep the transmitter keyed for a short period of time (typically up
to 5 ms) after the last data bit has been transmitted. This period of silence provides a clear
indication that the message has ended and helps ensure no errors are introduced into the data
stream as a result of the transmitter unkeying too soon. The soft carrier dekey feature can be
selected or modified by using the HHT.
CONTROL INPUTS AND OUTPUTS
Four control inputs and outputs are provided on the MDS 4310 Data Transceiver’s 25-pin
“D” INTERFACE connector. They are:
1. Receiver Squelch. This output goes low when the receiver is squelched, and is
pulled high when the receiver squelch is open. When the squelch is open, this pin
supplies +8 Vdc through a 1 kΩ resistor.
2. Out-of-Lock Alarm. When this output is low (less than 0.5 Vdc), it indicates normal
operation. A logic high (greater than 4 Vdc) indicates a failure in the phase lock loop
signal source, or a transmitter time-out condition.
3. Received Signal Strength Indicator. This analog signal output supplies a received
signal strength indicator (RSSI) voltage on Pin 21 of the DB-25 connector. The RSSI
voltage is proportional to the strength of the signal present at the antenna connector,
and provides a useful indication of signal levels between –120 dBm and –60 dBm.
This can be especially helpful during installation to aid in aiming the station antenna
for maximum received signal strength.
4. Radio Disable. When this input on Pin 12 of the INTERFACE connector senses a
ground, it disables or “turns off” most circuits in the radio, including transmit,
receive, modem and diagnostic functions. This reduces power consumption, yet
preserves the radio’s ability to be brought quickly online. Total current drain in the
disabled state is less than 14 mA.
The annunciator or LED indicator panel on the transceiver’s face shows the radio’s basic
performance without removing the housing cover. For transceivers without a built-in modem,
front-panel indicators are provided for primary power on, receive carrier detect, out-of-lock
MDS 05-2415A01, Rev. A
GENERAL
1-3
alarm, transmit keyline activity and transmit status. When used with the modem option, an
annunciator panel indicates the status of the RS-232 interface lines (TXD, RXD, DCD, RTS,
CTS). If desired, the LED display can be turned off by moving a jumper inside the radio.
This may be desirable in applications where power consumption must be kept to an absolute
minimum.
MODEL NUMBER CODES
The model number as found on the serial number label may be used to determine the general
hardware configuration of the radio as it was shipped from the factory. Figure 1-1 illustrates
the significance of the various characters in the radio’s serial number. The serial number
label is located on the end of the radio enclosure.
OPERATION
INTERFACE
BANDWIDTH
SEPARATION
FREQUENCY RANGE
(R) Base/Remote
(0)
(2)
(A)
(D)
(1) 12.5 KHz
(5) 5–10 MHz/Simplex
(A)
(E)
(F)
(G)
(H)
(I)
4-Wire Audio
1200 BPS
4800 BPS
9600 BPS
390–406 MHz*
450–470 MHz*
406–430 MHz*
350–370 MHz
370–390 MHz
390–410 MHz
(J)
(K)
(L)
(M)
(N)
406–430 MHz
430–450 MHz
450–470 MHz
470–490 MHz
490–512 MHz
* 2013 printed circuit board only
4 3 1 0 R N 1
●
1 5
● ● ● ●
POWER SETTING
DIAGNOSTICS
REGULATORY CERTIFICATION
SAFETY CERTIFICATION
(1) 12VDC
(0) None
(4) Remote Maint.
(0)
(1)
(2)
(3)
(0) N/A
(F) Factory Mutual / UL
N/A
FCC (USA)
DOC RSS-119
DOC RSS-122 (Canada)
This information is subject to configuration and change. Contact MDS
to verify certification.
Figure 1-1. MDS 4310 Model Number Codes
MAIN PRINTED CIRCUIT BOARD PCB VARIATIONS
The MDS 4310 Transceiver may be equipped with a 2314Axx main PC board or a 2013Axx
main PC board. The significant difference is the frequency range. Although the two PC
boards are similar, this manual covers transceivers with the 2314Axx main PC board which
has a frequency range of 350 to 512 MHz. Refer to manual part number MDS 05-2141A01
for specific information regarding transceivers equipped with the 2013Axx main PC board
which has a frequency range of 390 to 470 MHz. See Figure 1-2 for the location of the main
PCB part number label.
The main PC board part number can be identified without removing the housing cover. Refer
to Figure 1-1 to determine the transceiver frequency range. The frequency ranges identified
with a G, H I, J, K, L, M or N are equipped with the 2314Axx main PC board. The main PC
board part number can also be determined by using the HREV command via the HHT or
terminal. The HREV command displays the main PC board part number and the revision level.
The nominal frequency operating range of the transceiver PCB can also be determined by
using the MOD command via the HHT or terminal. The MOD command displays the main PC
board model number and the revision level.
See Chapter 3 –Programming and Diagnostics for detailed information on the use of the
Hand-Held Terminal.
1-4
GENERAL
MDS 05-2415A01, Rev. A
PRINTED CIRCUIT
BOARD MODEL
LABEL
1
3
2
4
1
3
2
4
1
2
3
Figure 1-2. Printed Circuit Model Number Location
SPECIFICATIONS: MDS 4310 DATA TRANSCEIVER (2314 MAIN PC BOARD)
General
Frequency Range:
Operating Bands—
any one of eight:
Frequency Programming:
TX/RX Spacing:
Primary Power—
Model 4310 Transceiver
Voltage:
TX Supply Current:
RX Supply Current:
Standby Current (Radio Inhibited) :
Connector:
Fuse:
Reverse Polarity Protection:
350–512 MHz (Nominal)
350–370 MHz, 370–390 MHz, 390–410 MHz,
406–430 MHz, 430–450 MHz, 450–470 MHz,
470–490 MHz, and 490–512 MHz
Programmable in 6.25 kHz increments to any
channel pair in radio operating sub-band.
0 (Simplex), 5 MHz, 10 MHz standard; others
are possible, consult with factory.
13.8 Vdc Nominal
(10.5–16.5 Vdc Operating Range)
2.0 A typical, 2.5 A Maximum, at 13.8 Vdc
Varies with power output adjustment
65 mA typical, without options installed or
LED indicators turned OFF
14 mA maximum
Integral part of power cable assembly
(Six foot/1.8 meter cable assembly included)
3.0 A, 3AG, FB (Fast Blow);
Holder part of cable assembly
Diode across primary power input with
internal 4 A plug-in fail-safe fuse.
Continued on next page.
MDS 05-2415A01, Rev. A
GENERAL
1-5
General Continued
Model 4350 and 4355 Packaged Radios
Voltage:
DC Supply:
TX Power Consumption:
RX Power Consumption:
Transient Protection:
Dimensions:
Model 4310 Transceiver
Model 4350 Packaged Radio
Model 4355 Packaged Radio
Weight:
Model 4310 Transceiver
Model 4350 Packaged Radio
Model 4355 Packaged Radio
120/220 Vac with 5 ampere-hour
Battery Back-up (Standard)
12, 24, 48, & 125 Vdc (Optional)
Positive, Negative;
Floating Ground with 24, 48, & 125 Vdc
50 watts maximum at rated output
5 watts maximum
2500 Volt Isolation on Voice Frequency (VF)
Inputs and Outputs, Power Supply & Keying
2.0" x 5.62" x 7.25"
50 x 143 x 184 mm
(Not including mounting hardware or
connector housings)
9.5" x 17.5" x 19.5"
241 x 445 x 495 mm
(Not including mounting hardware or
connector housings)
6.5" x 11.85" x 13.75"
165 x 301 x 350 mm
(Not including mounting hardware or
connector housings)
Maximum 3.5 Lbs./1.6 kg
w/all options installed
Maximum 33 Lbs/15.0 kg
w/all options installed
Maximum 21 Lbs/9.53 kg
w/all options installed
Transmitter
Frequency Range:
Operating Bands—
any one of eight:
350–512 MHz (Nominal)
350–370 MHz, 370–390 MHz, 390–410 MHz,
406–430 MHz, 430–450 MHz, 450–470 MHz,
470–490 MHz, and 490–512 MHz
Programmable in 6.25 kHz increments to any
channel pair in radio operating sub-band.
0 (Simplex), 5 MHz, 10 MHz standard; others
are possible, consult with factory.
Frequency Programming:
TX/RX Spacing:
1-6
GENERAL
MDS 05-2415A01, Rev. A
Power Output:
Duty Cycle:
Output Impedance:
Forward & Reflected Power Detector:
Frequency Stability:
RF Channel Bandwidth:
Spurious & Harmonic Emissions:
TX Response Time:
Modulation Type:
Deviation:
Time-Out Timer:
Analog Model Audio Input
Characteristics—
Level:
Frequency Response:
Soft Carrier Dekey:
Transmitter Keying:
PTT Delay:
MDS 05-2415A01, Rev. A
5 Watts/+37 dBm (standard)
at the ANTENNA Connector
Adjustable down to 0.5 watt/+27 dBm
100%/Continuous
50 Ohms
Built-in
± 0.00015% (1.5 PPM), –30°C to +60° C,
For All Models
12.5 kHz (25 kHz Compatible)
–65 dBc
≤ 4 ms
FSK—With 4800 and 9600 bps modems
FM—With 1200 bps AFSK modem
±2.5 kHz Maximum
Internal; Programmable from 1–255 Seconds,
or Off
Adjustable, –20 to +10 dBm
for 2.5 kHz Deviation
Model 4310: 600 Ohms, Unbalanced
Model 4350: 600 Ohms, Balanced,
4-Wire Audio
Model 4310: +1 dB, –3 dB, 50–3000 Hz
Model 4350: +1 dB, –3 dB, 300–3000 Hz
Programmable from 0 to 255 ms in 1 ms steps
Soft Carrier Dekey factory set to…
0 ms with no internal modem
0 ms with MDS 1200 baud modem
2 ms with 4800 FSK internal modem
4 ms with 9600 FSK internal modem
Positive-going and negative-going,
TTL-compatible keying inputs are provided.
Inputs will operate with signal voltages
between 5 and 40 volts. Dry contact closures
are also suitable. Keyline input pins have an
input impedance of 10 kilohms and have builtin over-voltage protection up to ±40 volts.
Programmable from 0-31 ms in 1 ms steps
GENERAL
1-7
Receiver
Frequency Range:
Operating Bands—
any one of eight:
Frequency Programming:
Type:
Frequency Stability:
Sensitivity for Analog Models:
(at ANTENNA connector)
Bit Error Rates:
Intermodulation:
IF Selectivity:
Desensitization:
Spurious and Image Rejection:
Analog Audio Output Characteristics—
Frequency Response (Refer. to 1 kHz):
Level:
Harmonic Distortion:
RF Channel Bandwidth:
Received Signal Strength Indicator (RSSI):
Squelch Opening Time:
1-8
GENERAL
350–512 MHz (Nominal)
350–370 MHz, 370–390 MHz, 390–410 MHz,
406–430 MHz, 430–450 MHz, 450–470 MHz,
470–490 MHz, and 490–512 MHz
Programmable in 6.25 kHz increments to any
channel pair in radio operating sub-band.
Double Conversion Superheterodyne
±0.00015% (1.5 PPM) –30° to +60° C,
For All Models
12 dB SINAD at –117 dBm (0.3 µV)
w/de-emphasis OFF
12 dB SINAD at –119 dBm (0.25 µV)
w/de-emphasis ON
Analog/AFSK at 1200 bps:
BER 1x10–6 at –110 dBm
Digital/FSK at 4800 bps:
BER 1x10–6 at –110 dBm
Digital/FSK at 9600 bps:
BER 1x10–6 at –108 dBm
75 dB Minimum (EIA)
100 dB minimum at Adjacent Channel
(± 25 kHz, one generator method, 20 dB
quieting)
70 dB minimum (EIA) on 25 kHz channels
65 dB minimum (EIA) on 12.5 kHz channels
85 dB Minimum
Model 4310—Basic Transceiver:
Filtered, +1, –3 dB, 50 – 3000 Hz
Model 4310—with VOX Board:
Filtered, +1, –3 dB, 50 – 3000 Hz
Unfiltered, +1, –3 dB, 50 – 4500 Hz
Model 4350:
Filtered, +1, –3 dB, 300 – 3000 Hz
Adjustable, – 20 to + 5 dBm
Model 4310: 600 Ohms, Unbalanced
Model 4350/55: 600 Ohms, Balanced
< 3%, All Models, Measured w/de-emphasis
12.5 kHz (25 kHz compatible)
Built-in, Range: –120 dBm to –60 dBm
2 ms
MDS 05-2415A01, Rev. A
Diagnostics & Programming Interface (through INTERFACE connector)
Signaling Standard:
RS-232C Interface
Connector:
DB-25
I/O Devices:
• MDS Hand-Held Terminal
• IBM PC or compatible computer with CGA,
EGA, VGA or Hercules Graphics™,
DOS 2.0 or later and 640K of memory.
System Data Characteristics (through INTERFACE connector)
Signals:
without modem
Transmit Audio Input
Filtered Receiver Audio Output
Receiver Unsquelched Sensor (RUS)
Received Signal Strength Indicator (RSSI)
Out-of-Lock Alarm
PTT/ PTT
added with internal modem
RS-232 Compatible Data Lines
RXD
TXD
RTS
CTS
DCD
DSR
ETC*
TC*
RC*
* w/synchronous FSK only
Data Rates—
AFSK:
FSK:
Data Turn-Around Time:
CTS Delay:
MDS 05-2415A01, Rev. A
50 to 9600 bps—Asynchronous audio
interface using external modems
30 to 1200 bps—Asynchronous w/internal
Bell 202T compatible modem
50 to 4800 bps—Asynchronous, w/internal
direct FSK interface
4800 bps—Async/Synchronous, w/internal
direct FSK interface
9600 bps—Async/Synchronous, w/internal
direct FSK interface
10 ms, including RTS/CTS time delay with
internal modem installed
5 to 255 ms,
Programmable in 1 ms increments
GENERAL
1-9
Environmental
Temperature Range:
Full Performance: –30°C to + 60°C
Operational Performance: –40°C to +70°C
95% at + 40°C Non-Condensing
Model 4310–Die-Cast Aluminum
Humidity:
Case:
Model 4350–Die-cast aluminum inside a
NEMA 4 Outdoor Housing, w/Padlockable
Latches
Model 4355–Die-cast aluminum inside a
NEMA 4 Outdoor Housing, w/Padlockable
Latches
AGENCY APPROVALS
FCC:
Underwriters Laboratories (UL)*:
Part 15.247 FCC approved
UL Approval for Class 1, Div. 2; Groups
A, B, C and D; hazardous locations
Factory Mutual (FM)*:
FM Approval for Class 1, Div. 2; Groups
A, B, C and D; hazardous locations
* These certifications available on special orders.
FCC INFORMATION (USA)†
Transmitter Model:
Channel Capacity:
Frequency Tolerance:
Output Power :
(Continuously Variable)
Necessary Bandwidth:
Emission Designators:
† Contact
PART 90
E5M5LL2013
1
±0.00015%
F1D:
F2D:
F3D:
0.1 to 2 watts
12.5 kHz
16K0
16K0
16K0
0.1 to 5 watts
25 kHz
16K0
16K0
16K0
MDS for information on availability and governmental approvals in other countries.
OPTIONAL EQUIPMENT, ACCESSORIES and CERTIFICATIONS
The MDS 4310 Data Transceiver can be supplied with the following options. For information
on adding options to MDS radios, please contact the MDS Marketing Department.
Special Certifications
Some models of the MDS 4300 Series transceivers are available with either Factory Mutual
(FM) or Underwriter’s Laboratory (UL) Approval for operation in Class I, Groups ABCD,
1-10
GENERAL
MDS 05-2415A01, Rev. A
Division 2, hazardous locations. Please consult with the MDS Marketing Department for
further information on these models.
1200 BPS Bell 202T Modem (Internal)—P/N 03-1815A01
The internal AFSK Bell 202T compatible modem is available for low speed data
requirements. It is used at slower standard speeds (30–1200 bps) and provides compatibility
in a radio system operating with non-MDS brand analog radios. A standard RS-232 C or TTL
compatible interface is provided through the radio’s INTERFACE (DB-25) connector.
4800 BPS Modem(Internal)—P/N 03-1831A01
This intermediate speed digital FSK interface (50–4800 bps asynchronous or 4800 bps
synchronous) can be used in any MDS 4300 Series remote radio. It is compatible with MDS
4100 Series digital master station radios using this modulation technique.
A standard RS-232 or TTL compatible interface is provided through the radio’s INTERFACE
(DB-25) connector.
9600 BPS Modem (Internal)—P/N 03-1833A01
The MDS internal 9600 bit per second (bps) FSK modem provides synchronous or
asynchronous operation where high speed data exchanges are required. The modem is
compatible only with MDS 4100 Series digital master station radio systems operating at
9600 bps. Available with RS-232 or TTL interface provided through the radio’s INTERFACE
(DB-25) connector.
Audio Processing Module (Internal)—P/N 03-2301A01
The Audio Processing Module can be installed to support applications where no keying
circuits are provided by a modem or remote terminal unit (RTU). The assembly senses the
presence of a tone on the transmit audio line and keys the transmitter. The VOX assembly
provides for audio signal pre-emphasis and de-emphasis if needed. This option is mounted in
the Option 1 position on the transceiver’s main board. See Appendix J.
Order Wire Module (External)—P/N 02-1297A01
The Order Wire Module option is supplied as an external device that plugs into the radio’s
INTERFACE (DB-25) connector. It can be used with a standard four-pin modular telephone
handset to provide a temporary voice link back to the master site for installation and test
purposes.
The order wire uses a voice-operated transmit (VOX) circuit to key the transmitter when the
operator speaks into the handset. Otherwise, normal operation of the remote transceiver
continues since the order wire option is installed in-line between the transceiver and the
RTU/modem. See Appendix E.
Remote Maintenance Module (Internal)—P/N 03-1958A01
With a Remote Maintenance Module installed in the Option 2 slot, three levels of diagnostics
are available—Mode 1: Local Diagnostics, Mode 2: Advanced Diagnostics, and Mode 3:
Remote Maintenance.
Continued on next page.
MDS 05-2415A01, Rev. A
GENERAL
1-11
Remote Maintenance Module Continued
When Mode 1 (Local Diagnostics) is enabled, the following parameters are available:
• RSSI
• Forward and reflected transmit power
• VSWR
• Transceiver internal ambient temperature
• Phase lock loop (PLL) lock condition
• Primary power and internally regulated voltages
This information is available locally through the HHT or a PC running MDS Remote
Diagnostic software (P/N 06-1972A01)
In Mode 2: Advanced Diagnostics mode, the diagnostics information available locally can
also be retrieved over-the-air through an MDS 4100 Series Master Station. The results are
displayed on a personal computer running MDS 2000 Diagnostics and Control System
software.
Mode 3: Remote Maintenance provides the highest level of diagnostics capability. When
Remote Maintenance is enabled, all of the above features are available plus local or over-theair control of the following parameters:
• RF Power Output Setting
• Frequency Offset
• Modem Data Deviation
Certain hardware elements must be present in the Remote and Master Stations for the Remote
Maintenance feature to be enabled. Also, the transceiver must be properly programmed at the
factory, or in the field using the HHT or a PC. If you ordered your radio system with Remote
Maintenance capability, all of these elements will have been installed and tested at the
factory.
If Remote Maintenance is being added to the system, refer to the instructions included with
the upgrade kit for detailed installation procedures (Publication Number 05-2104A01).
Consult the factory if you have questions regarding the capabilities of your existing system.
When using Remote Maintenance over the radio link, MDS 2000 Diagnostics and Control
Software is required. Refer to the instructions included with the software for detailed
installation procedures (Publication Number 05-1919A01).
Hand-Held Terminal Kit (External)—P/N 02-1501A01
The Hand-Held Terminal (HHT) allows the service technician to make certain key
performance checks on the transceiver without removing the radio from its mounting
position, and without the need for additional test equipment. In addition, the user can
program the receive and transmit frequencies in the field, as well as other parameters.
Refer to Chapter 3 for information on connecting and using the HHT.
RS-232 to RS-422 Converter Assembly—P/N 01-2358A01
An optional RS-232 to RS-422 adapter plug (P/N 01-2358A01) is available to allow direct
connection of an RS-422 circuit to the INTERFACE connector of a radio configured for RS-232
operation. An RS-422 connection may be required if the length of the interface cable exceeds
50 feet (15.24 meters).
1-12
GENERAL
MDS 05-2415A01, Rev. A
TTL to RS-232 Converter Assembly—P/N 03-2223A01
An optional TTL to RS-232 converter is available to allow direct connection of RS-232
equipment (such as an RTU or HHT) to a radio that has been configured for TTL operation.
This unit connects between the transceiver INTERFACE connector and the external equipment,
making the transceiver appear as an RS-232 device.
TOP COVER
COVER SCREWS
OPTION 1—
Modem PC Assembly or
Audio Processing Module
OPTION 2—
Remote Maintenance Module
or Diagnostic & Loopback Module
TRANSCEIVER
PC BOARD
BOTTOM
COVER
INTERFACE
CONNECTOR
LED ANNUNCIATOR
DISPLAY
DC POWER
INPUT
ANTENNA
DETACHABLE & ADJUSTABLE
MOUNTING BRACKETS (2)
Figure 1-3. MDS 4310 Transceiver—Major Assemblies
MDS 05-2415A01, Rev. A
GENERAL
1-13
This page intentionally blank
1-14
GENERAL
MDS 05-2415A01, Rev. A
CHAPTER 2—INSTALLATION
DANGER
The MDS 4310-HL Data Transceiver is approved for use in
Class I, Groups ABCD, Division 2, Hazardous Locations.
The installer of these transceivers MUST be familiar with
hazardous location installation guidelines before
installation or maintenance is begun. Do not begin
installation of or make external connections to this device
unless the area is known to be non-hazardous.
Refer to Appendix H of this manual for further information
on the approved conditions under which the MDS 4310-HL
can be installed in hazardous locations.
OVERVIEW
The MDS 4310 data transceiver is designed to be part of a data communications system.
Three critical objectives must be met during the installation—a good antenna system,
adequate stable primary power and the correct interface between the transceiver and the
external data equipment.
MDS 4310 transceivers are shipped with final test data sheets from the Manufacturing Test
Department. The test data sheets contain radio hardware and software configuration
information and actual performance measurements. Included in the data sheets are the
transmit and receive frequency (as measured), receive sensitivity, transmitter power output
and modulation characteristics, as well as pre-programmed loopback code. In most cases, the
transceiver requires no alignment during installation.
The following installation steps are for a typical installation.
1. Install the antenna transmission line, and preset the antenna heading.
2. Mount the transceiver vertically or horizontally on a stable surface.
3. Measure and install the primary power for the transceiver.
4. Verify that the unit serial number and loopback code are the same as found on the
test data sheet.
5. Verify that the transceiver’s operating frequencies are as listed on the operating
license. Check the license against the measured frequencies shown on the test data
sheet.
6. Verify interface requirements and protocol—
If no modem is installed…
• Check the transmit audio input level.
• Check the receive audio output level.
• Check the keyline operating characteristics—Ground or +5 Vdc can be used to
key the transmitter. Make sure the correct pin is wired on the transceiver’s
INTERFACE connector.
MDS 05-2415A01, Rev. A
2-1
OVERVIEW Continued
If a modem is installed…
• Check the modem’s configuration switch, if applicable, to verify the modem
configuration. (This applies to 4800 and 9600 bps modems only. Refer to tables
B-1 and C-1 for switch settings.) Is it compatible with the external data
equipment attached to the transceiver? The internal modem configuration is
based on data collected from the customer when the order was placed.
• Will the external data equipment provide asynchronous or synchronous data?
(This applies to 4800 and 9600 bps modems only.)
• Will the external data equipment operate with Data Set Ready (DSR)
continuously held high? Most data equipment will, and this line is tied high
inside the radio.
• Request to Send (RTS) functions as transmitter keyline.
7. Connect the antenna, primary power and external interface equipment as required to
the transceiver.
8. Check the transceiver’s power output and antenna system VSWR (or reflected
power).
9. Key the transmitter and optimize transmit and receive signals through refinement of
the antenna heading.
10. Verify basic system operation by establishing data communications between the
remote and the master stations.
This should complete the basic steps in the installation of the transceiver. More detailed
information will follow in this chapter should the user experience difficulties or choose to
make more detailed operational checks.
SURFACE MOUNTING
Using the supplied bracket, the MDS 4310 Data Transceiver can be mounted in any position
inside heated or unheated equipment buildings. For outdoor mounting, the unit must be
mounted in either a customer-supplied weatherproof housing or the MDS 4350/MDS 4355
packaged enclosure. The MDS 4310 die cast package withstands casual water, such as drips,
occasional spills, or condensation, but it is not suitable for continuous exposure to rain or
wind-driven moisture.
There are two mounting footprints that can be used. Choose the one that best suits your
installation situation. See Figures 2-1 and 2-2 for details and dimensions.
NOTE
The mounting brackets must be fastened to the transceiver
housing with #6-32 x 5/16 inch screws. Longer screws will
penetrate the housing and damage the main printed circuit
board.
2-2
INSTALLATION
MDS 05-2415A01, Rev. A
To install the unit:
1. Choose a location to allow easy access to the fasteners so that the entire unit can be
readily removed for service or replacement, yet allows viewing of the LED
indicators on the front of the case.
2. Fasten the brackets to the mounting surface with a 1/4 inches (M6) bolt, screw, or lag
screw (fasteners not provided) through the four holes in the mounting bracket.
3. If mounting surface is uneven, use three fasteners instead of four to prevent warping
of the mounting bracket.
5.6 inches
143 mm
2.0 in.
51 mm
2.25 in.
57 mm
ANTENNA
D C IN
IN T E R F A C E
KL TX
RX
AAAAAAAAAAAAAA
D C IN
OL
Figure 2-1. Mounting Dimensions—Front View
MOUNT BRACKETS WITH
THESE TWO HOLES FOR
ALTERNATE MOUNTING
2.75 in.
70 mm
7.25
inches
184 mm
USE ONLY
#6-32 x 5/16 INCH
SCREWS
6.75 inches
171 mm
8.5 inches
216 mm
Figure 2-2. Mounting Dimensions—Bottom View
MDS 05-2415A01, Rev. A
INSTALLATION
2-3
EXTERNAL CONNECTIONS
The following section describes how to connect external equipment to the transceiver in
typical installations. These recommendations may not be appropriate for all locations; local
electric wiring or fire codes may prescribe unique standards. The US National Electrical
Code is commonly the basis for local wiring guidelines and is recommended in the absence
of local standards.
DANGER
The MDS 4310-HL Data Transceiver is approved for use in
Class I, Groups ABCD, Division 2, Hazardous Locations.
The installer of these transceivers MUST be familiar with
hazardous location installation guidelines before any installation or maintenance is begun. Do not begin installation of
or make external connections to this device unless the area
is known to be non-hazardous.
Refer to Appendix H of this manual for further information
on the approved conditions under which the MDS 4310-HL
can be installed in hazardous locations.
ANTENNA
Connector
The ANTENNA Connector on the front panel of the MDS 4310 is the RF connector. See Figure
2-1. It is an industry standard female type “N” connector and mates with a standard type “N”
male connector, such as Amphenol 3900 (MIL Type UG-21) for RG-8 cable.
The exact mating connector type depends on the cable used. If large diameter rigid or semirigid coaxial cable is used for the feedline (see Antenna and Feedlines section), use a short
length of RG-8 or RG-214/U cable between the transceiver and the feedline. A three foot
section of RG-214/U cable with connectors at both ends (P/N 19-1323A01) is available from
MDS. This flexible interface eliminates tight bends in the feedline and reduces bending,
mechanical stress on the feedline and connectors.
+13.8 DC (Primary
Power) Connector
The radio can be powered from +13.8 Vdc power source connected through J2 on the
transceiver’s front panel. A custom power cable with an integral fuse and a molded mating
connector is provided with the radio. The lead with the integral fuse is the positive + line and
the lead with no fuse is the negative – line.
This power cable has an in-line fuse rating of three amperes (3A); do not use a substitute
cable without providing some type of external current limiting (fuse) protection for the radio.
INTERFACE
Connector
On the left side of the front panel is the INTERFACE connector, J1, consisting of a standard 25pin female “D” style connector. It mates with male connectors of the same series, such as the
ITT CANNON DB-25-P. These connectors are manufactured by many firms and are
available from distributors or from most retail electronics stores.
2-4
INSTALLATION
MDS 05-2415A01, Rev. A
NOTE
Do not use a full RS-232 cable for connection to the INTERFACE
connector. Cross-coupling between wires in the cable can cause
improper operation. Use only the pins required for the
application. (Refer also to Note 2 in Table 2-1.)
INT
ER
FA
C
E
TR
TD
MR
IN
CD
13.8
V
+ DC
–
AN
TE
NN
A
RD
DATA AND
MODULATION
INTERFACE
DC POWER
INPUT
13.8 VDC
ANTENNA CONNECTOR &
TRANSMISSION LINE
Figure 2-3. External Connections
Radios without internal modems…
The INTERFACE connector allows a unbalanced 600Ω voice frequency interface to the radio
with additional pins for transmitter keying (PTT), alarm, and diagnostic indications.
When an optional MDS internal modem is installed…
The INTERFACE connector allows a standard RS-232 interface. The full handshake
implemented includes TXD, RXD, RTS, CTS, and DCD. DSR is true whenever the radio and
modem are powered up, and the transmitter is automatically keyed when RTS goes high.
CTS is raised after the programmable delay (factory default is 10 ms), to allow time for the
synthesizer to change frequency and for the receiver at the other end of the link to unsquelch.
This time can be modified by the user to suit specific system timing requirements with the
HHT.
When equipped with an optional internal modem, the MDS 4310 “SMART” Data
Transceiver interfaces directly to any data terminal or RTU that supports the Bell 202,
RS-232 format. This considerably simplifies installation, since the levels between the radio
and modem can be preset at the factory, eliminating field measurements or adjustments. PTT
control and delay are handled automatically by the radio with the RTS/CTS handshake. Even
with the internal modem, the MDS 4310 “SMART” Data Transceiver allows programming
and diagnostic information to be accessed without disassembly of the transceiver enclosure.
MDS 05-2415A01, Rev. A
INSTALLATION
2-5
When using an internal modem, other pin functions of the DB-25 INTERFACE connector, such
as PTT, Receive Audio, Transmit Audio and RSSI are still active and should normally be left
open (unterminated). Connecting these pins to a computer terminal that also uses these pins
for auxiliary connections can cause improper operation.
Pin connections for the transceiver’s INTERFACE connector are summarized in Table 2-1 and
are described in greater detail later in this chapter.
NOTE
When using the TTL interface option, external 1 kΩ (1/8 W)
pull-up resistors are required between J1 Pins 2, 3, 4, 5 & 6 and
the logic source in the remote terminal unit (RTU).
Table 2-1. DB-25 Interface Connector Pin Functions
13
1
25
14
Viewed from Outside or from Plug’s Solder Cups
Pin Number and Function
Pin Number and Function
1.
Shield
14.
Push-To-Talk (PTT)*
2.
Transmit Data In (TXD)*
15.
Transmit Clock (TC)
3.
Received Data Out (RXD)
16.
Push-To-Talk (PTT)*
4.
Request-To-Send (RTS)*
17.
Receive Clock (RC)*
5.
Clear-To-Send (CTS)
18.
+13 Vdc
6.
Data Set Ready (DSR)
19.
+8 Vdc
7.
Signal Ground
20.
No Connection
8.
Data Carrier Detect (DCD)
21.
9.
Transmit Audio Input*
Received Signal Strength Indicator
(RSSI)
10.
Receiver Unsquelched Sense
22.
11.
Receiver Filtered Audio Output
Loopback Test–Receive Audio Input*
(For local testing of loopback DTMF
decoder)
12.
Radio Disable*
23.
Open Diagnostics
13.
Transmit Audio Output
24.
External Transmit Clock (ETC)*
25.
Out-of-Lock Alarm
* Input
2-6
INSTALLATION
MDS 05-2415A01, Rev. A
NOTES For Table 2-1
1. The radio is configured as DCE (data circuit-terminating equipment), as opposed to
DTE (data terminal equipment).
2. When using an internal modem, other pin functions of the DB-25 INTERFACE
connector, such as PTT, Receive Audio, Transmit Audio and RSSI, are still active
and should normally be left open (unterminated). Connecting these pins to an
external device such as a computer, RTU or PLC that also uses these pins for
auxiliary connections can cause improper operation. The use of an interface cable
that connects only the required pins is recommended.
3. Pins 1-8 are standard RS-232-C lines.
INTERFACE
Connector Pin Functional Descriptions
The following description covers the INTERFACE connector pin functions. The pin
descriptions are identical whether or not a modem is installed.
PIN 1: Shield
Connected to ground (negative supply potential) at the radio PC board.
PIN 2: TXD—Transmitted Data Input
without modem
This pin is connected to the data input port of the microcontroller and is used with
an external programming terminal.
with internal modem
As above, this pin is also connected to the data input port (TXD) of the internal
modem and is RS-232 compatible.
PIN 3: RXD—Received Data Output
without modem
This pin is connected to the data output port of the microcontroller and is also
used with an external programming terminal.
with internal modem
As above, this pin also provides an RS-232 compatible output of data received by
modem.
PIN 4: RTS—Request-To-Send Input
with internal modem
An RS-232 compatible input to modem which keys transmitter when RTS is at
logic “high”.
PIN 5: CTS—Clear-To-Send Output
with internal modem
An RS-232 compatible output to external RTU or terminal, which goes “high”
after the pre-programmed CTS delay time has elapsed.
MDS 05-2415A01, Rev. A
INSTALLATION
2-7
PIN 6: DSR—Data Set Ready
Provides a + 8 Vdc DSR signal to external terminal through a 1 kΩ resistor.
PIN 7: Signal Ground
Connected to ground (negative supply potential) at the radio PC board.
PIN 8: DCD—Data Carrier Detect
with internal modem
Provides an RS-232 compatible output. Goes “high” when the modem detects a
carrier from the master station.
PIN 9: Transmit Audio Input
without modem
The transmit audio input pin is normally connected to the audio output from the
associated modem or RTU. The input impedance is 600 ohms, and the deviation is
factory set so that an input level of –10 dBm produces a nominal transmitter
deviation of 2.5 kHz. This is the correct deviation level for most 12.5 kHz systems
and will also provide satisfactory service in most 25 kHz systems.
The deviation can be adjusted to fulfill the requirements of equipment using audio
levels other than –10 dBm. See Chapter 3—Field Tests And Adjustments for
detailed alignment procedures.
If the distance to the modem or RTU is greater than five feet (1.52 meters), use a
twisted pair of conductors to connect the transmit audio circuit. Connect one end
of the pair to the audio output terminals of the modem or RTU and the other end
to Pin 9 and Pin 7 of the INTERFACE connector.
with internal modem
The order wire audio output appears on Pin 9 whenever the external order wire
assembly is connected. Transmit audio from the modem is cut-off internally
within the transceiver when order wire is in use. This applies only to PTT. PTT
will not cut off the internal modem output.
PIN 10: Receiver Unsquelched Sense
This pin is not used in typical installations, but it is available as a convenience for
special applications. It is pulled up to +8 Vdc through a 1 kΩ resistor whenever
the receiver squelch is open, and pulled down to less than 1 Vdc when the squelch
is closed. The output resistance of 1 kΩ should be considered when interfacing
external equipment.
PIN 11: Receiver Filtered Audio Output—Line Level
This is the received audio output of the transceiver and is connected to the audio
input of the external modem or RTU. It will drive a 600 ohm load; the output
level is factory set to –10 dBm into 600 ohms for rated system deviation of
2.5 kHz on the received signal. Audio from the receiver discriminator is passed
through a 3 kHz low-pass filter before it reaches this pin. This response is ideal
for most external modems because it eliminates high frequency noise that can
degrade the bit error rate performance of the modem. The audio response is nearly
flat between 50 and 3000 Hz (no de-emphasis).
2-8
INSTALLATION
MDS 05-2415A01, Rev. A
PIN 11: Receiver Filtered Audio Output—Line Level (Continued)
If the distance to the modem or RTU is greater than five feet (1.52 meters), use a
twisted pair of conductors to make the connection. Connect one end of the pair to
the audio input terminals of the modem or RTU and the other end to pins 11 and 7
of the INTERFACE connector.
PIN 12: Radio Disable
A ground on this point will totally disable the radio, including transmit, receive,
modem and diagnostic functions. The pin controls the +8 Vdc used by all
transceiver circuits. The IN LED is lit when Pin 12 of the INTERFACE connector is
grounded. This input can be used to reduce power consumption during periods of
non-use.
PIN 13: Transmitted Audio Output
with internal modem
This is the audio output of the modulator IC in the modem and is provided for test
purposes.
PIN 14: PTT (Push-To-Talk )
This is one of two transmitter keying (PTT) inputs. The PTT input is normally at
ground. When this pin is pulled up to greater than 4 volts, the transmitter is keyed;
when the pin is at less than one volt (“open” circuit), the transmitter is off and the
receiver is active. See pin 16 description.
PIN 15: TC—Transmit Clock
This pin is used only on applications requiring a synchronous interface. This pin
provides a signal to clock transmit data bits out of the terminal connected to the
radio. The Transmit Clock signal is compatible only with RS-232 interfaces.
PIN 16: Push-To-Talk (PTT)
This is an active-low PTT input, pin 16, it acts in the opposite way from pin 14; it
is normally at 5 Vdc. When it is pulled down to less than one volt, the transmitter
is keyed; when it is greater than 3 volts (“open” circuit), the transmitter is off.
PIN 17: RC—Receive Clock
This pin is used only on applications requiring a synchronous interface. This pin
provides a clock signal to clock receive data bits from the radio to the terminal
connected to the radio. The Receive Clock signal is compatible only with RS-232
interfaces.
PIN 18: +13 Vdc Unregulated Source
This pin provides a convenient source of unregulated 13 Vdc at 0.5 A for
powering external low current equipment. This connection provides the primary
power to the radio with no regulation. Excessive drain on this connection will
blow fuse, F1, on the transceiver board.
MDS 05-2415A01, Rev. A
INSTALLATION
2-9
PIN 19: +8 Vdc Regulated Source
This pin provides a convenient source of regulated 8 Vdc at 10 mA for powering
external equipment.
PIN 20: No Connection
PIN 21: RSSI (Received Signal Strength Indicator)
A received signal strength indicator (RSSI) output is provided on this pin to aid in
steering antennas and monitoring changes in relative signal strength of received
signals.
Figure 2-4 is a graph plotting the typical RSSI voltage versus signal input. When
measured with a DVM, the accuracy of the RSSI is approximately ± 10 dBm. The
RSSI will be within 3 dBm when displayed on the HHT.
4
3.5
DC VOLTS
3
2.5
2
1.5
1
0.5
0
0
–4
–6
0
–8
–1
00
20
–1
–1
40
0
SIGNAL LEVEL (dBm)
Figure 2-4. Received Signal Strength Indicator Calibration Chart (Typical)
PIN 22: Loopback Test—Receive Audio Input
A direct input to the loopback and diagnostics module’s DTMF decoder. Can be
used with external DTMF encoder to simulate a polling request from a master
station. Nominal input signal level required: –10 dBm.
PIN 23: Open Diagnostics
A low on this input opens the diagnostics channel. If the terminal cable provides a
ground for this pin the diagnostics channel automatically opens. If this pin is not
grounded, the OPEN command is required from the HHT or terminal to allow
diagnostics and control functions of the transceiver.
2-10
INSTALLATION
MDS 05-2415A01, Rev. A
PIN 24: ETC—External Transmit Clock
This pin is used only on applications requiring a synchronous interface with an
external device controlling the timing of the transmitted bits. The most common
application of this pin is where the MDS 4310 is connected to an external high
speed modem. In this case, a cross-over (“null-modem”) cable is required that
connects Pin 17 (RC) from one modem to Pin 24 (ETC) of the other, and vice
versa. In most instances, timing is controlled by the internal clock inside the MDS
4310 (from Pin 15), and Pin 24 should be left open. The External Transmit Clock
signal is compatible only with RS-232 interfaces.
PIN 25: Out-of-Lock Alarm
A logic low (≤ 0.5 volts) on this pin indicates normal operation. A logic high
(≥ 4 volts) indicates a failure in the main phase lock loop or TCXO, or a transmitter time-out condition. A logic high also causes the transmitter and receiver to
be shut down. This pin can be used as an alarm output, if the internal series
resistance of 1 kΩ is considered when designing an external interface circuit.
FRONT PANEL INDICATORS
The radio is supplied with a set of six light emitting diode indicators (LEDs) that provide
information on the status of key operating functions. The indicators can be disabled if the
jumper on the transceiver’s main board at J11, pins 2 & 2 is removed. With the pins bridged,
the display is enabled. There are two versions of the plastic label for the front panel of the
radio—one for radios without a modem installed (See Table 2-2), and one for radios with
internal modems (See Table 2-3).
Table 2-2. External Indicators
PWR TX CD
RTS TXD RXD
LED
FUNCTION
INDICATES
PWR
Power Indicator
Primary power is applied and is greater than 10
Vdc.
If this indicator is flashing, the VCO is out-of-lock.
All transmit and receive functions are disabled.
TX
Transmit
The transmitter is keyed and is on-the-air
CD
Carrier Detect
Receiver detects an on-channel signal and the
squelch is open.
RTS
Request To Send
The RTU is asserting a Request To Send signal.
TXD
Transmit Data
Reflects the current state of the Transmit Data
line from the Remote Terminal Unit (RTU).
LED OFF=0, LED ON=1
RXD
Receive Data
Reflects the current state of the Receive Data line
from the transceiver internal modem.
LED OFF=0, LED ON=1
MDS 05-2415A01, Rev. A
INSTALLATION
2-11
TRANSCEIVER CONFIGURATION JUMPERS
The 4310 Transceiver has three jumper blocks that configure the transceiver. The following
sections describe the use and function of these jumpers.
J11—TTL/RS-232 and LED Enable Jumpers
Jumper J11 configures two functions; the front panel LEDs and interface signal levels. See
Figure 2-5 and Table 2-4 for jumper details.
With J11 Pins 1–2 jumpered, the INTERFACE connector communications pulses are 0 or 5Vdc
and are commonly referred to as TTL. With no shunt across J11 Pins 1–2, U31 is enabled
providing standard + and -12 Vdc signals on the RS-232 compatible signals available at the
INTERFACE connector. A shunt across J11 Pins 1–2 disables U31 which is the RS-232 line
driver/receiver IC. With U31 disabled, the signal lines are not converted to RS-232 12Vdc
levels.
The function of J11 pins 3–4 allows the disabling of the LED indicators on the transceiver
front panel. Disabling the LEDs allows less current consumption in solar-powered
installations and other current sensitive installations. With J11 pins 3–4 jumpered the LED
driver IC is enabled and the LEDs function. Conversely, when the jumper is removed from
J11 pins 3–4 the LED driver IC is disabled and the LEDs do not function.
CAUTION
To prevent possible damage to the interface circuitry,
disconnect primary power and the INTERFACE connector
before changing jumpers. J11 Pins 1-2 must be shunted if
any of the input/output lines are to be operated at TTL levels.
Failure to do so can damage the transceiver or RTU or may
cause intermittent operation.
PRINTED CIRCUIT
BOARD MODEL
LABEL
J1
EXTERNAL
INTERFACE
1
2
3
4
J16
FULL DUPLEX
INTERFACE
2
4
1
3
J11
RS–232 DISABLE
LED ENABLE
J14
RX AUDIO
NORMAL/INVERT
TCXO
FREQUENCY
ADJUSTMENT
1
2
3
Figure 2-5. Location of Configuration Jumpers
2-12
INSTALLATION
MDS 05-2415A01, Rev. A
Table 2-4. J11–External Interface TTL/RS-232
and Front Panel LED Configuration
LOCATION
SHUNTED
OPEN
1–2
TTL Enabled
RS-232 Converter Enabled*
3–4
Front Panel LEDs Enabled*
Front Panel LEDs Disabled
* Standard factory configuration
J14—Receiver Audio Output Phase
The receiver audio output phase can be shifted by 180 degrees (inverted) through the use of a
programmable jumper on the transceiver’s motherboard at J14—Audio Normal/Inverted. The
table below shows the possible positions of the jumpers. See Figure 2-5 for the board
location of the jumper and Figure 2-6 for details. Do not move this jumper from its factory
setting without first consulting MDS Systems Engineering.
Table 2-5. J14 Receiver Audio Output Normal/Inverted
LOCATION
SHUNTED
1–2
Normal Audio*
2–3
Inverted Audio
* Standard factory configuration
J14
1
2
3
Figure 2-6. Detail of Configuration Jumpers—J14
J16—Full Duplex Option Connector
J16 Pins 1–2 and J16 Pins 3–4 must be jumpered for normal remote operation. The Full
Duplex Option Connector is used only when the MDS 4310 is paired with another MDS 4310
transceiver for full duplex operation. Do not move these jumpers from the factory settings
without first consulting MDS Systems Engineering.
MODEMS—GENERAL
Introduction
MDS offers three modem interfaces for the MDS 4310 Data Transceiver operating at
1200, 4800 and 9600 bits per second. Details on each modem are provided in separate
appendices at the end of this manual. Any one model of the modems can be installed in
MDS 05-2415A01, Rev. A
INSTALLATION
2-13
the transceiver or in the MDS 4350/MDS 4355 packaged system, provided a
complementary Interface/Utility board is installed in the MDS 4350/MDS 4355.
The following is a general discussion of modem interface signaling.
The Role of the Modem
The purpose of the modem is to convert RS-232 data passing through the external
INTERFACE connector into digital signals that will modulate the transmitter, and to convert
signals recovered from incoming radio signals into RS-232 data. The modem is also
responsible for accepting RTS (Request To Send) from the INTERFACE connector and for
acknowledging transmitter operation with a CTS (Clear To Send) signal through the
INTERFACE connector to the attached equipment.
RTS and CTS Signals
When RTS on the INTERFACE connector goes high, the transmitter is keyed by the RTS
line connected to the modem. Whenever the transmitter is keyed, a timer is started that
will, after a programmed time period, raise the CTS line at the INTERFACE connector. This
CTS time delay allows time for the transceiver’s transmitter and the master’s modem
circuitry to stabilize before data can be sent to the master station. CTS is programmable
in 1 ms increments within the range of 5 to 255 ms. MDS recommends a minimum of 10
ms of CTS delay for optimum system performance. Thus, 10 ms is the factory default.
When RTS goes low, the transmitter is unkeyed and CTS is set to low.
DCD Signal
When the squelch circuit in the receiver senses the presence of a carrier, the DCD line
goes high. When the squelch circuit in the receiver senses the lack of a carrier, the RXD
output is forced to a “Mark” condition and the DCD signal is set low. RXD and DCD are
signals on the INTERFACE connector.
POWER REQUIREMENTS
The MDS 4310 Transceiver can be powered from any source with a nominal terminal voltage
between 12 and 15 volts direct current and capable of supplying a minimum of 2.5 amperes.
NOTE
Under no circumstances should the nominal supply voltage
drop below 10.5 volts or rise above 16.5 volts. The supply must
be sufficiently regulated to limit any change in its output
voltage to one volt or less when the transceiver alternates
between transmit and receive.
The power output is factory adjusted for 5.0 watts at 13.8 volts. If the actual supply voltage is
not 13.8 volts under load, the transceiver’s power output should be adjusted to 5.0 watts
before the unit is put into service.
One approach to powering the MDS 4310 Transceiver from a 120 Vac source and providing
for backup power during power outages is to float charge a 12 volt storage battery from a
regulated 13.8 Vdc power supply. The radio can then be connected directly across the battery
terminals. The power supply should be equipped with current limiting to protect it in the
event the battery becomes deeply discharged during a long outage.
2-14
INSTALLATION
MDS 05-2415A01, Rev. A
The battery used should be designed for deep discharge service. Such batteries are available
from industrial battery distributors and retail outlets, where they are sold as power sources for
recreational vehicles or for electric trolling motors for sport fishing.
ANTENNAS AND FEEDLINES
Antenna Selection and Mounting
A directional Yagi or corner reflector antenna is required by the FCC for use on all remote
stations to minimize interference to and from nearby systems. Good antennas of this type are
available from a number of manufacturers. Some 450 MHz directional antennas are listed
below.
Manufacturer
Model Number
Antenna Specialists ----------- ASP-604
Sinclair-------------------------- SRL-307
SRL-307RC-HD
SRL-350
Telewave ----------------------- ANT450Y10
Scala ---------------------------- CA5-450
CA7-460
CL-400
RA5-450
The antenna manufacturer’s recommended mounting configuration for a particular antenna
must be strictly followed. Use the proper mounting hardware and bracket to ensure a secure
mounting arrangement with minimal pattern distortion. Any metallic object close to the
antenna will distort the radiation pattern and, in severe cases, detune the antenna enough to
cause a high VSWR on the antenna feedline.
CAUTION
Strong fields near the antenna can interfere with the operation
of low level RTU circuits and change the reported values of
the parameters being monitored. Also, objects in the near
field of the antenna can increase VSWR and distort the
antenna pattern, resulting in reduced system performance.
The antenna should always be mounted at least 10 feet
(≈3 meters) from the radio, RTU, sensors, and other
components of the system.
When installing the antenna:
1. Mount the antenna in a clear space as far as possible from obstructions such as
buildings, metal objects, foliage, etc. The importance of this matter cannot be
overstated.
2. Make sure that the field is clear in the direction of the master station.
3. Orient the antenna in the direction of the master station if the direction is accurately
known. Preferably, monitor the signal from the master station with a DC voltmeter
connected to the radio’s RSSI pin (Pin 21 on the DB-25 connector), and rotate the
antenna for maximum indication.
MDS 05-2415A01, Rev. A
INSTALLATION
2-15
NOTE
A Yagi antenna can be oriented for either horizontal or vertical
polarization. All systems using a gain type omni-directional
antenna at the master station employ vertical polarization of the
signal; therefore the remote antenna must also be vertically
oriented, with its elements perpendicular to the earth’s surface.
If the antenna is mounted with its elements parallel to the
ground (horizontal polarization), the received signal strength
can be reduced by 20 dB or more.
Feedline Selection
Choice of correct feedline (the coaxial cable that connects the radio to the antenna) for the
particular circumstances of each installation is very important; poor cables can seriously
degrade system performance and low loss cables, while superior, can be quite expensive.
For example, 100 feet (30.48 meters) of RG-58A/U cable (commonly used for low frequency
operation) has an insertion loss of 13 dB at 450 MHz. A 5 watt transmitter operating into
such a feedline would produce only 250 milliwatts at the antenna; a similar loss in receiver
sensitivity would result and no amount of gain at the receiver can recover the signal lost in
the feedline. On the other hand, a 100 foot (30.48 meters) length of 1 5/8 inch HELIAX has a
loss of 0.55 dB at the same frequency, but its cost is many times greater than RG-58A/U.
In any point-to-multipoint system there will be a distribution of remote stations, with some
closer to the master station than others. For the close-in units, feedline loss is not as
important, and 6 dB or more of loss can be acceptable. For the furthest-out remote units, each
decibel of loss directly affects bit error rate and the amount of time the system misses polls
due to fading. Here, it is good practice to keep feedline losses well under 3 dB, with a target
loss of only 1 dB.
NOTE
For each 3 dB of feedline loss, half the transmitter power is lost
and twice the receiver signal is needed to produce the same bit
error rate.
RG-8 or RG-214/U cable is widely available and inexpensive. It is suitable for close-in
remote units or for those installations with short feedlines. For longer feedlines and lower
losses, HELIAX® or similar cable is a good choice. Table 2-6 shows the maximum length of
various types of cable that can be used to give 1, 3, 6 or 9 dB feedline loss.
Table 2-6. Signal Loss versus Cable Length and Type
CABLE TYPE
LENGTH IN FEET (AND METERS)
TO PRODUCE INDICATED LOSS AT 450 MHz
1 dB
6 dB
9 dB
RG-8
18 (5.49)
54 (16.46)
109 (33.22)
163 (49.68)
1/2 inch Foam HELIAX
66 (20.12)
199 (60.66)
397 (121.01)
596 (181.66)
7/8 inch Foam HELIAX
120 (36.58)
260 (79.25)
719 (219.15)
1079 (328.88)
582 (177.39)
1165 (355.09)
1747 (532.49)
1-5/8 inch Foam HELIAX 194 (59.13)
2-16
3 dB
INSTALLATION
MDS 05-2415A01, Rev. A
Feedline Installation
It is absolutely essential that the feedline connectors be installed in accordance with the
manufacturers’ instructions for the particular type of connector used. Also, any special
tooling required for mounting the connectors must be used, to ensure maximum mechanical
and electrical reliability. Be careful to check that the finished center pin dimensions are
within specifications to prevent damage to mating connectors when the two are joined.
Connectors that are exposed to outdoor environments must be sealed to prevent moisture
buildup in the connector. In extreme cases, rainwater can get into a connector and fill the
entire feedline with water, creating a high loss cable that will have to be replaced. There are
several good methods for weatherproofing these outside connections; consult the cable or
connector manufacturer for their recommended materials and procedures.
The feedline itself must also be installed carefully to prevent short-term or long-term damage.
Short-term damage can consist of kinking, twisting or excessive elongation of the cable
during installation. Harmful long-term effects could be due to improper connector sealing, a
bend that is too tight, insufficient strain relief on the cable when mounted on the tower, or
excessive flexing and vibration due to wind.
MDS 05-2415A01, Rev. A
INSTALLATION
2-17
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2-18
INSTALLATION
MDS 05-2415A01, Rev. A
CHAPTER 3
PROGRAMMING AND DIAGNOSTICS
INTRODUCTION
A significant feature of the 4310 Transceiver is the ability to accomplish many radio
programming and diagnostic tasks through software commands issued from a Hand-Held
Terminal (HHT).
Software control of the transceiver allows measurement and adjustment without removing the
top cover. In addition, when the Remote Maintenance feature is installed and enabled, many
of the same programming and diagnostic functions can be accessed over the RF channel,
thereby eliminating the need to travel to an installation site to perform minor checks and
adjustments.
This chapter explains how to connect the HHT to the transceiver, open the Diagnostics
Channel, and enter commands on the HHT keyboard. Step by step examples are used to
support the programming and diagnostic instructions.
Table 3-2 includes a complete list of HHT commands. Experienced users may wish to refer
directly to the table when programming or diagnosing the transceiver.
TERMINAL CONNECTION AND STARTUP
Connecting the HHT to the transceiver is simple, since the HHT interface cable includes a
DB-25 adapter plug that allows direct connection to the radio’s INTERFACE connector.
NOTE
Before connecting the HHT to the transceiver, verify the radio
is connected to a continuous +13.8 Vdc supply. (Most often the
transceiver is powered continuously, but some solar-powered
systems operate on an intermittent basis, making an alternate
power source mandatory for testing.) MDS also recommends
using a dummy load on the A N T E N N A connector of the
transceiver during all testing. This prevents accidental
interference to the rest of the radio system.
To connect and startup the HHT, follow these steps:
1. Remove the RTU interface cable from the INTERFACE connector on the transceiver
and set it aside. This step is not required for the MDS 4355 packaged system.
2. Plug the HHT into the INTERFACE connector as shown in Figure 3-1. If it is a MDS
4355 packaged system, plug the HHT into J3 of the Interface/Utility assembly as
shown in Figure 3-2.
3. Press and hold the ENTER key as the HHT runs through its self-check, a click will be
heard from the HHT, then release the ENTER key.
MDS 05-2415A01, Rev. A
3-1
4.
This completes the HHT startup procedure. After a five second “quiet time” (no
reception of radio signals), the Diagnostics Channel may be opened as outlined
below.
INT
ER
FA
C
E
TR
TD
MR
IN
CD
AN
TE
13.8
V
+ DC
–
NN
A
RD
F5
F4
F3
F2
F1
B
A
L
CTR
ESC
IFT
SH
Y
X
W
V
U
●
0
=
,
+
T
S
R
Q
P
9
8
7
#
–
O
N
M
L
K
6
5
4
)
*
J
I
H
G
F
3
2
1
(
/
E
D
C
TER
CE
EN
SPA
SP
BK
Z
Figure 3-1. Hand-Held Terminal Connected to the MDS 4310 Transceiver
3
F5
2
J7
TB2
F1
1
F4
CR7
J4
F2
F3
V3
J5
TB1
SW1
5
3
T2
2
6
1
4
3
V2
RS-232
INTERFACE
4
R10
J1
R28
5
R9
J3
25
6
T1
2
V1
1
J6
J3
Figure 3-2. MDS 4355 Packaged Transceiver
3-2
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
Special Instructions for Radios Configured as TTL
In most cases, an HHT can be plugged directly into the radio’s
INTERFACE connector and used immediately. However, in some cases,
the INTERFACE connector may have been configured for TTL operation
(as opposed to the more common RS-232 format) using the radio’s J11
jumper.
If you are unsure of which configuration you have, look at J11 on the
transceiver’s motherboard. In an RS-232 radio, J11 pins 1-2 will be empty
(open).
If your radio is configured for TTL, an optional TTL to RS-232 adapter plug
is available from MDS (P/N 03-2223A01) to allow connection of the HHT
or other RS-232 equipment, making the transceiver appear as an RS-232
device. Contact MDS for ordering information.
If the TTL to RS-232 adapter plug is not available, it is also possible to
temporarily reconfigure the INTERFACE connector for RS-232 operation
by removing the jumper on J11 pins 1–2. (See Table 2-4 for proper jumper
placement.) When testing is complete, J11 can be restored to its TTL
configuration.
NOTE
Plugging an HHT or a PC into a transceiver configured for TTL signaling
will key the radio transmitter, and will not allow terminal operation.
However, no damage will be done to the terminal or radio.
Opening The Diagnostic Channel
The diagnostic channel between the HHT and the transceiver is automatically opened when a
HHT is connected to the transceiver. However, if an older HHT or transceiver is being used,
it must be opened before HHT functions can be performed. To manually open the diagnostic
channel when using older HHTs or transceivers, follow the steps below:
1. After the HHT has completed its self-check, look for a solid flashing cursor on its
display. This indicates that the Diagnostic Channel is closed and that the HHT is
ready to accept the OPEN command.
2. Press ENTER . Wait at least five seconds to satisfy the required “quiet time.”
3.
After the five second quiet time, type OPEN +
4.
When the channel opens, the message "DIAGNOSTICS IS OPEN" appears.
ENTER
.
NOTE
If the Diagnostics Channel does not open the first time, wait at
least 5 seconds before trying again.
When the Diagnostics Channel is open, any keyboard entry is echoed by the transceiver and
appears on the HHT display. In radios that have a modem installed, the received data (RD)
and the transmit data (TD) LEDs will flash to indicate the exchange of information between
the HHT and the radio’s microcontroller.
The radio’s microcontroller and the modem share the communications lines connected to the
connector. In this way, no data will be passed through the modem to the
transmitted signal when the INTERFACE connector is connected to the HHT and the
diagnostics channel is open.
INTERFACE
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-3
CAPABILITIES OF THE HHT
With the HHT properly connected to the transceiver’s DB-25 INTERFACE connector, the
following can be performed.
• Review operating parameters and diagnostic information
• Set the operating parameters of the radio
• Program user information
All of these tasks can be performed with the radio mounted in its final operating position
without the need for removing the top cover of the transceiver enclosure.
Review Operating Parameters and Diagnostic Information
The user can review the current settings of various operating parameters of the radio, as well
as monitor several key test points in the radio. These parameters include:
• Radio model number, serial number and date of manufacture
• Transmit and Receive Frequencies
• Supply voltage, Lock voltage and Regulator voltage
• Transmit Forward Power Output
• Antenna Voltage Standing Wave Ratio—VSWR
• Time-out Timer Length
• Squelch Tail Eliminator Status*
• RTS/CTS Delay Interval
• Soft Carrier Dekey**
• Push-To-Talk Delay†
•
Temperature Inside Radio Housing
The values of diagnostic parameters (voltages, signal strength, etc.) are updated once every
second to allow the technician to make adjustments while observing the HHT display. In this
way, you do not need to invoke the diagnostic command each time a control is moved.
* The Squelch Tail Eliminator circuit senses the end of the incoming data message (by
detecting the loss of the 1200 Hz mark/idle tone), and shutting off the receiver’s
audio before the received carrier drops. In this way, the receiver does not
misinterpret the squelch tail noise burst as data. The Squelch Tail Eliminator feature
is only available on analog radios.
** The Soft Carrier Dekey feature keeps the transmitter keyed for a short period
(typically 4 ms or less) after the RTU has sent the last data bit to the transceiver. This
allows the modem time to process and transmit all of the characters in each message,
and reduces the possibility of framing or BCH (cyclic frames) errors.
† Push-to-Talk delay inserts a programmed delay (typically 5 to 31 ms) between the
time the RTS or PTT line is asserted and when the transmitter is actuated. This is
done to prevent carrier overlap (two stations transmitting at once) and other timing
problems that could otherwise occur in some systems, especially those with
repeaters. Carrier overlap causes lost or corrupted data.
3-4
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
Setting the Operating Parameters
The user can select and set several of the operating parameters of the radio. These parameters
include:
• Transmit Frequency
• Receive Frequency
• Time-out Timer Length
• Enable or Disable Time-out Timer
• Squelch Tail Eliminator Status
• RTS/CTS Delay Interval
• Soft Carrier Dekey Delay Length
• Loopback Code
• Push-To-Talk Delay
Program User Information
The user can program information into the radio that is specific to the individual user. This
information includes:
• Owner’s Name (20 characters total)
• Owner’s Specific Message
(For example—assigned location or date unit placed in service. 27 characters total).
This information is stored in EEPROM, and will remain programmed in the radio until new
information is entered.
USING THE HAND-HELD TERMINAL—Basic Operations
Command Syntax
The proper procedure for using the review commands is the command, followed by an ENTER
keystroke. For the programming commands, the appropriate command is followed by a SPACE
keystroke, followed by the information or values, then ENTER . See Programming Examples
for further information.
Shift Key
The shift key is used to access the numbers on the keyboard of the HHT. Pressing the SHIFT
key once locks the keyboard into the upper level character set; the SHIFT key has to be
pressed again to return to the main character (alphabet) set. Exception: Pressing the ENTER
key automatically returns the keyboard to the main character set.
Backspace (BKSP) Key
The Backspace key BKSP can be used to edit information or commands as they are being
entered with the keyboard. The backspace key works only when the SHIFT key has the
alphabet selected.
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-5
Error Messages
Listed below are common error messages that may be encountered when using the HHT.
"INCORRECT ENTRY"
Data was entered in a wrong format, or wrong number of digits.
"COMMAND ENTRY ERROR"
Command improperly entered, or an invalid command was tried.
"INCORRECT FREQUENCY ENTRY"
Last digit of frequency was omitted, or frequency entered was out of range.
"DIAGNOSTICS NOT INSTALLED"
Diagnostic Board not installed or not detected by radio’s microcontroller.
Closing the Diagnostic Channel
The diagnostic channel between the HHT and the transceiver is automatically closed when a
HHT is disconnected to the transceiver. However, if an older HHT or transceiver is being
used, it must be closed before returning the transceiver to service. To manually close the
diagnostic channel when using older HHTs or transceivers, type in CLOS + ENTER . The
message " DIAGNOSTICS IS CLOSED" will be displayed, indicating a closed condition. At this
point it will be noticed that either the running cursor or the stationary solid flashing cursor
returns, and that all further keystrokes will be ignored by the HHT, another indication that the
diagnostics channel is closed.
F3
F4
F5
A B C
F1
D
E
/
F
F2
(
1
G H
*
)
K
L
–
#
4
2
3
I
J
5
6
M N O
8
9
P Q R
S
T
,
0
+
U
V W X
CTRL
Z
7
=
●
Y
ESC
SHIFT
SPACE ENTER
BKSP
Figure 3-2. Hand-Held Terminal Keypad
NOTE
The Diagnostics Channel automatically closes after 15 minutes
of no keyboard activity. If this happens, simply re-open the
channel to resume transceiver testing.
PROGRAMMING EXAMPLES
Refer to Figure 3-2 or an actual HHT for the following discussion. The following is an
example of reprograming the MDS 4310 Transceiver in the field, using the HHT. The current
parameters of operation are:
• Transmit frequency = 428.0125 MHz
• Receive frequency = 438.0125 MHz
3-6
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
•
•
•
Time-Out Timer length = 30 sec
Soft Carrier Dekey = 0 ms
Squelch Tail Eliminator = On
The transceiver is to be programmed to operate in a system requiring the following
parameters:
• Transmit frequency = 428.8375 MHz
• Receive frequency = 438.8375 MHz
• Time-Out Timer length = 94 sec
• Soft Carrier Dekey = 4 ms
• Squelch Tail Eliminator = off
• Loopback Code = 1234
The list of steps and commands below will program the MDS 4310 with the required values.
1.
2.
Connect the HHT to the transceiver as previously outlined, and open the diagnostics
channel if necessary.
Verify the current frequencies by typing FRQ + ENTER . Display will read:
TX FRQ = 428.01250
RX FRQ = 438.01250
3.
Program the new transmit frequency by typing PTX + SPACE + SHIFT +
428.83750 + SHIFT + ENTER . Be sure to include the decimal point and all trailing zeros.
The display will read TX FRQ PRGMD TO 428.83750 MHZ if the information was entered
correctly and accepted by the microcontroller.
4.
Program the new receive frequency by typing PRX + SPACE + SHIFT
438.83750 + SHIFT + ENTER , again taking care to enter in all characters.
If the information was entered properly, and accepted by the microcontroller, the
display will read RX FRQ PRGMD TO 438.83750 MHZ.
5.
Program the time-out timer length by entering PTOT + SPACE + SHIFT
+ 94 + SHIFT + ENTER . The display will read TIME-OUT TIMER SET TO 094 SECS.
6.
Program the soft carrier time by entering PSCD + SPACE + SHIFT + 4
+ SHIFT + ENTER . Display will read SOFT CARR. DEKEY SET TO 004 MS.
7.
Disable the STE by typing DSTE +
ELIMINATOR OFF.
8.
The information entered in can now be reviewed by using the FRQ, TOT, SCD and
commands to review each setting.
9.
Enter the loopback code by typing PLBC + SPACE + SHIFT + 1234 + SHIFT
+ ENTER . The display will change and read LOOPBACK CODE = 1234.
ENTER
. The display will read SQUELCH TAIL
10. Close the diagnostics channel by typing CLOS +
ENTER
STE
before unplugging the HHT.
This completes the programming sequence.
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-7
PROGRAMMING OWNER’S INFORMATION
The information accessible by the OWM and OWN commands can be programmed by the user
to allow information unique to the radio transceiver or its location to be stored in the
EEPROM. Normally, this field is left blank on units as shipped from MDS.
To program these fields, proceed according to the following directions:
1.
2.
3.
4.
5.
Open the diagnostics channel.
Type in POWN + SPACE , followed by the owners’ name, etc. This is limited to a
maximum of 20 characters. When the desired information has been entered, press
ENTER . The display will read INFORMATION PROGRAMMED.
Type POWM + SPACE , followed by the desired message, not to exceed the maximum
of 27 characters. When the desired information has been entered, press ENTER . The
display will read INFORMATION PROGRAMMED.
Review the information by typing OWN or OWM to verify that the desired message has
been entered. If either message has an error in it, the information will have to be reentered using the above steps.
Close the diagnostics channel.
PASSWORD PROTECTION
If password protection of programmed information (frequency, owner’s name and message,
etc.) is used, the PASS command followed by the correct four-character password must be
entered before the transceiver programming can be changed. Without the proper password,
the programmed information and diagnostic data can only be reviewed, and no access to the
programming commands is possible.
For more information on password protection, contact the MDS Systems Engineering.
DIAGNOSTIC EVALUATION
Using the diagnostic commands, a technician can read important voltages and levels with the
HHT. These values are updated once every second, allowing adjustment of the levels without
the need for invoking the command each time a control is moved. Below is a list of the
commands, with the display to be expected after typing the command followed by an ENTER
keystroke.
------------- Supply voltage supplied to transceiver.
Display will read SUPPLY VOLTAGE = xx.x VOLTS.
VR ------------- Main regulator voltage.
Display will read +8V = xx.x VOLTS.
RSSI ---------- Received signal strength at ANTENNA connector.
Display will read RSSI = –xxx DBM.
LV ------------- PLL VCO lock voltage.
Display will read LOCK VOLTAGE = xx.x VOLTS IL.
SV
NOTE
The I L is an in-lock indicator; if the PLL is
out-of-lock, the display will show OL.
3-8
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
With the radio’s transmitter keyed…
FPWR ---------- Forward RF power output of Transceiver.
Display will read FWD POWER = xxx WATTS.
VSWR ---------- Calculated VSWR based on forward and reflected power levels.
Display will read VSWR= x .x : x.
Test Modes
Using the Hand-Held Terminal, a technician can invoke several diagnostic and test modes
that are useful in evaluating the operation of both the transceiver and an internal modem. The
test modes are invoked by typing the commands listed below followed by an ENTER
keystroke.
KEY
----- Keys the transmitter with the transmit modulation enabled.
DKEY ----
Unkeys the transmitter.
TEST_1 --
Keys the transmitter and enables a constant DTMF Loopback test tone. This
test is useful for measuring the radio’s diagnostic deviation level with a
communications monitor.
TEST_2 --
Disables the DTMF Loopback test tone and unkeys the transmitter.
TEST_5 -- Disables the transceiver’s VCO circuit.
TEST_6 -- Enables the transceiver’s VCO circuit.
TEST_7 -- Turns on the modem test tones and keys the transmitter for 12 seconds.
• With 1200 bps modem: 1200/2200 Hz tone.
• With 4800/9600 bps modem: Sine wave at 1/2 data rate (bps).
EQUIPMENT DIAGNOSTICS DEFINITIONS
Software is available for service personnel to use a MDS Master Station as a diagnostics tool
for system monitoring and maintenance. MDS 2000 Diagnostic and Control System software
uses the master station to transmit a special message to all remote radios in a given system
asking one remote radio at a time to respond with a test signal. The test signal is analyzed by
the master station and the results are displayed on the screen of a personal computer running
the MDS software. In order for the software to know which radios to poll for a test signal, an
“Equipment List” must be created by the system operator which describes the address of the
radio and its capabilities. The remote radio’s diagnostic address is referred to as its loopback
code in MDS documentation and software. For more information, refer to the MDS 2000
Diagnostics and Control System Software User’s Guide (MDS P/N 05-1919A01).
Since it is possible to have MDS 4310 radios of different capabilities installed in the same
system it is very important to know the exact profiles of each unit. The following are
descriptions of the various diagnostic capabilities available for the MDS 4310 Transceiver.
All of the diagnostic modes listed in Table 3-1 are available from MDS 4310 transceivers
with a Remote Maintenance Module (P/N 03-1958A01) properly installed in jacks J5 and J7
of the transceiver motherboard.
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-9
DIAGNOSTIC EXAMPLES
RF Power Output Check
Suppose you wish to read the transmitter output power while the HHT is connected. The
following steps will accomplish this.
1.
2.
Connect the transceiver to a dummy load.
Type KEY + ENTER , to key the transmitter.
3.
Type FPWR +
4.
As a further performance check, the DC voltage supplied to the transmitter can be
read by typing SV + ENTER .
5.
Unkey the transmitter by typing DKEY +
ENTER
, to display the forward power output level.
ENTER
.
Received Signal Strength Indication (RSSI) Check
To invoke the RSSI function, simply type RSSI + ENTER on the HHT. The display indicates
the signal level at the ANTENNA connector in dBm. The display is updated once every second.
This check can be especially useful when aiming the antenna at the remote site for maximum
signal level. By using the RSSI command and the continuously updated display, an installer
can aim the antenna in the direction of maximum field strength.
Table 3-1. Diagnostic and Control Capabilities
LEVEL
MODE
DESCRIPTION
Loopback
1
A radio set to Mode 1 diagnostics will respond to a poll containing a four-digit
number string called the “Loopback Code.” When the remote radio decodes
its loopback code transmitted by an MDS master station, it responds by
keying its transmitter for several seconds with a continuous modulating tone.
The radio’s signal strength and deviation can then be measured by the
Master Station.
Advanced
2
With a radio set to Mode 2, critical diagnostic information available through a
local HHT or personal computer is available over the RF channel to the
Master Station. This includes: transmitter RF power output, the primary
power supply voltage, the internal +8 Vdc regulated voltage level, the
synthesizer’s lock voltage and the radio’s internal temperature. In addition,
the diagnostic analysis of the remote unit’s signal, as received by the Master
Station receiver will be displayed on a personal computer connected to the
master station. These values include received signal level, carrier frequency
offset (error) and modulation level/deviation.
Remote
Maintenance
3
This is the highest level of diagnostics and control capability available for the
MDS 4310 transceiver. With Remote Maintenance enabled, all of the above
diagnostic capabilities are available and, in addition, many of the radio’s
parameters can be adjusted either locally with an HHT or over the RF
channel with a personal computer running MDS 2000 Diagnostic and Control
System software. Since it provides the greatest level of diagnostics and
control, many users prefer to keep the transceiver set to Mode 3 diagnostics.
3-10
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
PROGRAMMING AND TEST COMMANDS
Table 3-2 contains a list of all HHT programming and diagnostics commands.
NOTE
Some command strings in Table 3-2 include an underscore “_”
symbol to denote a SPACE key press. The underscore is a visual
reminder only, and should not be entered.
Table 3-2. Programming and Test Commands—Part 1 of 3
DIAGNOSTICS CHANNEL
OPEN ... OPEN the Diagnostics Channel
CLOS ... CLOSE the Diagnostics Channel
DISPLAY COMMANDS
HARDWARE STATUS
STAT ....Display status of hardware profile
Displayed below are the functions of each display character and its meaning.
1
2
3
Keyed Status ................ U – Unkeyed
K – Keyed
T – Timed Out
Diagnostic Mode .......... S – Standard (Mode 1)
A – Advanced (Mode 2)
R – Remote Maint. (Mode 3)
Diagnostic Hardware ... A – Installed, LBC Valid
B – Installed, LBC Invalid
C – Uninstalled, LBC Valid
D – Uninstalled, LBC Invalid
4
6
7
8
Diagnostic Module ....... I – Installed
U – Uninstalled5
Base/Remote .............. B – Base (High Side LO)
R – Remote (Low Side LO)
IF/LO Arrangement ..... 0 – 45 MHz/Low
RSSI Cal. Status .......... Y – Calibrated
N – Uncalibrated
RF Power Status.......... Y – Calibrated
N – Uncalibrated
OWNER’S INFORMATION
OWM ....Display Owner’s Message
OWN .... Display Owner’s Name
RADIO INFORMATION
HREV ... Transceiver hardware revision level
SER...... Serial number of radio
MD........Transceiver manufacture date
SREV ... Transceiver firmware revision level
MO ....... Model number of radio
OPERATING PARAMETERS
CTS ...... Displays CTS delay in ms
FRQ ..... Frequencies currently set in MHz
LBC ...... Display Loopback code (4 digits)
SCD
Display Soft Carrier Dekey in ms
PTT ...... Display Push-to-Talk delay in ms
STE ...... Display Squelch Tail Eliminator (STE)
Status— ON or OFF (Normally OFF if VOX
function is used.)
TOT ...... Display Time-out Timer length (sec)
DIAGNOSTIC INFORMATION
FPWR .. Forward RF power*
LV ........PLL VCO lock voltage
RPWR .. Reverse RF power*
RSSI ....Received Signal Strength Indicator*
SV........ Supply voltage to radio*
TEMP... Internal temperature in degrees Celsius*
VR ........ Regulator voltage output ≈8 Vdc*
VSWR .. VSWR at ANTENNA connector*
* Information is updated every second
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-11
Table 3-2. Programming and Test Commands—Part 2 of 3
DIAGNOSTIC AND TEST MODES
TEST MODES
KEY ......... Keys the transmitter
(Transmit modulation enabled)
DKEY ....... Dekeys the transmitter
TEST_1 ... Keys the transmitter and enables a constant
DTMF Loopback test tone. Useful for checking
the radio’s diagnostic deviation level
TEST_2 ... Disables DTMF Loopback test tone and
unkeys the transmitter.
TEST_5 .... Disables VCO
TEST_6 .... Enables VCO
TEST_7 .... Turns on modem test tones and keys the
transmitter for 12 seconds.
• With 4800/9600 bps modem: Sinewave at
1/2 data rate.
• With 1200 bps modem: 1200/2200 Hz tone.
DIAGNOSTIC MODES
MODE_1 .......... Enable-Standard Diagnostics
MODE_2 .......... Enable-Advanced Diagnostics
MODE_3_xxxx . Enable Remote Maintenance
Functions (xxxx is the data rate in bps)
NOTES– Remote Maintenance Module (03-1958A01)
must be installed to invoke these functions.
4-wire radios in Mode 3 must use 1200 as the
modem data rate.
DIAGNOSTIC CALIBRATION
These commands are used with calibrated test equipment attached to radio.
CPWR . Calibrate forward power to 5 Watts for diagnostics
RSSL ... Calibrate RSSI at –110 dBm
RSSH... Calibrate RSSI at –70 dBm
SET/PROGRAM COMMANDS
OPERATING PARAMETERS
PASS_xxxx ...... Password Entry
PSCD_xxx ....... Program soft carrier dekey; 2–255 ms,
no leading zeros (1–3 digits)
PTX_xxx.xxxx... Program transmit frequency†
ETOT
..............
Enable Time-out Timer
PRX_xxx.xxxx .. Program receive frequency†
DTOT
..............
Disable Time-out Timer
PLBC_xxxx....... Program loopback code (0000–9999)
PTOT_xxx
........
Program Time-out timer (sec)
ESTE ................ Enable Squelch Tail Eliminator
(1–3 digits)
PCTS_xxx ....... Program CTS Delay in ms; 2-255 ms, no
PPTT_xx
..........
Program Push-to-talk delay (0-31 ms)
leading zeros (1–3 digits)
† A move of more than 6 MHz requires re-alignment of the transceiver’s tuned circuits. Consult factory for details.
POWER, FREQUENCY AND DEVIATION
A Remote Maintenance Module (P/N 03-1958A01) must be installed in the transceiver and the transceiver must be set to
Mode 3 Diagnostic for these commands to have any effect. Electronic controls (EEPOTs) for these parameters are
incremented or decremented as a percentage of their maximum value—zero to 100 percent. Changes in these settings
are not permanent until the RMST command is sent.
GENERAL:
RMRD .............. Read present EEPOT settings
RMIST .............. Store present EEPOT settings
RMIS ................ Reset all EEPOTs to 50% and store
settings
RMOV .............. Restore all EEPOT to the previously
stored settings to 50%.
<SPACE> ........ Repeat last adjustment command
FREQUENCY:
IF ...................... Increment Frequency by 1
DF .................... Decrement Frequency by 1
INCF_xx ........... Increment Frequency by xx value
DECF_xx .......... Decrement Frequency by xx value
PRIMARY MODULATION:
ID ..................... Increment Deviation by 1
DD .................... Decrement Deviation by 1
INCD_xx ........... Increment Deviation by xx value
DECD_xx ......... Decrement Deviation by xx value
POWER:
IP ..................... Increment Power by 1
DP .................... Decrement Power by 1
INCP_xx ........... Increment Power by xx value
DECP_xx ......... Decrement Power by xx value
OWNER’S INFORMATION
POWN_xxxxx ....... Program owner’s name
(20 characters maximum)
3-12
POWM_xxxxx....... Program owner’s message
(27 characters maximum)
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
Table 3-2. Programming and Test Commands—Part 3 of 3
REMINDERS
•
•
•
•
•
•
All command entries end with the ENTER key.
Use the SHIFT key to access numbers; press again to return to characters.
Square cursor ( ) – letter mode is selected.
Rectangular cursor ( ) – number mode is selected.
Use ESC/BKSP key to edit information or commands being typed in.
An underlined blank space (xx_xx) on command list indicates a required space.
HAND-HELD TERMINAL SETUP DEFAULTS
Occasionally, users of the HHT will key in a sequence of characters that will alter the internal
microcontroller operating defaults and cause it to no longer be able to exchange data with the
radio. The following is a set of instructions for reinitializing the HHT for use with MDS radio
products.
Restoring the HHT Operation Defaults
1. Plug the HHT into the radio and apply power to the radio. A small rectangular cursor
will appear on the display.
2.
Put the HHT into the Setup Mode by pressing the following keys in sequence: SHIFT
+ CTRL + SPACE . The HHT responds with a screen display similar to that shown in
Figure 3-3.
F1
F2
F3
F4
F5
A
B
C
D
E
1
2
3
Figure 3-3. HHT Initialization Display
Reviewing and Changing Defaults
1.
2.
3.
The first of 15 menu items will be displayed. See Table 3-3. All of the items can be
reviewed by pressing the “NEXT” function controlled by the E key. The menu
parameter setting can be changed by pressing the “ROLL” function controlled by
the A key.
Set up the HHT as listed in Table 3-3.
To “EXIT” the setup mode, press C for “EXIT”, or it will automatically be closed
after the final item on the setup menu has been reviewed and the “ROLL” function is
selected.
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-13
Table 3-3. Hand-Held Terminal Operating Defaults
PARAMETER
SETTING
Re-init HT
NO
Baud Rate
1200
Comm bits
8,1, n
Parity Error
OFF
Key Repeat
OFF
Echo
OFF
Shift Keys
YES
Ctl Chars
PROCS
Scroll on
33rd
Cursor
ON
CRLF for CR
ON
Self Test
SLOW
Key Beep
ON
Screen size
32
Menu Mode
LONG
HAND-HELD TERMINAL WIRING
The HHT is a very reliable unit, but the 6-conductor coiled cord or its RJ-11-6 modular
connectors can be damaged by over-stretching or being dropped. The coiled cord is wired as
a straight pin-for-pin assembly and the parts required to construct a replacement cable can be
obtained from many electronics supply companies. Although similar in appearance, the cable
set is not the same as an RJ-11-4 (4-conductor) telephone coiled cord.
Adapter Plug Wiring
Figure 3-4 shows the internal wiring of the DB-25 interface adapter plug that is used to
connect the HHT to the transceiver.
RJ-11-6
DB-25
1
19
2
5
3
N/C
4
3
5
2
6
7
23
Figure 3-4. DB-25 Interface Adapter Wiring
HHT ALTERNATIVES
As an alternative to using the HHT, a PC running terminal software (such as PCPLUS™,
PROCOMM™, etc.) can be used to program the transceiver. Also, any ASCII terminal
3-14
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
supporting a standard RS-232 interface can be used. The software commands for PC or
ASCII terminal control are identical to those listed for the HHT. (See Table 3-2.)
The communications settings for a PC or ASCII terminal must be as follows:
• Bit rate = 1200 bps.
• Number of data bits = 8, 1 stop bit
• No parity
• Full duplex mode
• Caps Lock enabled
Cable Wiring for a PC or ASCII Terminal
CAUTION
When connecting a PC or ASCII terminal to the MDS 4310
Transceiver, use only the required pins specified below. Do
not use a straight DB-25 to DB-25 cable wired pin for pin.
The use of improper cables may cause equipment damage.
The cable connecting the PC or terminal to the transceiver must connect the TXD, RXD,
DSR and signal ground pins (DB-25 INTERFACE connector pins 2, 3, 6 and 7) as shown in
Figures 3-5 and 3-6. Pin 23 can be be connected to ground to automatically open the
diagnostic channel. If the PC or terminal is to be used for purposes other than diagnostics
or programming, do not connect Pin 23.
NOTE
A transceiver equipped with an internal modem can transmit
when connected to a PC, because of activation of RTS. Ensure
that the ANTENNA connector has a 50 ohm termination on it
before proceeding.
COMPUTER DB-9
TXD
RXD
RTS
CTS
GND*
DCD
RADIO DB-25
3
2
2
3
TXD
RXD
7
8
23
5
7
1
6
OPEN
GND*
DSR
* Signal Ground
FEMALE
MAL
Figure 3-5. DB-9 to DB-25 Interface Cable Wiring
COMPUTER DB-25
TXD
RXD
RTS
CTS
GND*
DCD
RADIO DB-25
2
2
3
3
TXD
RXD
4
5
23
7
7
8
6
OPEN
GND*
DSR
* Signal Ground
FEMALE
MALE
Figure 3-6. DB-25 to DB-25 Interface Cable Wiring
MDS 05-2415A01, Rev. A
PROGRAMMING AND DIAGNOSTICS
3-15
This page intentionally left blank.
3-16
PROGRAMMING AND DIAGNOSTICS
MDS 05-2415A01, Rev. A
CHAPTER 4
FIELD TESTS AND ADJUSTMENTS
DANGER
The MDS 4310-HL data transceiver is approved for use in
Class I, Groups ABCD, Division 2, Hazardous Locations.
The installer of these transceivers MUST be familiar with
hazardous location installation guidelines before any installation or maintenance is begun. Do not begin installation of
or make external connections to this device unless the area
is known to be non-hazardous.
Refer to Appendix H of this manual for further information
on the approved conditions under which the MDS 4310-HL
can be installed in hazardous locations.
GENERAL
This chapter describes field tests and adjustments that can be used to diagnose suspected problems or evaluate the transceiver after an assembly has been replaced. These tests are not
normally required for new installations (with the exception of checking the supply voltage to the radio and testing antenna system performance). Unless otherwise noted, the
procedures given here apply equally to the MDS 4310 transceiver and the MDS 4350/4355
packaged models. For additional set-up information on the MDS 4350 and MDS 4355, refer
to Appendices F and G respectively.
NOTE
All units are tuned at the factory for optimum performance. Do
not re-tune any unit without first checking the performance as
it is. Retuning may not be necessary.
TEST EQUIPMENT REQUIRED
Directional RF Wattmeter—It must be equipped with a plug-in element rated for 10 watts
and 1,000 MHz. A popular directional wattmeter suitable for this service is the Bird
Model 43 Thruline™ wattmeter with the Bird 10D element.
Service Monitor— This is an instrument that performs the combined functions of RF
and audio signal generator, frequency meter/counter, modulation analyzer and RF
watt–meter. Monitors are typically equipped with an input attenuator/dummy load
that allows the full output of the transmitter to be safely coupled directly to the
instrument. If this last feature is not provided, you will need a separate attenuator/dummy load. Suitable service monitors are manufactured by the IFR Division of
Regency, Inc., Marconi Instruments Ltd., and Hewlett Packard. It is also possible to
use separate test equipment in place of a service monitor, but this may be impractical
for field work.
Continued on next page.
MDS 05-2415A01, Rev. A
4-1
TEST EQUIPMENT REQUIRED Continued
Frequency measuring equipment usually requires a “warm-up” period to achieve
maximum accuracy; a warm-up period of 30 minutes is not uncommon. Please read
the unit’s instruction manual before proceeding with frequency measurements.
NOTE
FCC regulations require a frequency accuracy of .00015% (1.5
ppm). MDS transceivers meet this requirement by using
temperature compensated crystal oscillators. A frequency counter
used to set the transceiver on-frequency must have an accuracy
that is five to ten times better than what it is reading, which is an
accuracy of .00003% to .000015% (0.3 to 0.15 ppm).
If a frequency counter with a frequency accuracy of better than 0.3
ppm is not available, do not make any adjustments to the
transceiver frequencies.
DC Voltmeter—A digital voltmeter such as a Fluke 75 is suitable.
Oscilloscope—If the service monitor does not contain a low frequency oscilloscope, then
a basic one is required. The oscilloscope should have a frequency response of 100
kHz or higher, AC/DC coupling and have a horizontal sweep resolution of 2 ms per
division.
MDS Hand-Held Terminal (HHT)—Kit P/N 02-1501A01. The HHT is most
convenient way to set the operating parameters controlled by the transceiver’s microcontroller, and to use the built-in test and diagnostic features of the radio.
NOTE
To perform the tests in this chapter, operators must be familiar
with connecting the HHT, opening and closing the Diagnostics
Channel and issuing the required commands. Chapter 3—
Programming and Diagnostics contains complete instructions
for using the HHT.
If desired, a personal computer running a standard terminal emulation program such
as PCPLUS™ or PROCOMM™ can be substituted for the HHT. In this case, the
program should be set to 1200 bps, eight data bits, no parity, and one stop bit. The
keyboard must be set with the caps lock key pressed; the radio responds only to
commands and numbers entered in uppercase characters. The commands for a PC are
identical to those used with the HHT. (See Chapter 3—Programming and
Diagnostics, for more information.)
Room Thermometer—This thermometer should be accurate to 1°C. It is used to
calibrate the temperature sensor on the Remote Maintenance Module.
Power Supply—The output needs to provide 12–14 Vdc at 3 amperes or more.
Small, flat-bladed adjustment tool—It is used to adjust potentiometers on the
transceiver. It should be made of plastic or metal.
Data Terminal Emulator—This device is required for radios with a built-in modem
installed. It is used to key the transceiver and simulate incoming data on the DB-25
INTERFACE connector. A simple terminal emulator can be wired for this purpose as
4-2
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
shown in Figure 4-1. The transceiver’s INTERFACE connector must be configured for
RS-232 operation for proper operation of the emulator. (See “Special Instructions
for Radios Configured as TTL” below if your radio has been configured for TTL.)
NOTE
As an alternative to a Data Terminal Emulator, a “breakout
box” or jumpers can be attached to the transceiver’s INTERFACE
connector and configured with the proper connections as
shown in Figure 4-1.
Special Instructions for Radios Configured as TTL
In most cases, a data terminal emulator can be plugged directly into the
radio’s INTERFACE connector and used immediately. However, in some
cases, the INTERFACE connector may have been previously configured
for TTL operation (as opposed to the more common RS-232 format) using
the radio’s J11 jumper field.
If you are unsure of which configuration you have, look at J11 on the
transceiver’s motherboard. In an RS-232 radio, all pins on J11 will be
empty (open), with the possible exception of a jumper on Pins 13 and 14
(LEDs enabled). By contrast, a TTL radio will have jumpers installed on all
pins of J11, with the possible exception of Pins 13 and 14.
If your radio is configured for TTL, an optional TTL to RS-232 adapter plug
is available from MDS (P/N 03-2223A01) to allow connection of the Data
Terminal Emulator, an HHT or other RS-232 equipment. This unit plugs
between the transceiver’s INTERFACE connector and the external
equipment, making the transceiver appear as an RS-232 device. Contact
the factory for ordering information.
If the TTL to RS-232 adapter plug is not available, it is also possible to
temporarily reconfigure the INTERFACE connector for RS-232 operation
by removing the jumpers on J11. (See Table 2-4 for proper jumper
placement.) When testing is complete, J11 can be restored to its TTL
configuration.
CONSTRUCTING A DATA TERMINAL EMULATOR
Introduction
The right side of Figure 4-1 shows the proper wiring for a simple data terminal emulator.
There are two ways to construct the Data Terminal Emulator; both techniques are electrically
identical and use common parts available from most electronic parts supply stores. The
difference is in the packaging of the two units.
Emulator Design #1
Method 1 requires two small toggle switches (SW1 & SW2), and a DB-25 male connector
with a cover that is large enough to mount the toggle switches inside it. (See the top part of
Figure 4-2.)
Emulator Design #2
Method 2 requires two toggle switches (SW1 & SW2), a DB-25 male connector, a short
length of three-conductor cable, and a small enclosure. (See the lower part of Figure 4-2.)
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-3
RADIO
TRANSCEIVER
TERMINAL
EMULATOR
STANDBY
XMTR KEYED
+5 VDC
RTS
Pin 4
DSR
Pin 6
TXD
Pin 2
SW1
1K
Transceiver
Interface
Connector
SW2
Male DB-25
Connector
SPACE
MARK
Figure 4-1. Remote Data Terminal Emulator Wiring
SW1 and SW2 mounted inside a small enclosure
1 )
WS
S T
2 ) (R
W
S XD
(T
METHOD ONE
SMALL TOGGLE
SWITCHES (SPST)
SMALL ENCLOSURE
(Plastic or Metal)
SW1
(RTS)
SW2
(TXD)
TOGGLE SWITCHES
(SPST)
3 CONDUCTOR
CABLE
DB-25 MALE
CONNECTOR
METHOD TWO
Figure 4-2. Construction Options for Building a Data Terminal Emulator
4-4
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
Switch Functions
Listed below are the functions of the two toggle switches referred to in Figure 4-1. These
functions are called for in many of the test procedures which follow.
• Closing SW1 keys the transmitter by setting the RTS line high.
• SW1 must be closed in order for SW2 to emulate transmit data (TXD). Transmit data
is emulated as follows:
Closing SW2 emulates a “Space” condition.
Opening SW2 emulates a “Mark” condition.
REMOTE MAINTENANCE CONSIDERATIONS
General
If your radio is equipped with a Remote Maintenance Module (P/N 05-1958A01 installed in
Jacks J5/J7), some of the tests and alignments which follow must be done using software
commands from the Hand-Held Terminal (HHT) and not with the on-board adjustments.
The HHT icon shown below indicates that the paragraph to its immediate right describes an
action to be taken on transceivers equipped with Remote Maintenance.
The description given below is an example only, and is one of many descriptions of this type
in this manual. HHT programming and control commands are shown in uppercase BOLD
TYPE. Table 3-2 contains a complete list of HHT programming and control commands.
R
M
Use the SER command to read the serial number assigned to the transceiver.
NOTE
To perform the tests in this chapter, operators must be familiar
with connecting the HHT, opening and closing the Diagnostics
Channel and issuing the required commands. Chapter 3—
Programming and Diagnostics contains complete instructions
for using the HHT.
Presettings
The Remote Maintenance Module has three electronic potentiometers (EEPOTs) that are
electrically in parallel with the frequency, deviation and RF power potentiometers on the
transceiver motherboard. Before any alignment of the transceiver is started, the EEPOTs
must be preset to their initial settings (50%) using the RMIS command from the HHT. The
three potentiometers on the transceiver motherboard must then be preset to the positions
listed in Table 4-1.
After the potentiometers on the motherboard are preset, you should adjust the transmitter’s
output power (using the HHT) according to the instructions given in Test Procedure ➊. You
should then proceed with the required test procedures listed in Table 4-2.
NOTE
The settings of the EEPOTs can be checked at any time by
entering the RMRD command on the HHT keypad. The HHT
displays the settings of all three EEPOTs on one screen.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-5
Table 4-1. Main Circuit Board Potentiometer Settings for Remote Maintenance
DESIGNATOR
FUNCTION
POSITION
R69
TX Power Output
Maximum CW
R168
TX Deviation
Maximum CW
R69 and R168 are multiturn controls that should be advanced at least 10 turns, or until a
faintly audible clicking sound is heard from the potentiometer. This sound indicates the end
of the control’s range.
After these potentiometers are preset to the positions listed in Table 4-1, the technician
should adjust the transmitter’s output power (using the HHT) according to the instructions
given in the BASIC TRANSCEIVER TESTS section. (Page 4-7.)
Then, the technician should proceed with the required alignment procedures in the order
given below. A separate section is provided for each modem configuration installed in the
transceiver—no modem, 1200 bps, 4800 bps, and 9600 bps. These sections cover transceiver
adjustments for Transmit Frequency, Squelch, Deviation, and Receive Audio Output.
NOTE
To store Remote Maintenance adjustments, you must
type RMST. If the settings are not stored, the radio will
revert to the previous settings when the power is
removed from the transceiver.
INTRODUCTION TO FIELD TESTS & ADJUSTMENTS (See Figure 4-9)
The following test procedures in this chapter are arranged according to the hardware
configuration of the MDS 4310 transceiver. The primary difference between units is the
presence of a modem—no modem, 1200 bps modem, 4800 bps modem, or 9600 bps modem.
There is also a “Basic Tests” section that applies to all radio configurations, and a separate
section for adjustment and checkout of the Remote Maintenance Module (if one is installed).
Refer to Table 4-2 to locate the required tests and proceed directly to those sections that
apply to your radio. All of these procedures assume the radio is powered up and connected to
a dummy load or antenna as required.
Table 4-2. Test Procedure Reference Chart
For alignment instructions relating to...
4-6
Procedure
Basic Transceiver Checks—Applies to all radio configurations
➊
Radios with no internal modem installed
➋
Radios with a 1200 baud modem installed
➌
Radios with a 4800 baud modem installed
➍
Radios with a 9600 baud modem installed
➎
Remote Maintenance Module (with or without a modem installed)
➏
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
NOTE
The transmitter will be turned off by the time-out timer if the
transmit period exceeds the programmed time out value. To
continue testing, simply unkey and key the transmitter to reset
the timer. The factory default value for the time-out timer is
180 seconds.
If desired, the time-out timer may be disabled during these
tests, by sending the DTOT command from the HHT keypad. Be
sure to restore the timer to its original setting when testing is
complete.
NOTE
The Diagnostics Channel (the link between the HHT and the
radio) “times out” after 15 minutes of no HHT keypad activity.
If this happens, you will need to re-open the Diagnostics
Channel to resume transceiver testing.
TEST PROCEDURE ➊:
BASIC TRANSCEIVER CHECKS—Applicable to all hardware configurations
Introduction
This section describes basic checks that apply to all common configurations of the MDS
4310 transceiver. The checks covered are:
• Power supply
• Transmitter power output
• Antenna VSWR
These checks should be made before starting any detailed troubleshooting or alignment of the
transceiver. See Figure 4-9 for the locations of adjustable controls on the transceiver
motherboard.
Power Supply Check
1. Connect the power supply to the transceiver.
2. Remove the transceiver’s cover by loosening the four captive screws along the
perimeter of the case.
3. Measure the power supply voltage at the transceiver power connector.
R
M
4.
5.
With Remote Maintenance installed, the supply voltage can be checked by
entering the SV command on the Hand-Held Terminal.
If necessary, adjust the power supply voltage to 13.8 Vdc. If the voltage is not
adjustable, make sure the nominal value is between 12 and 15 volts.
Momentarily key the transmitter by the KEY and DEKEY commands.
The voltage should drop no more than 0.4 Vdc while the transceiver is keyed.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-7
Transmitter Power Output Check
1. Connect a directional wattmeter between the transceiver and the antenna feedline.
2. Connect the HHT to the transceiver and open the Diagnostics Channel.
3. Key the transmitter by entering KEY. This command keys the transmitter until the
DKEY command is entered (or until the time-out period has been reached).
4. Check the output power of the transceiver. If necessary, adjust it for the desired
level, or a maximum of 5 watts, using R69 on the transceiver motherboard. Do not
exceed 5 watts.
R
M
If Remote Maintenance is installed, set R69 fully clockwise and use the
IP / DP / INCP / DECP commands to adjust the output power. The IP / DP
commands increment/decrement the power in single steps while the INCP /
DECP commands make larger jumps by adding a space and a number to the
command. (Example: INCP_20 + ENTER to increase the power by 20 steps
out of 100). When finished, type RMST to store the setting.
CAUTION
In systems operating with battery power, make sure that the
battery is fully charged before attempting to set the
transceiver output power. If the power is set for 5 watts with
reduced battery voltage, the transceiver will put out more
power when the battery becomes fully charged, which may
cause a violation of FCC rules and drain the battery more
quickly than expected.
Antenna VSWR Check
1. Connect a directional wattmeter between the transceiver and the antenna feedline.
2. Key the transmitter by entering KEY. This command keys the transmitter until the
DKEY command is entered (or until the time-out period has been reached).
3. With the transmitter keyed, set the directional wattmeter to measure the power in the
reverse direction, to measure the reflected power from the antenna. This should read
less than 0.5 watt. If the reading is higher, problems with the antenna or feedline are
indicated. Check all connections and ensure that the cable connectors are installed
properly. Make sure the antenna is not damaged, and is the correct model for this
frequency band.
CAUTION
Do not put the radio into service until reflected power problems are corrected, as they can degrade system performance
and shorten equipment life.
4-8
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
If an in-line wattmeter is not available, the HHT can be used to obtain a rough
indication of the reflected power from the antenna system. Use FPWR to measure
forward power, and RPWR to measure the reflected power. The calculated VSWR can
be read using the VSWR command.
NOTE
The built-in power output and VSWR metering functions are
provided for the convenience of service personnel for making
quick checks of the radio’s performance. They are not
substitutes for calibrated test equipment.
4.
Dekey the transmitter and remove the directional wattmeter from the antenna circuit.
VCO Lock Voltage Adjustment
In order for the radio to switch quickly between transmit and receive, the VCO range
capacitor is adjusted so that the lock voltage does not change between transmit and
receive modes. This adjustment requires monitoring the lock voltage with a DC voltmeter
on the transceiver motherboard or on the HHT using the LV command if the Remote
Maintenance Module is installed.
1. Place voltmeter at test point shown in Figure 4-3 or use the HHT to measure the
VCO lock voltage. The voltage should be between 2 and 7 Vdc.
2. Key the radio with the KEY command.
3. Monitor the voltage. The nominal voltage is not important, it should not vary more
than one tenth of a volt between transmit and receive modes.
4. If the voltage difference is greater than one tenth of a volt, adjust the VCO RANGE
capacitor C247, on the transceiver PC board until the lock voltage is the same (± 0.1
Vdc) in the transmit and receive mode. C247 is available through the shield of the
VCO sub-assembly.
VCO LOOP
VOLTAGE
TEST POINT
VCO
ASSEMBLY
SHIELD
C247
VCO RANGE
(THRU SIDE OF
SHIELD)
Figure 4-3. VCO Lock Voltage Test Point
This completes the basic tests of the MDS 4310 Transceiver.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-9
TEST PROCEDURE ➋:
TRANSMIT FREQUENCY, SQUELCH, DEVIATION,
AND RECEIVE AUDIO OUTPUT—For Radios with No Internal Modem
Remove the cover from the transceiver by loosening the four captive cover screws and lifting
it straight up. See Figure 4-9 for the locations of adjustable controls.
Transmit Frequency
1. Connect the transceiver’s ANTENNA connector to the input of the service monitor
using a short length of RG-8/U or RG-214 coaxial cable.
2. Key the transmitter by entering KEY on the HHT or use the Transmit Test Switch.
The KEY command keys the transmitter until the DKEY command is entered or until
the time-out period has passed.
3. Measure the transmitter frequency. It should be within 100 Hz of the assigned
frequency. If not, adjust the transmitter frequency on the TCXO.
If Remote Maintenance is installed, use the IF / DF / INCF / DECF commands
instead of adjusting the Frequency Adjust on the TCXO. The IF / DF
commands increment/decrement the frequency in single steps while the
INCF / DECF commands make larger jumps by adding a space and a number
to the command. (For example: INCF_8 to increase the frequency by eight
steps out of 100.) When finished, type RMST to store the setting.
Unkey the transmitter and reconnect the interface cable to the external modem or
RTU.
R
M
4.
Receive Audio Output Level
The receive audio output level of the transceiver is factory-set for 0.7 Vp-p (–10 dBm) at
600 Ω, at rated system deviation. If a third party modem is used with the MDS 4310, consult
its instruction manual to determine what audio input level the modem needs. Should a
different level be required, adjust the Receive Audio Output Level, R292, on the transceiver
board as follows:
1. Generate an on-channel signal modulated with a 1 kHz tone, at the proper deviation
level (commonly 2.5 kHz), to provide an audio signal for adjustment purposes.
Monitor the level at the input to the modem (or at Pin 11 of the INTERFACE
connector) using the oscilloscope in the service monitor. Adjust R25 on the main
transceiver board for the desired level.
An alternate method is to adjust R25 when data signals from the master station are
present and audio tones can be seen on the scope.
2.
Reconnect the feedline directly to the ANTENNA connector of the transceiver. Place
the unit in normal operation with the associated master station.
Squelch Adjustment
1. Consult the RTU instruction manual to determine if squelch action in the radio is
required for normal operation. If squelch action is not required, set Squelch
Threshold, R41, fully counterclockwise (open squelch) and skip the remaining steps
of this procedure. If you are unsure on this point, assume that squelch action is
required and perform the following procedures.
2. Remove the feedline from the ANTENNA connector.
4-10
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
3.
4.
5.
Using an oscilloscope set for DC coupling at 2 V or 5 V per division, observe the
Receiver Unsquelched (RUS) signal at Pin 10 of the INTERFACE connector.
Insert an on-channel signal at –120 dBm (.225 µV), with a 1 kHz tone and 2.5 kHz
deviation. Adjust R41 fully counterclockwise while observing the oscilloscope
display.
Set the squelch to be fully closed at this signal level by advancing R41 until the
oscilloscope pattern changes from about 8 V to 0 V. Watch for noise on the scope
display, and advance R41 slightly farther, if necessary, until the signal level remains
at about 0 V.
Transmitter Deviation
1. Inject a test tone equivalent to the RTU audio output level (typically 1200 or
2200 Hz) into the radio at Pin 9 of the INTERFACE connector.
2. Key the transmitter by entering KEY on the HHT, or by grounding the radio’s “not”
PTT line (Pin 16).
3. Observe the deviation on the service monitor, and adjust it to 2.5 kHz using R168,
TX DEV.
If Remote Maintenance is installed, set R168 fully clockwise and use the
ID / DD / INCD / DECD commands to adjust the deviation. The ID / DD commands increment/decrement the deviation in single steps while the INCD /
DECD commands make larger jumps by adding a space and a number to the
command. (Example: INCD_4 to increase the deviation by four steps out of
100.) When finished, type RMST to store the setting.
4. Unkey the transmitter using the DKEY command.
5. Close the Diagnostics Channel and disconnect the HHT from the transceiver.
Putting Things Back Together
1. Reconnect feedline and interface cables to transceiver, and reinstall the cover.
2. Confirm that the unit operates properly with the associated RTU. (Typically, the
transceiver should be transmitting intermittently in response to polling signals from
the master station.
3. Secure all cables, providing strain relief if necessary, and check connectors for
tightness.
R
M
This completes the set-up of the MDS 4310 transceiver without a modem installed.
TEST PROCEDURE ➌:
TRANSMIT FREQUENCY, SQUELCH, DEVIATION,
AND RECEIVE AUDIO OUTPUT—For Radios with MDS’s Internal 1200 BPS Modem
In the following procedures, references to SW1 & SW2 relate to the switches of the Data
Terminal Emulator (Figures 4-1). See Figure 4-2 for an assembly drawing of the 1200 baud
modem. See Figure 4-9 for the locations of adjustable controls on the transceiver mother–
board.
Continued on next page.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-11
TEST PROCEDURE ➌: (Continued)
TRANSMIT FREQUENCY, SQUELCH, DEVIATION,
AND RECEIVE AUDIO OUTPUT—For Radios with MDS’s Internal 1200 BPS Modem
Set-up
1. Remove the cover from the transceiver by loosening the four captive cover screws
and lifting it straight up.
2. Connect the HHT and open the Diagnostics Channel.
3. Connect the transceiver’s ANTENNA connector to the input of the service monitor
using a short length of RG-8/U or RG-214 coaxial cable.
4. Close the Diagnostics Channel and disconnect the HHT.
5. Connect the Data Terminal Emulator to the INTERFACE connector.
Transmit Frequency
1. Key the transmitter by raising RTS (SW1 Closed/SW2 Open). This generates a
continuous Mark tone.
2. Measure the transmit carrier frequency; it should be within 100 Hz of the assigned
frequency. If not, adjust the transmitter frequency using the Frequency Adjustment
on the TCXO.
R
M
If Remote Maintenance is installed, use the IF / DF / INCF / DECF commands
instead of adjusting the TX Frequency Adjustment control on the TCXO.
The IF / DF commands increment/decrement the frequency in single steps
while the INCF / DECF commands make larger jumps by adding a space and a
number to the command. (For example: INCF_8 to increase the frequency by
eight steps out of 100.) When finished, type RMST to store the setting.
Data Deviation
1. Adjust the service monitor to read modulation deviation. With the transmitter still
keyed (SW1 Closed), the deviation should be 2.5 kHz ±100 Hz. If not, adjust R168,
TX DEV. for the proper deviation.
If Remote Maintenance is installed, set R168 fully clockwise and use the
ID / DD / INCD / DECD commands to adjust for 2.5 kHz deviation. The
ID / DD commands increment/decrement the deviation in single steps while
the INCD / DECD commands make larger jumps by adding a space and a
number to the command. (Example: INCD_4 to increase the deviation by four
steps out of 100.) When finished, type RMST to store the setting.
Measure the Mark tone frequency. It should be 1200 Hz ± 10 Hz. If not, adjust R2 on
the modem board.
Close SW1 and SW2 to generate a Space tone.
Check the transmitter’s deviation. It normally falls within 0.5 kHz of the Mark tone’s
deviation.
Measure the Space tone’s frequency. It should be 2200 Hz ± 10 Hz. If not, adjust R3,
Space, on the modem board.
Unkey the transmitter by removing the Data Terminal Emulator.
Turn off S1-3 on the modem PC board.
R
M
2.
3.
4.
5.
6.
7.
4-12
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
8.
9.
10.
11.
12.
13.
14.
15.
Generate an on-channel signal at –60 dBm (225 µV), with 1 kHz modulation at
2.5 kHz deviation.
Adjust the transceiver’s R25 for 1.2 Vp-p ± 0.05 V at U3 pin 8 (on the main
transceiver PC board) as read on the oscilloscope.
Set the service monitor modulation frequency to 1700 Hz.
Touch the oscilloscope probe tip to the top of chip resistor R33 on the modem board.
Adjust R25 (on the modem) for a square wave on the scope. Remove the probe.
Turn off the service monitor and disconnect the coax from the transceiver’s ANTENNA
connector.
Adjust the squelch by observing the receiver audio output signal at Pin 11 of the
INTERFACE connector using an oscilloscope.
Adjust R41 on the transceiver’s motherboard fully counterclockwise, and observe the
noise voltage on the oscilloscope. Now slowly rotate R41 clockwise to a point just
beyond that where the noise disappears. Watch the scope for a few seconds and, if
necessary, continue to advance R41 until the receiver remains fully squelched (the
noise no longer appears intermittently).
R25
RECEIVE DATA
DETECTOR
THRESHOLD
ADJUST
R2
MARK TONE
(1200 HZ)
FREQUENCY
R33
R3
SPACE TONE
(2200 HZ)
FREQUENCY
J6
J8
R33
RX TEST POINT
Figure 4-4. 1200 bps AFSK Modem; MDS P/N 03-1815AXX
See Table A-1 in Appendix A for details on switch settings.
Squelch Adjustment
1. Using an oscilloscope set for DC coupling and 2 V or 5 V per division, observe the
Receiver Unsquelched (RUS) signal at Pin 10 of the INTERFACE connector.
2. Insert an on-channel signal at –120 dBm, with a 1 kHz tone and 2.5 kHz deviation.
Adjust R41, Squelch Threshold, fully counterclockwise while observing the
oscilloscope display.
3. Set the squelch to be fully closed at this signal level by advancing R41, Squelch
Threshold, until the oscilloscope pattern changes from about 8 V to 0 V. Watch for
noise on the scope display, and advance R41 slightly farther, if necessary, until the
signal level remains at about 0 V.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-13
Putting Things Back Together
1. Restore the transceiver’s time-out timer to the original value (if changed) using the
PTOT_XXX command on the HHT. The factory default setting is 180 seconds.
2. Reinstall the cover. Reconnect the antenna feedline and reconnect the RTU’s
interface cables to the transceiver.
3. Confirm that the unit operates normally with the associated RTU.
4. Secure all cables, providing strain relief if necessary, and check connectors for
tightness.
This completes the set-up of the transceiver with a 1200 baud modem installed. For
additional information on the 1200 baud modem refer to Appendix A.
TEST PROCEDURE ➍:
TRANSMIT FREQUENCY, SQUELCH, DEVIATION,
AND RECEIVE AUDIO OUTPUT—For Radios with MDS’s Internal 4800 BPS Modem
In the following procedures, references to SW1 & SW2 relate to the switches of the Data
Terminal Emulator (Figure 4-2). See Figure 4-5 for an assembly drawing of the 4800 baud
Modem. See Figure 4-9 for the locations of adjustable controls on the transceiver
motherboard.
Set-up
1. Remove the cover from the transceiver by loosening the four captive cover screws
and lifting it straight up. Make a list of the settings of configuration switch S1 on the
modem—they will be changed temporarily during the alignment procedure.
2. Close the Diagnostics Channel and disconnect the HHT.
3. Connect the Data Terminal Emulator to the INTERFACE connector.
4. Connect the transceiver’s ANTENNA connector to the input of the service monitor
using a short length of RG-8/U or RG-214 coaxial cable. Set up the service monitor
to monitor the transmitter’s center (channel) frequency.
5. Set the transmitter deviation to minimum by rotating R168, Deviation, fully counter
clockwise.
6. On the modem, set S1 to positions 2 and 4 ON (Closed), all others OFF (Open).
Transmit Frequency
1. Key the transmitter by raising RTS (SW1 Closed). The TXD line should be at logic
low (LED annunciator TD [TXD] off).
2. Check for correct transmit center frequency. With TXD low (SW2 Open) the
transmitted frequency should be within 100 Hz of the assigned center frequency. If
necessary, adjust the TX Frequency Adjustment control on the TCXO.
R
M
4-14
If Remote Maintenance is installed, use the IF / DF / INCF / DECF commands
instead of the adjustment on the TCXO. The IF / DF commands
increment/decrement the frequency in single steps while the INCF / DECF
commands make larger jumps by adding a space and a number to the
command. (For example: INCF_8 to increase the frequency by eight steps out
of 100.) When finished, type RMST to store the setting.
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
Data Deviation
1. With the transmitter still keyed (SW1 Closed), increase the deviation by rotating
R168 clockwise to cause the frequency to shift down from the assigned center
frequency by 1.6 kHz ± 75 Hz.
If Remote Maintenance is installed, set R168 to its full-clockwise position
and use the ID / DD / INCD / DECD commands to set the downward frequency
shift to 1.6 kHz. The ID / DD commands increment/decrement the deviation
in single steps while the INCD / DECD commands make larger jumps by
adding a space and a number to the command. (Example: INCD_4 to increase
the deviation by four steps out of 100.) When finished, type RMST to store
the setting.
Set the TXD line high (SW2 Closed). Observe the carrier frequency shifting up 1.6
kHz ± 75 Hz from the assigned center frequency. If it does not, alternately adjust the
TX Frequency adjustment on the TCXO and R168, checking both high and low
frequencies for equal 1.6 kHz shifts.
Note—There is some interaction between R168 and the TX Frequency adjustment on
the TCXO. If the shift is equal in both directions, but exceeds 1.6 kHz, it may be
necessary to turn the deviation down slightly and repeat this step. Continue to
alternately adjust R168 and the TX Frequency adjustment on the TCXO until equal
1.6 kHz shifts are obtained.
Set RTS and TXD low (SW1 and SW2 Open).
Set S1-3 on the modem to ON. This generates a data test pattern of 101010.
Set RTS high (SW1 Closed).
R
M
2.
3.
4.
5.
S1
CONFIGURATION
8
1
OFF (OPEN)
U3
Pin 3
ON
(CLOSED)
U6
U5
P8
P6
Figure 4-5. 4800 BPS FSK Modem; MDS P/N 03-1831A01
See Table B-1 in Appendix B for details on switch settings.
6.
7.
8.
9.
Adjust the HF Audio Compensation control, R179, if necessary, to produce 2.7 kHz
±75 Hz deviation as measured on the service monitor.
Set RTS low (SW1 Open) and turn OFF S1-3 on the modem.
Set the service monitor to generate a –60 dBm (225 µV) on-channel signal with a
1 kHz tone at 2.5 kHz deviation.
Connect an oscilloscope set to a 5 ms timebase to U3 Pin 3 on the modem. Adjust
R25 (Receive Audio Level) on the transceiver’s motherboard for a waveform
showing a 0.7 to 0.75 Vp-p sinewave riding on 2.5 Vdc.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-15
Squelch Adjustment
1. Using an oscilloscope set for DC coupling and 2 V or 5 V per division, observe the
Receiver Unsquelched (RUS) signal at Pin 10 of the radio’s INTERFACE connector.
2. Insert an on-channel signal at –120 dBm (.225µV), with a 1 kHz tone and 2.5 kHz
deviation. Adjust R41, Squelch Threshold, fully counterclockwise while observing
the oscilloscope display.
3. Set the squelch to be fully closed at this signal level by advancing R41 until the
oscilloscope pattern changes from about 8 V to 0 V. Watch for noise on the scope
display, and advance R41 slightly farther, if necessary, until the signal level remains
at about 0 V.
Putting Things Back Together
1. Restore the transceiver’s time-out timer duration to the original value (if changed)
using the PTOT_XXX command on the HHT.
2. Restore the modem’s Configuration Switch, S1, to its original settings or as
recommended in Table B-1 of Appendix B of this manual.
3. Reconnect the RTU’s interface cables to the transceiver and reinstall the cover.
Reconnect the antenna feedline.
4. Confirm that the unit operates normally with the associated RTU. Secure all cables,
providing strain relief if necessary, and check connectors for tightness.
This completes the set-up of the transceiver with a 4800 baud modem installed. For
additional information on the 4800 baud modem refer to Appendix B.
TEST PROCEDURE ➎:
TRANSMIT FREQUENCY, SQUELCH, DEVIATION,
AND RECEIVE AUDIO OUTPUT—For Units with MDS’s Internal 9600 BPS Modem
In the following procedures, references to SW1 & SW2 relate to the switches of the Data
Terminal Emulator (Figure 4-2). See Figure 4-6 for an assembly drawing of the 9600 baud
Modem. See Figure 4-9 for the locations of adjustable controls on the transceiver
motherboard.
Set-up
1. Remove the cover from the transceiver by loosening the four captive cover screws
and lifting it straight up. Make a list of the settings of configuration switch S1 on the
modem—they will be changed temporarily during the alignment procedure.
2. Close the Diagnostics Channel and disconnect the HHT.
3. Connect the Data Terminal Emulator to the INTERFACE connector.
4. Connect the transceiver’s ANTENNA connector to the input of the service monitor
using a short length of RG-8/U or RG-214 coaxial cable. Set up the service monitor
to monitor the transmitter’s center (channel) frequency.
5. Set the transmitter deviation to minimum by rotating R168, Deviation, fully counter
clockwise.
6. On the modem, set S1 to 6 & 7 ON (Closed), all others OFF (Open).
4-16
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
S1
CONFIGURATION
8
1
OFF (OPEN)
U3
ON
(CLOSED)
Pin 7
U6
U5
P8
P6
Figure 4-6. 9600 BPS FSK Modem; MDS P/N 03-1833A01
See Table C-1 in Appendix C for details on switch settings.
Transmit Frequency
1. Key the transmitter by raising RTS (SW1 Closed). The TXD line should be at logic
low (LED annunciator TD [TXD] off).
2. Check for correct transmit center frequency. With TXD low (SW2 Open) the
transmitted frequency should be within 100 Hz of the assigned center frequency. If
necessary, adjust the TCXO frequency adjustment (on the transceiver’s
motherboard), to place it on frequency.
R
M
If Remote Maintenance is installed, use the IF / DF / INCF / DECF commands
instead of adjusting the TX Frequency adjustment on the TCXO. The IF / DF
commands increment/decrement the frequency in single steps while the
INCF / DECF commands make larger jumps by adding a space and a number
to the command. (For example: INCF_8 to increase the frequency by eight
steps out of 100.) When finished, type RMST to store the setting.
Data Deviation
1. With the radio still keyed (SW1 Closed), raise TXD (SW2 Closed). This should
cause the transmitted frequency to shift by 1.6 kHz ±75 Hz either up or down.
It does not matter if the frequency shifts up or down; the way it shifts depends only
upon the phase of the modem’s internal 9600 Hz clock at the instant the TXD line
changed. If the TXD line is toggled, the transmit frequency should change between
the assigned center frequency when TXD is low and 1.6 kHz on either side of center
when TXD is high. If necessary, adjust R168 on the transceiver motherboard to
obtain a 1.6 kHz ±75 Hz shift.
If Remote Maintenance is installed, set R168 to its full-clockwise position
and use the ID / DD / INCD / DECD commands to set the frequency shift to
1.6 kHz. The ID / DD commands increment/decrement the deviation in single
steps while the INCD / DECD commands make larger jumps by adding a space
and a number to the command. (Example: INCD_4 to increase the deviation
by four steps out of 100.) When finished, type RMST to store the setting.
2. Toggle TXD high (SW2 Closed) until the frequency shifts opposite from above. The
frequency should shift 1.6 kHz ±75 Hz. If not, alternately adjust the TX Frequency
adjustment on the TCXO and R168 on the transceiver’s motherboard, toggling TXD,
checking both the high and low frequencies for equal 1.6 kHz shifts.
Continued on next page.
R
M
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-17
Data Deviation (Continued)
Note—There is some interaction between R168 and the TX Frequency adjustment on
the TCXO. If the shift is equal in both directions, but exceeds 1.6 kHz, it may be
necessary to turn the deviation down slightly and repeat this step. Continue to
alternately adjust R168 and the TX Frequency adjustment on the TCXO until equal
1.6 kHz shifts are obtained.
3. With the high and low shifts equal, set TXD low (SW2 Open). The transmit
frequency should be within ± 200 Hz of the assigned (channel) frequency. If not,
adjust the TX Frequency adjustment on the TCXO as described in the Transmit
Frequency procedure above.
4. Set RTS high (SW1 Closed) and turn ON S1-3 on the modem.
5. Adjust the Transmitter HF Audio Compensation control, R179, if necessary, to
produce 2.7 kHz ± 75 Hz deviation as measured on the service monitor.
6. Unkey the radio by setting RTS low (SW1 OPEN).
7. Turn OFF S1-3 on the modem.
Receive Audio Output Adjustment
1. Generate a –60 dBm (225 µV) signal on the receive frequency with 1 kHz
modulation at 2.5 kHz deviation.
2. Using an oscilloscope set to a 5 ms timebase, observe the waveform at U3 Pin 7 on
the modem board; it should be a 0.7 to 0.75 Vp-p sinewave riding on 2.5 Vdc. If not,
adjust the Receive Audio Level control, R25 (on the transceiver’s motherboard), to
produce 0.7 to 0.75 Vp-p at TP1.
Squelch Adjustment
1. Using an oscilloscope set for DC coupling and 2 V or 5 V per division, observe the
Receiver Unsquelched (RUS) signal at Pin 10 of the INTERFACE connector.
2. Insert an on-channel signal at –120 dBm (.225 µV), with a 1 kHz tone and 2.5 kHz
deviation. Adjust R41, Squelch Threshold, fully counterclockwise while observing
the oscilloscope display.
3. Set the squelch to be fully closed at this signal level by advancing R41 until the
oscilloscope pattern changes from about 8 V to 0 V. Watch for noise on the scope
display, and advance R41 slightly farther, if necessary, until the signal level remains
at about 0 V.
Putting Things Back Together
1. Restore the transceiver’s time-out timer duration to the original value (if changed)
using the PTOT_XXX command on the HHT.
2. Restore the modem’s Configuration Switch, S1, to its original settings or as
recommended in Table C-1 of Appendix C.
3. Reconnect the RTU’s interface cables to the transceiver and reinstall the cover.
Reconnect the antenna feedline.
4. Confirm that the unit operates normally with the associated RTU. Secure all cables,
providing strain relief if necessary, and check connectors for tightness.
This completes the set-up of the transceiver with a 9600 baud modem installed. For
additional information on the 9600 baud modem refer to Appendix C in this manual.
4-18
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
TEST PROCEDURE ➏:
REMOTE MAINTENANCE MODULE—
Loopback Code Programming, Mode Selection, Calibration & Testing
Introduction
The Remote Maintenance Module (Figure 4-7) is a small PC board assembly that mounts
vertically into Jacks J5 and J7 of the transceiver PC board. The module contains two
adjustable controls—Loopback TX Audio Level (R6), and Temperature Setting (R33).
Normally, R6 needs adjustment only when the module is first installed in the radio. R33 is
adjusted at the factory.
The following procedures are not required for units shipped from the factory with Remote
Maintenance installed. Perform these procedures only if the Remote Maintenance Module is
being newly installed, is known to be out of adjustment, or if the Remote Maintenance
Module is being replaced.
NOTE
If you are unsure whether a Remote Maintenance Module is
installed in the transceiver, open the Diagnostics Channel with
the Hand-Held Terminal and enter the STAT command. The
display responds with the type of diagnostics that are installed
in the transceiver. The forth character will show an I if the
module is installed, or a U if it is not installed. (See Table 3-2 to
interpret the full response.)
R6
LOOPBACK TX
AUDIO LEVEL
R33
TEMP. SET
J7
J5
Figure 4-7. Remote Maintenance Module (P/N 03-1958A01)
NOTE
In a properly aligned system, Remote Maintenance provides
valuable information to service personnel, however, it is not a
substitute for calibrated test equipment.
Loopback Code Identification
A loopback code is used to identify the radio during diagnostics operations. Each radio in the
system must have a unique four digit numerical loopback code for Remote Maintenance
diagnostics to work properly. The code should be one that is not being used elsewhere in the
system in which the radio will be installed; duplicate codes can cause failure in or incorrect
data from radios having the same loopback codes.
To determine the current loopback code, connect the HHT to the radio and open the
Diagnostics Channel. Next, type LBC. The radio responds by displaying the code on the HHT
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-19
display. (Units shipped from the factory are pre-programmed with a default loopback code
consisting of the last four digits of the radio’s serial number.)
The displayed loopback code is followed by the characters UI (uninstalled) or I (installed) at
the end of the second line in the display to indicate the presence of a Remote Maintenance
Module. If no loopback code has been entered, the indication will be UI for uninstalled, even
if the module is present, since a valid loopback code has not been entered. When the
loopback code is entered, and the radio is shut down and re-powered up, the indicator will be
I for installed.
Programming a New Loopback Code
If you wish to program a new loopback code, type PLBC_XXXX, where the underline character,
“_”, is a space and “XXXX” is a four digit address code. This code identifies the unit during
diagnostic polling by the master station. Note—the code must contain four digits and no
letters. After the new loopback code has been entered, the radio responds by displaying the
code on the HHT display.
Diagnostics Mode Selection
The Remote Maintenance Module can be set for one of three levels (modes) of diagnostics
and control. The MODE command is used to set the diagnostics and control mode. Review
Table 3-1—Diagnostics and Control Capabilities for detailed descriptions of the three
operating modes. MODE_3xxxx is used to invoke Remote Maintenance, the highest level of
diagnostics. Since it provides the highest level of diagnostics and control, many users prefer
to keep the radio set up for Remote Maintenance.
Diagnostics Deviation Adjustment
1. Loosen the four cover screws and remove the top cover from the transceiver by
lifting straight up.
2. Connect the transceiver’s ANTENNA connector to the input of the service monitor
using a short length of RG-8/U or RG-214 coaxial cable.
3. Set the service monitor to receive at the transceiver’s transmit frequency.
4. Connect the transceiver’s power cord and apply power.
5. With the Hand-Held Terminal (HHT) connected to the INTERFACE connector, open
the Diagnostics Channel using the OPEN command.
6. If Remote Maintenance is not already enabled, type MODE 3 xxxx, where xxxx is the
speed in bits per second (i.e., 1200, 4800 or 9600 bps) of the internal data modem
plugged into Jacks J6 and J8. If the radio is not equipped with an internal MDS
modem, use MODE 3 1200.
7. Type TEST_1 to activate a DTMF test tone and key the transmitter.
8. Measure the transmitter deviation on the service monitor. If the deviation is not
2.5 kHz, adjust it to 2.5 kHz using R6, TX Audio, on the Remote Maintenance
Module. (See Figure 4-6.)
9. Type TEST_2 to disable the test tone and unkey the transmitter.
Temperature Calibration
The Remote Maintenance Module has a built-in temperature sensor used to measure the radio’s internal temperature during operation. The temperature sensor has been calibrated at the
4-20
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
factory and the need for field adjustment of this parameter is rare. Nevertheless, instructions
are given below. If the temperature calibration is misadjusted, its value in remote (over-theair) and local diagnostics will be compromised.
1.
2.
3.
4.
5.
Measure the temperature at or near the transceiver chassis using a thermometer that
is accurate to 1°C. The transceiver must be at room temperature.
Use the TEMP command to obtain the temperature reading for the radio. The reading
is in degrees Celsius.
If there is a difference between the thermometer reading and the TEMP indication,
adjust potentiometer R33, TEMP SET, on the Remote Maintenance Board to obtain a
match between the measurements taken on the HHT and those taken with the
thermometer. (See Figure 4-7.) The measurement given by the HHT is updated once
per second. That is, the TEMP command does not have to be invoked after each
adjustment of R33.
Close the Diagnostics Channel to the transceiver. and disconnect the HHT.
Reinstall the cover on the transceiver.
Forward Power & RSSI Calibration
If a Remote Maintenance Module is added to a transceiver as a field upgrade, or a module is
transferred from one radio to another, two diagnostic measurements need calibration for
maximum accuracy. These are the forward power (FPWR) and received signal strength (RSSI)
functions.
Procedure
1. Connect a 50 Ω dummy load through a directional wattmeter to the ANTENNA
connector of the transceiver.
2. Connect the HHT to the INTERFACE connector of the transceiver.
3.
Key the transmitter with the KEY command from the HHT. Type KEY +
4.
Set the transmit power output to 5 watts using the TX Power Output level control,
R69, on the transceiver motherboard as indicated on the in-line directional
wattmeter.
5.
Enter the calibrate power command, CPWR, from the HHT. Type CPWR +
forward and reflected power detectors will be automatically calibrated.
6.
Dekey the transmitter with the DKEY command from the HHT. Type DKEY +
ENTER
.
ENTER
. The
ENTER
.
Disconnect the directional wattmeter and dummy load from the ANTENNA connector.
Connect a communications service monitor to the ANTENNA connector.
Inject an on-channel unmodulated –110 dBm (.710 µV) signal.
Enter the calibrate received signal strength low level command, RSSL, from the HHT.
Type RSSL + ENTER . The low level RSSI calibration point is automatically
calibrated.
11. Increase the signal level to –60 dBm (225 µV) signal.
7.
8.
9.
10.
12. Enter the calibrate received signal strength high level command, RSSH, from the
HHT. Type RSSH + ENTER . The high level RSSI calibration point will be
automatically calibrated.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-21
13. Enter the received signal strength command, RSSI, from the HHT. Type RSSI +
ENTER . The display shows the current received signal level in dBm. Check the
calibration with the communications service monitor set between –60 dBm (225 µV)
and –120 dBm (.225 µV).
14. This completes the calibration procedure. Disconnect the HHT and communications
service monitor.
Testing The Remote Transceiver With The Master Station—Optional Checkout
This section provides abbreviated instructions for testing Remote Maintenance with a
properly equipped Master station on a service bench. This test simulates over-the-air Remote
Maintenance using a PC and MDS 2000 Diagnostics and Control System software. Complete
instructions for using the software are contained in the MDS 2000 Diagnostics and Control
System software User’s Guide (P/N 05-1919A01).
1. Connect the transceiver to the Master Station using coaxial cable through at least
100 dB of attenuation. The attenuators at each end of the connection should be rated
to continuously withstand at least 5 watts of RF power.
2. Attach the PC through one of its serial ports to the DIAGNOSTIC connector on the rear
of the MDS 2100 Master Station.
3. Set the Master Station’s rear-panel DTE/DCE switch to DCE if you’re using a
straight-through serial cable, or DTE if you’re using a null-modem cable.
4. Load the MDS 2000 Diagnostics and Control System software on the PC and open
the Diagnostics Channel to the Master Station.
5. Using the software’s Equipment List Editor, select the Remote transceiver to be
tested and set the radio’s diagnostic level to Remote Maintenance.
6. Return to the polling screen and verify that you can perform a diagnostic poll on the
remote radio.
7.
8.
9.
Press F4 to invoke Remote Maintenance. The Remote Maintenance screen for that
transceiver appears. (See Figure 4-8.)
The software displays the Remote radio’s transmit frequency error compared to the
master station’s receive frequency. The offset (or difference) should be within 0.3
kHz; If not, adjust the MDS 4310 transmit frequency as described in the Field
Alignment instructions in this chapter.
Verify that the DTMF deviation display indicates approximately 2.5 kHz. If no
modem is installed in the transceiver, skip ahead to Step 11. Otherwise, proceed with
Step 10.
10. Press F3 to toggle the deviation display from DTMF to DATA. If the data deviation
is 2.7 kHz ±0.2 kHz, proceed to the next step. If not, adjust the MDS 4310 deviation
as described in the Field Alignment instructions in this chapter.
11. If the power output is not set to the desired output level (usually 5 watts), use the
← → arrow keys to select the POWER bar and the ↑ ↓ arrow keys to increase or
decrease the output level as desired. The POWER bar also shows the reflected power
level and includes a VSWR summary—OK, CHECK SYS, or BAD.
12. Press F4 to store the changes within the Remote Maintenance Module.
13. Press Esc to close Remote Maintenance of that Remote unit and return to the
previous screen.
4-22
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
14. This completes the Remote Maintenance checkout procedure. For additional
information on the Remote Maintenance Module refer to Appendix D.
MICROWAVE DATA SYSTEMS -- REMOTE MAINTENANCE
ADJUSTMENT
Press (Esc) to Exit or Use (Arrow) keys to select and change a Control Setting
[F2] Update Screen [F4] Store Changes
[F3] Toggle DTMF/DATA Deviation Display
--- REMOTE CONTROL SETTINGS -POWER
FREQ
[F6] AFC Off [F7] Rx AFC [F8] Tx/Rx AFC
DATA DEV.
[ 56 ]
40
AFC is currently set to (OFF)
65
--- MASTER MONITORING OF ---- REMOTE UNIT (8802) --SUPPLY
POWER (W)
SIGNAL
FREQ
DATA
VOLTAGE REF / FWD / VSWR
STRENGTH OFFSET DEVIATION
13.9V
0.3 / 4.8 / OK
–59dBm
0.3KHz
2.6KHz
16
9.0
–50
+6.0
6.0
15
7.5
–60
+4.0
5.0
14
6.0
–70
+2.0
4.0
13
4.5
–80
0
3.0
12
3.0
–2.0
2.0
11
1.5
–4.0
1.0
10
0
–90
REMOTE UNIT
TEMPERATURE –100
+25.0°C
–110
–6.0
0
STATUS
Figure 4-8. Remote Maintenance Screen
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-23
This page intentionally blank
4-24
FIELD TESTS & ADJUSTMENTS
MDS 05-2415A01, Rev. A
OPTION BOARD 1
J6 & J8
R25
RECEIVE
AUDIO LEVEL
J16
FULL DUPLEX
INTERFACE
J14
RX AUDIO
NORMAL/INVERT
J6
J8
J7
J1
EXTERNAL
INTERFACE
DISABLE
RS-232
J5
2
4
1
3
T1
ENABLE
LED
J11
SHUNT AS
REQUIRED
OPTION BOARD 2
J5 & J7
TX FREQ.
NORM
INV.
R168
TX DEV.
L25
LED
INDICATORS
L8
Z1
Z2
R179
HF AUDIO
COMP.
J2
DC POWER
INPUT
C247
VCO RANGE
(THRU SIDE
OF SHIELD)
F1
4A FUSE
R41
SQUELCH
THRESHOLD
J4
ANTENNA
R69
TX POWER
OUTPUT
Figure 4-9
MDS 4310 Transceiver 2314Axx PC Board
Test Points and Adjustments
Potentiometer types may differ from those shown.
MDS 05-2415A01, Rev. A
FIELD TESTS & ADJUSTMENTS
4-25/26
CHAPTER 5—THEORY OF
OPERATION
For the following discussion, see Figure 5-1, the radio’s block diagram at the end of this
chapter.
RECEIVE FRONT END
Connector J4 on the main PC board conducts the RF signal from the front panel ANTENNA
connector to the antenna switch network. In the receive mode, one port of the antenna switch
conducts the receive signal to the input of helical filter Z1.
The output of Z1 is fed to RF amplifier Q1. The output of Q1 goes to helical filter Z2. The
output of Z2 goes to M1, a double-balanced mixer whose local oscillator injection signal is
derived from the VCO output.
HIGH IF
The 45 MHz High IF signal from M1 enters the IF amplifier. The output of IF amplifier
connects to L25 as an input matching transformer. The receive signal is then passed to FL1A
and FL1B. FL1A and FL1B are components of a 4-pole crystal filter that provides some of
the IF selectivity of the receiver. The output of FL1B is conducted to U32, which contains
the low IF amplifier and other functions.
LOW IF
U32 contains several circuit sections: mixer, oscillator, IF amplifier/limiter, quadrature detector and received signal strength indication driver. The second 44.55 MHz LO for U32 is
derived from the TCXO. A frequency tripling circuit multiplies the 14.85 MHz TCXO signal
and triples it up to 44.55 MHz. This is consequently mixed with the 45 MHz IF to form the
450 kHz IF.
The 450 kHz output of the second mixer is fed to a ceramic filter set consisting of FL2 and
FL3. This filter set provides the main adjacent channel selectivity of the receiver.
The output of FL3 is fed to the limiter amplifier input pin of U32. The limiter output is fed to
a quadrature detector circuit tuned by discriminator coil T1; recovered audio is passed to
U3A audio buffer.
A secondary output of the IF subsystem of U32 gives a received signal strength indication
(RSSI) voltage. The RSSI signal is used by the remote maintenance module and is available
at the INTERFACE connector J1-21 through a buffer and scaler, U3C.
RECEIVE AUDIO
The unfiltered recovered audio from the IF discriminator passes through amplifiers U3A,
U3B and configuration jumper J14.
MDS 05-2415A01, Rev. A
5-1
The output of the squelch gate goes to the modem receive audio amplifier, U5A. U5A is an
amplifier with the gain set by potentiometer R25. R25 is used to adjust the receive audio
level supplied to the modem and remote maintenance boards.
U5D and U5C are an audio lowpass filter that removes noise from the receive audio. The
output of this filter goes to external modems through J1.
SQUELCH
The squelch circuit consists of a high-pass filter, noise amplifier, noise rectifier and a
comparator.
The high pass filter U6A removes low frequencies of the detected IF output. The output of
U6A goes to a gain stage, U6B, which amplifies the high frequency noise. The gain of U6B
is set by R41, which is the squelch threshold adjustment.
The amplified high frequency noise output from U6B goes to a full-wave rectifier, which
compares this DC voltage with a fixed reference voltage. U6C, which rectifies the noise
signal. The output of this stage goes to a squelch comparator, U6D whose output is the
receiver unsquelch sensor (RUS) line, and is used to control squelch gate U26A in the receive
audio path. This gate is also controlled by the RX MUTE signal from U19D.
The RUS logic signal is also fed to the modem and is used to gate the DCD output from the
modem. In addition, this signal appears at J1 pin 10 through a 1 kΩ resistor.
POWER SUPPLY
The + 13 volt DC input appears when an external power source is connected to J2. From J2,
the + 13V is conducted to the internal transceiver circuits through F1, a 4 ampere fuse. The
fuse protects the transceiver in the event the external, in-line fuse is either defeated or
replaced with one of a higher rating.
Z4 is a EMI power line filter. C77 is a electrolytic capacitor. These two devices help provide
a noise free power source for the transceiver circuits. A 17 volt zener diode across C77
provides over-voltage and reverse polarity protection.
U38 provides a regulated + 8 volts for most transceiver circuits. U13 provides a regulated + 5
volts, which supplies power to the microcontroller and the logic circuitry.
U45 is a low voltage protection device. It will disable the radio when the input voltage
becomes less than 10 volts. The output from U45 drives the radio disable circuit Q15 which
disables the 8 volt and 5 volt regulators, U38 and U13.
A precision reference DC voltage of + 2.5V is supplied by U4; this is used by the FSK
modem circuitry.
The RX/TX signal from the microcontroller applies + 8 volts to the RF amplifier, high IF
amplifier and tripler circuit in the receive mode, and is shut off in the transmit mode.
Q19 supplies a biasing signal to the transmitter amplifiers and antenna switch. Q19 is turned
on during transmit by the microcontroller.
The main transmit power control signal from the microcontroller, TXE2, is first conditioned
by U46 whose output is sent to the power control potentiometer R69. The wiper of R69 is
connected to U44B which is a power-leveling circuit. U44B drives U44A, Q41 and Q43
which form an adjustable voltage regulator. The output of this regulator feeds the power
control pin on U33
5-2
THEORY OF OPERATION
MDS 05-2415A01, Rev. A
The transmitter can be turned off, independent of microcontroller control, by the synthesizer
out-of-lock signal. An out-of-lock condition at the synthesizer will bring the O/L line high,
overriding the power control signal TXE2.
TRANSMIT POWER AMPLIFIER
The power amplifier chain of the transmitter section consists of U40 and U33. U40 is a
driving amplifier for U33. The output of U40 is fed to hybrid power module U33. The power
control of U33 is controlled by the power control regulator Q3 and U44A.
The RF output of U33 is fed through a directional coupler to the antenna switching network.
ANTENNA SWITCH
The antenna switch consists of PIN diodes and a filter network. In the receive mode, PIN
diodes are unbiased and effectively disconnected from the circuit. Under this circumstance,
the received signal is free to pass to the input of helical resonator Z1 through a low pass
filter.
During the transmit mode, the PIN diodes are biased ON by the Q19. When the diodes are
conducting, one diode provides a low impedance path for the transmit signal to the ANTENNA
connector and the other diode shorts out the capacitor in the switching circuit. With the
capacitor shorted, the filter network is equivalent to a quarter wave transmission line with no
RF current flowing through the inductor.
DIRECTIONAL COUPLER
The directional coupler is used during diagnostic measurements of forward and reflected
power at the ANTENNA connector. The directional coupler consists of an in-line transmission
line section that conducts RF energy from power amplifier U33 to the antenna switch.
Coupled line sections located immediately adjacent to, and either side of the transmission
line, receive a sample of the RF energy passing through the coupler. Rectifiers mounted on
each end of coupled line sections produce DC voltages. These DC voltages are proportional
to the power levels appearing on the coupled lines.
The directional coupler provides a forward power measurement that can be displayed through
local diagnostics when the radio has the Remote Maintenance Module installed.
KEYLINE AND CONTROL CIRCUITS
There are three push-to-talk (PTT) inputs to the keyline control circuit. Three negative inputs
and one positive going input. The negative going inputs come from J1-16, the modem, and
the audio processing board. These are inverted and added to the positive going input coming
from J1 pin 14. This signal drives the keyline inverter U19A.
RADIO DISABLE
J1-Pin 12, is the input to the radio disable circuit. The radio disable circuit minimizes power
consumption by shutting off all of the transceiver circuits except for Q15 and CR32B. This
allows the user to inhibit transceiver functions with an open-collector interface circuit.
J1-Pin 12 should be left open to permit the transceiver to function normally.
MDS 05-2415A01, Rev. A
THEORY OF OPERATION
5-3
If J1-Pin 12 is grounded U13 and U38 are disabled. Since U38 supplies current to nearly all
of the transceiver circuits, current consumption in the transceiver is reduced essentially to
zero. This eliminates the need to externally switch the +13 volts applied to the transceiver.
AUDIO/DATA MODULATION INPUT SWITCHING
One section of U15, switch U15X, controls data appearing at the RXD terminal, Pin 3 of J1,
switching between modem data and microcontroller data from U16. Another section, U15Z,
switches the transmit audio path between the modem transmit audio output and the external
transmit audio input to the transceiver from J1.
U15Z is controlled by means of a modem enable line which is tied to +10 volts when the
modem option is installed.
Without the modem installed, the normal state of U15Z is such that transmit audio from J1
Pin 9 modulates the transmitter. With the modem installed, the external transmit audio from
J1 is cut off, and modem transmit audio is selected.
Should the positive-going push-to-talk (PTT) input on J1-14 be driven high (to key the
transmitter—such as when the external order wire option is used), U19B pulls the control line
for U15Z low. This allows external transmit audio in from J1 to modulate the transmitter, and
cuts off any audio coming from the modem.
MICROCONTROLLER/EEPROM
The microcontroller, U16, controls many of the on-board functions of the transceiver. Some
of the control functions are:
• Frequency Programming and Control of the Synthesizer
• Modem RTS/CTS Delay
• Transmitter Time-out Timer
• Transmit Soft Carrier Dekey Delay
• Transmit Squelch Tail Eliminator Delay
• Loopback/Diagnostic Functions
U16 runs a predetermined routine that controls its functions; this routine is permanently
programmed within the IC and cannot be altered. All programmable functions and values are
stored by the microcontroller in an electrically erasable, programmable, read-only memory
(EEPROM) IC, U18. These include operating parameters such as frequency, time-out timer
limits, soft carrier dekey times, and CTS delay time, as well as model and factory serial
numbers. U16 and U18 share a common clock and exchange data through data lines.
The microcontroller can be reset by several different means. An error output from U13 drives
the reset line low causing the microcontroller to reset or the internal modem can drive the
reset line from J8. The error signal from U13 resets U16 allowing a stable initialization when
13 Vdc is first applied to the transceiver.
The inhibit line on U13 is controlled indirectly by the radio enable line available at J1-12.
The inhibit line on U13 will force a microcontroller reset through the error output line.
5-4
THEORY OF OPERATION
MDS 05-2415A01, Rev. A
DIAGNOSTICS DATA CONTROL
Communications between the microcontroller U16 and an external terminal, PC or the HHT
is accomplished by means of the TXD (J1–Pin 2) and RXD (J1–Pin 3).
U16 constantly monitors transmit data input on J1–Pin 2, and ignores all data unless the
OPEN command from the external programmer is detected or a ground is detected on J1–Pin
23. The receive data output on J1–Pin 3 is normally connected to the output of the modem
demodulator when a modem is used. When the OPEN command is detected, U16 switches
the receive data path from the modem to its own data output port in order to allow it to
communicate directly with the terminal.
The receive data control pin of U16 controls the normally high base of Q8. When the
diagnostic channel is opened, Q8 is turned off, thus switching the state of gate U15X. This
allows data from the microcontroller to appear at the RXD output (J1-Pin 3).
TRANSMIT AUDIO
The transmit audio circuit consists of a variable gain amplifier, active low-pass filter, and a
summing amplifier. The variable gain amplifier U28C gain is set by R168. The transmit
audio then passes through a low pass filter consisting of U28B and associated components.
The output of U28B, and transmit audio from the remote maintenance board, are summed
together in amplifier U28D.
Transmit audio is also fed to the VCO input by means of a R179, which is the high frequency
(HF) compensation control. This control provides a balanced transmit audio frequency
response.
PLL/SYNTHESIZER
The temperature compensated 14.85 MHz crystal oscillator (TCXO) generates the reference
frequency for the phase-lock loop (PLL) circuit.
U36 is a CMOS PLL synthesizer consisting of a phase detector, a programmable reference
divider, a programmable feedback divider, and prescaler. Data input is serially loaded from
U16; this data consists of binary coded numbers representing the reference and feedback
(VCO RF sample) divider ratios required to produce the final transmit frequency. The
reference divider is programmed only on power-up, with a power reset or with a PLL
out-of-lock condition. The feedback divider value changes according to the transmit/receive
frequencies entered by the PTX and PRX commands, and is reloaded from the EEPROM every
time a transmit-to-receive or receive-to-transmit transition occurs.
The phase detector output of U36 is fed to the VCO tuning input through an R-C loop filter.
A sample of transmit audio modulation of the VCO is fed to the loop filter from the wiper of
R179.
The lock detector output of U36 is applied to U28A. When the PLL is in lock, U36 shuts off
U28A and keeps the O/L line low. An out-of-lock condition causes U28 to drive the O/L line
high. The O/L line inhibits the transmit regulator, as previously described in the POWER
SUPPLY section; also, it is conducted to J1-Pin 25, through a 1 kΩ resistor.
RS-232 DATA INTERFACE
U31 is an RS-232 line driver/receiver integrated circuit with an input/output disable function.
It has an internal +5 volts to ±10 volt converter that allows it to provide an RS-232
MDS 05-2415A01, Rev. A
THEORY OF OPERATION
5-5
compatible output. Transient protection for the five RS-232 I/O lines from J1 is
accomplished by means of zener protection diodes. Static discharge or over-voltage condition
appearing on J1 will be shunted to ground with these devices before reaching U31.
In the data signal interface between the plug-in modem assembly and the main transceiver
board (i.e., the plug in modem option), the signals are inverted from standard RS-232 signal
polarity. The inverted signals, namely RXD(L), TXD(L), DCD(L), RTS(L), and CTS(L), are
fed directly to U31.
Header J11 allows the TTL option to be selected. When the pins 1 and 2 of J11 are connected
together, U31 is disabled. This effectively removes U31 from the circuit.
LED INDICATORS
U29 and U5 drive the LEDs. U29 is a non-inverting buffer. A jumper across J11, pins 3 and 4
is required to enable the LEDs.
PWR
This LED, CR31B, is illuminated if more than 10 volts is applied to the radio. It flashes if
the VCO is Out-of-Lock. U5B is a flasher circuit.
RTS
This LED, CR31A, is illuminated if any of the Push-To-Talk lines is active.
TX
This LED, CR32B, is illuminated if the transmitter power control is active.
TXD
This LED, CR32A, is illuminated if the RS-232 transmit data line is low.
CD
This LED, CR33B, is illuminated if the receiver detects a carrier strong enough to break
squelch.
RXD
This LED, CR33A, is illuminated if the RS-232 receive data line is low.
5-6
THEORY OF OPERATION
MDS 05-2415A01, Rev. A
Figure 5-1.MDS 4310 Transceiver Block Diagram
THEORY OF OPERATION
MODEM TX AUDIO
(J6-24)
TX AUDIO INPUT
(J1-9)
MODEM ENABLE
(J6-18)
PTT
(J1-16)
MODEM PTT
(J6-9)
PTT
(J1-14)
RADIO
ENABLE
(J1-12)
FWD PWR
(J712)
REFL PWR
(J73)
J4
ANTENNA
CONNECTOR
J
2
+13.5 V
IN
F1
4A
U15Z
DIRECTIONAL COUPLER
ANTENNA SWITCH
Z1
Z
4
U19
B
U19
A
R69
POWER
ADJUS
T
L3
3
U33
U26
B
U19
F
U13
U4
C7
7
5
VDC
L3
2
2.5
VDC
Q3
U44
A
XMI
T
HYBRID
POWER
MODUL
E
Q1
RX
RF
AMP
U3
8
8
VDC
U40
U28C
R168
TRANSMIT DEV ADJ
Z2
U28B
LP
FILTER
LOOPBACK
TX AUDIO
BIAS
M1
2.5V
REF
U28D
BUFFER
U41
45 MHZ
HIGH IF AMP
C24
2
L2
5
Z
5
14.85 MHz
TCXO
HF AUDIO
COMP
VCO
Q1
9
FL1
A
FL1
B
CRYSTAL FILTER
R179
FL3
44.55 MHZ
VCO SAMPLE
U3
9
U6A
LED
FLASHER
U5
B
U28
A
U6B
O/L
(J1-25)
OUT-OF-LOCK
DET. DRIVER
U6C
U1
3
+5V
U2
9
E
N
U6D
J11
LEDS
ENABLE
+ 5V
U16
MICROPROCESSOR
TO OPTION 2
(DIAGNOSTICS BD.)
J5, J7
LOW VOLTAGE
RESET
U18
EEPROM
DC POWER
CR31
B
CR33
R
A
D
CR32
T
B
D
CR33
C
B
D
CR32
TX
A
CR31
RS
A
(RTS)
NOISE AMP
Y1
3.6864 MHZ
COMPARATOR
SQUELCH GATE
U26A
RX MUTE
U3
C
RSSI AMP
NOISE RECT
J1
4
AUDIO
INVERT
R41
SQUELCH
INVERTER
U3
D
U3A
AUDIO BUFFER
DISCRIMINATOR
NOISE FILTER
T1
U36
SYNTHESIZER
& PRESCALER
TX /
RX
U32
IF SUBSYSTEM
FL2
REGULATO
R
LOOP FILTER
L17
FREQ.
TRIPLER
L
8
14.85 MHZ REF.
MDS 05-2415A01, Rev. A
5-7/8
U5
D
(IN) TLL
ENABLE
J11
(OUT)
RS-232
ENABLE
E
N
U31
LINE
DRIVER
RECEIVER
(J620)
(J621)
(J623)
R25
U5C
U5
A
MODEM RX LEVEL ADJUST
RX
(J1CLK
17)
EXT.
(J1CLK
24)
CT
(J6S
6)
TD
(J1X
2)
RX
D
(J13)
RT
(J1S
4)
CT
(J1S
5)
DC
D
(J18)
TX
(J1CLK
15)
RT
(J6S
12)
RUS
(J1-10)
RX AUDIO
(J1-11)
VOX AF
(J6-17)
MODEM AF
(J6-1)
RSSI
(J1-21)
CHAPTER 6—TROUBLESHOOTING
If difficulties are experienced with the radio system, the steps outlined below can help isolate
the faulty component. For specific instructions on performing the tests or adjustments recommended in this chapter, refer to Chapter 4—Field Tests and Adjustments. For instructions
on using the Hand-Held Terminal (HHT), refer to Chapter 3—Programming and
Diagnostics.
Troubleshooting assistance is also available from Microwave Data Systems in Rochester, NY
(Telephone No. (716) 242-9600). Please have the complete model number and serial number
of the transceiver ready when calling for assistance. Refer to the inside back cover of this
manual for more information on obtaining factory assistance.
UNIT DOES NOT TRANSMIT OR RECEIVE
1.
2.
3.
Power Supply Evaluation
a. Check for + 13.8 Vdc at transceiver’s primary power connector.
b. Check the in-line fuse in the power cable assembly; if defective, replace with
type 3AG, 3 A fuse.
c. Check for continuity of plug-in fuse F1 (4A/Fast Blo) on the transceiver
motherboard. If it is blown, check for reverse polarity or excessive voltage on
primary power leads. When the problem has been corrected, replace the fuse.
Antenna System Evaluation
a. Check antenna feedline and connections. VSWR should be no higher than 1.5:1.
Higher VSWR values usually will not prevent the radio from functioning, but
may degrade system performance.
Operating Frequencies Review
a. Check the transmit/receive frequencies and other radio operating parameters
using HHT or PC terminal.
UNIT RECEIVES, BUT DOES NOT TRANSMIT
1.
PTT Circuit Evaluation
a. Check keying signal being supplied by RTU. Measure keyline input at DB-25
INTERFACE connector; either Pin 14 or 16 of this connector should be activated.
Alternate—Pin 4 of the INTERFACE connector.
b. Apply + 5 Vdc to Pin 14 (PTT), of the DB-25 INTERFACE connector, or a ground
to Pin 16 PTT of the DB-25 connector. The transceiver should key.
c.
On modem-equipped radios, check the DB-25 INTERFACE connector for proper
RTS (Pin 4) and CTS (Pin 5) signals.
d. Key transmitter with HHT using the KEY command.
Continued on next page.
MDS 05-2415A01, Rev. A
6-1
2.
3.
4.
Transmitter Power Measurement
a. Measure transmitter power output at the ANTENNA connector with an in-line
wattmeter or a service monitor. It should not exceed 5 watts.
Transmit Modulation Evaluation
a. Check to see that transmit audio connections are properly made.
b. Check transmitter deviation and adjust, if necessary.
Transmit Frequency Measurement
a. Check transmit carrier frequency with a service monitor or frequency counter
(± 0.000015% accuracy).
UNIT TRANSMITS, BUT DOES NOT RECEIVE
1.
2.
Receive Audio Evaluation
a. Check for receive audio on Pin 11 of the DB-25 INTERFACE connector.
b. Check for proper receive frequency programming using HHT or PC terminal.
c. Check that RUS line (Pin 10 of DB-25) goes high with a received signal.
Interface Functions—With Diagnostics Board Installed
a. Check power supply voltage (SV).
b. Check 8 volt regulator (VR).
c. Check PLL VCO lock voltage (LV).
d. Check RSSI voltage (RSSI).
e. Check power output (KEY & FPWR).
f. Check programmed transmit and receive frequencies ( FRQ).
UNIT RECEIVES AND TRANSMITS, BUT SYSTEM PERFORMANCE IS POOR
1.
2.
6-2
Transmitter Evaluation
a. Check transmit carrier frequency with a service monitor or frequency counter
(± 0.000015% accuracy).
b. Check transmitter modulation (≈2.5 kHz).
c. Check RF output power level. It should not exceed 5 watts.
Receiver Evaluation
a. Check receive 12 dB SINAD sensitivity at Pin 11 of DB-25 connector
(–117 dBm/0.3 µV).
b. Check audio output level.
c. Check squelch threshold level. Squelch should open at a level greater than
–120 dBm
d. Check Master Station received signal strength using the HHT and the RSSI
command, or measure the DC voltage at Pin 21 of the INTERFACE connector.
(See Figure 2-4 to interpret the DC signal level in dBm.)
TROUBLESHOOTING
MDS 05-2415A01, Rev. A
3.
4.
Antenna System Evaluation
a. Inspect antenna for damage; the feedline for loose, shorted or waterlogged
connections.
b. Check forward and reflected power at ANTENNA connector of transceiver using
in-line wattmeter (VSWR should be less than 1.5:1).
Interface Functions Evaluation
a. Check for secure interface connections at the RTU and at the transceiver.
b. Check the RTS/CTS delay setting—it should be normally be set to a minimum
of 10 ms.
c. Check to see if data is lost at beginning or end of transmission. If lost at
beginning, suspect problem with RTU keyline interface; if at end, squelch tail or
soft carrier dekey timing problems.
d. If soft carrier dekey is needed, check for proper programming of delay with
HHT or PC terminal.
e. If noise from the squelch tail (closing) is interfering with the data flow, then
enable the Squelch Tail Eliminator function in the MDS 4310 using the ESTE
command with the HHT. (Applies to analog systems only.)
f. Check for excessive length of the interface cable. This cable should be only as
long as necessary to reach the radio. If the length exceeds 50 feet, then an
RS-232 to RS-422 Converter Assembly may be required. (MDS P/N 012358A01.)
MDS 05-2415A01, Rev. A
TROUBLESHOOTING
6-3
This page intentionally blank
6-4
TROUBLESHOOTING
MDS 05-2415A01, Rev. A
APPENDIX A—1200 BPS BELL 202T
COMPATIBLE MODEM
Optional System Equipment
Assembly P/N: 03-1815A01
INTRODUCTION
The 03-1815A01 modulator/demodulator (modem) was designed specifically for use with the
MDS 4300 Series Transceivers, allowing it to be mounted within the transceiver housing into
Option 1 jacks—J6 and J8. Figure A-1 shows an assembly drawing of the 1200 bps modem.
This modem is compatible with the Bell 202T standard and is normally used for a 1200 bitper-second (bps) data rate. It will track input data rates as low 50 bps. With this option
mounted within the transceiver enclosure, the MDS 4310 Transceiver can still be programmed through the RS-232 connector, without the need to remove the housing cover.
J6
J8
Figure A-1. 1200 bps Modem PC Board
SPECIFICATIONS
Current Drain:
20 mA from the primary power source
Tone Frequencies:
Mark: 1200 Hz, adjustable
Space: 2200 Hz, adjustable
Data Rates:
50–1200 bps Asynchronous
ALIGNMENT
Chapter 4—Field Tests and Adjustments contains alignment procedures for radios equipped
with 1200 bps modems. The modem alignment consists of setting the Mark tone frequency
(R2), Space tone frequency (R3), and the Receive Data Threshold (R25).
MDS 05-2415A01, Rev. A
A-1
THEORY OF OPERATION (Refer to Figure A-1 and Figure A-2)
Modulator
The modulator consists of a monolithic function generator integrated circuit, U2, which
generates an audio tone whose frequency depends on the state of Pin 9, the data input. A
voltage-controlled oscillator is included in the IC, the frequency of which is determined by
either R2 or R3. When Pin 9 is high, R2 and C3 determine the frequency of oscillation. When
Pin 9 is pulled low, R3 and C3 control the frequency of the oscillator, whose output appears
at Pin 2 of U2.
Normally, for operation in the Bell 202 format, R2 is adjusted to produce a 1200 Hz “mark”
tone and R3 is set for a 2200 Hz “space” tone. Transmit data is supplied to Pin 9 of U2.
Demodulator
U5 is a phase-locked loop (PLL) FSK demodulator. Frequency-shifted audio from the radio
receiver is applied at Pin 2, which is one input of a phase detector. The other input to the
phase detector is the internal voltage-controlled oscillator (VCO), the frequency of which is
determined by C29 and R25. An error voltage is developed by the phase detector when the
incoming audio signal frequency differs from the VCO frequency. This error voltage is
applied to a comparator, whose output is the recovered data information.
A lock detect signal is also derived from the PLL circuit, and this is used to provide a data
carrier detect (DCD) logic signal to the RTU.
Keyline (PTT) Dropout Delay
In order to prevent possible data errors from a noise burst at the termination of the transmit
modulation tone, U3 provides a supervisory control of the data modulator, U2. U3 makes
sure the Data Modulator is turned off at the end of a data transmission only when the
modulating signal has reached the zero or cross-over point.
A-2
APPENDIX A
MDS 05-2415A01, Rev. A
LOW PASS
FILTER
TX AUDIO OUT
DATA MODULATOR
U4A
U2
PTT
DELAY
C3
MODEM PTT
U3
TXD
R2
MARK
ADJ.
MODEM RUS
LOW PASS
FILTER
RX AUDIO IN
R3
SPACE
ADJ.
DATA
DEMODULATOR
DCD
GATE
DCD
U6
U4B
U5
RXD
C29
R25
THRESHOLD
ADJ.
U6B
RTS
10 V
REGULATOR
On-Board Voltage
Regulator & Power
Control
+ 13V IN
+ 10V
U7
5V
REGULATOR
U8
+ 5V
RE
Figure A-2. Bell 202T Compatible Modem Block Diagram
MDS 05-2415A01, Rev. A
APPENDIX A
A-3
This page intentionally blank
A-4
APPENDIX A
MDS 05-2415A01, Rev. A
APPENDIX B
4800 BPS FSK MODEM
Optional System Equipment
Assembly P/N: 03-1831A01
INTRODUCTION
The 03-1831A01 modulator/demodulator (modem) was designed specifically for use with the
MDS 4300 Series Transceivers, allowing it to be mounted within the transceiver housing.
This modem is capable of synchronous or asynchronous operation. With this option mounted
within the transceiver enclosure, the MDS 4310 Transceiver can still be programmed via the
RS-232 connector, without the need to remove the housing cover.
SPECIFICATIONS
Current Drain:
30 mA from the primary power source
Data Rates:
50 to 4800 bps—Asynchronous,
w/internal direct FSK interface
4800 bps—Async/Synchronous,
w/internal direct FSK interface
INSTALLATION
The 03-1831A01 modem installs within the transceiver housing on the transceiver main
board at J6 & J8. The modem contains an eight section set-up and test switch, S1, which is
used to configure the modem for operation in a number of installation arrangements. Table
B-1 describes the function and recommended setting of each of these eight switch sections.
ALIGNMENT
There is no “alignment” of the MDS 4800 bps modem required. However, should the modem
be added to a radio that previously did not have a modem, or a defective modem is replaced
with a new one, it is advisable to check the radio’s deviation and frequency setting before
returning the radio to service. Details on setting the deviation and frequency are covered in
Chapter 4—Field Tests & Adjustments.
THEORY OF OPERATION
Transmit Data
CTS is factory set to go high 10 ms after transmit data is received from the external system
via Pin 2 on the INTERFACE connector. The time period is controlled by the micro-controller,
U16, on the transceiver board, but the period is user programmable (2 to 255 ms). This data
goes through U31 on the transceiver main board for the RS-232 configuration or through
MDS 05-2415A01, Rev. A
B-1
bypass jumpers in place of U31 in the TTL configuration. The transmit data is fed into the
data processor U6.
Level shifting and wave shaping operations cause the data to resemble a smooth audio waveform. This waveform feeds into the modulation input of the transmitter. Deviation and center
frequency are controlled by the transmitter.
Unlike radios with analog modems installed, the transmitter does not transmit a constant
carrier at center frequency when RTS is raised and no data is being sent. It can transmit a
signal above or below the center frequency, depending upon whether the data is a mark or a
space.
With an RS-232 interface, a “Mark” (the normal resting state when no data is being sent),
causes the transmitted frequency to be 1.6 kHz below the nominal center. If the TXD line is
tied high (continuous Space), the frequency will be 1.6 kHz above the nominal center. While
continuous data is being sent, the frequency measures approximately the nominal channel
frequency as the carrier toggles back and forth about the center frequency.
For a TTL interface configuration, a “Mark” is a digital “high” or binary “1” and the “Space”
is a digital “low” or a binary “0”.
SYNC-ASYNC
CONVERTOR
PROM
U5
RS-232
INTERFACE
DATA
SLICER
LOW PASS FILTER
MODEM
RX AUDIO
U4
TC
RC
ETC
U7
U3C
U8
U3B
DATA PROCESSOR
RXD
TXD
U6
DCD
PTT
TAE
U3D
TX
AUDIO OUT
RUS
S1
OPTION SELECT
SWITCHES
10 V
REGULATOR
+ 13V IN
+ 10V
U7
RE
5V
REGULATOR
U8
+ 5V
POWER
REGULATORS &
CONTROL
Figure B-1. MDS 4800 bps Modem Block Diagram
Receive Data
While no carrier is detected, the squelch circuit in the receiver senses the lack of quieting and
forces the DCD low and RXD output to mark condition. It also biases the “slicer” circuit so
that it recognizes the very first mark-to-space transition correctly once a signal is received.
B-2
APPENDIX B
MDS 05-2415A01, Rev. A
When an RF carrier is detected, the receiver squelch forces DCD true and the receiver receives the FSK (Frequency Shift Keyed) signal just as it would any FM modulated signal.
The recovered audio is fed to the modem board which determines the peak excursion of the
received waveform in each direction. The center voltage (halfway) between these excursions
is used as a “slice” voltage for comparison with the incoming waveform. The output of the
comparator is square wave TTL data, identical to that transmitted by the remote station. This
is then fed to U31, the interface IC on the transceiver main board. Received data is then
delivered on the transceiver’s INTERFACE connector–Pin 3.
Synchronizing Data
For asynchronous operation, the modem synchronizes to the incoming transmit data. For
synchronous operation, the modem generates the transmit clock timing signal for use by
external equipment. Data changes on the rising edge of the TX clock signal, and the modem
samples the data on the falling edge of the clock signal.
Table B-1. Settings for the MDS 4800 bps Modem’s Configuration Switch S1
MODEM SWITCHES
4
5
6
7
SYNCHRONIZATION
1
2
3
Synchronous w/internal clock
O
O
O
O
O
O
O
O
Synchronous w/external clock
O
C
O
O
O
O
O
O
Asynchronous—Preferred (factory default setting)
O
C
O
C
O
O
O
O
8
LEGEND: C = CLOSED = ON O = OPEN = OFF
S1
CONFIGURATION
8
1
OPEN
CLOSED
U6
U5
P8
P6
Figure B-2. MDS 4800 bps Modem Assembly Diagram,
P/N 03-1831A01
MDS 05-2415A01, Rev. A
APPENDIX B
B-3
This page intentionally blank
B-4
APPENDIX B
MDS 05-2415A01, Rev. A
APPENDIX C
9600 BPS FSK MODEM
Optional System Equipment
Assembly P/N: 03-1833A01
INTRODUCTION
The 03-1833A01 modulator/demodulator (modem) was designed specifically for use with the
MDS 4300 Series Transceivers, allowing it to be mounted within the transceiver housing.
This modem is capable of synchronous or asynchronous operation at 9600 bits-per-second
(bps). With this option mounted within the transceiver enclosure, the MDS 4310 Transceiver
can still be programmed via the RS-232 connector, without the need to remove the housing
cover.
SPECIFICATIONS
Current Drain:
30 mA from the primary power source
Data Rate:
9600 bps Synchronous or Asynchronous
INSTALLATION
The 03-1833A01 modem installs within the transceiver housing on the transceiver main
board at jacks J6 and J8. The modem contains an eight section set-up and test switch, S1,
which is used to configure the modem for operation in a number of installation arrangements.
Table C-1 describes the function and recommended setting of each of these eight switch
sections.
ALIGNMENT
There is no alignment of the MDS 9600 bps modem required. However, should the modem
be added to a radio that previously did not have a modem, or a defective modem is replaced
with a new one, it is advisable to check the radio’s deviation and frequency setting before
returning the radio to service. Details on setting the deviation and frequency are covered in
Chapter 4—Field Tests & Adjustments.
THEORY OF OPERATION
Transmit Data
CTS is factory set to go high 10 ms after transmit data is received from the external system
via Pin 2 on the INTERFACE connector. The time period is controlled by micro-controller U16
on the transceiver board, but the period is user programmable (2 to 255 ms). This data goes
through U31 on the transceiver main board for the RS-232 configuration or through bypass
jumpers in place of U31 in the TTL configuration. The transmit data is fed into the data
processor U6.
MDS 05-2415A01, Rev. A
C-1
Level shifting and wave shaping operations within U6 cause the data to resemble a smooth
audio waveform. This waveform feeds directly into the modulation input of the digital
transmitter.
With no scrambling, a mark (the normal resting state when no data is being sent), is sent by
an alternating 10101010 pattern at 9600 bits per second. This pattern swings the transmitter
carrier back and forth about the center frequency. If the TXD line goes high (continuous
space), a 0000 or 1111 pattern is transmitted. This causes the radio’s carrier frequency to be
1.6 kHz offset from the center frequency for a 12.5 kHz channel. While continuous data is
being sent, the frequency measures approximately the nominal channel frequency as it
toggles back and forth about the center frequency. In the normal configuration, the scrambler
is enabled, which causes a random bit pattern regardless of whether a mark or space is being
sent. The scrambled signal is detectable by any MDS 9600 bps modem and no operator
configuration is required other than setting it on or off.
Receive Data
While no RF carrier is detected, the squelch circuit in the receiver senses the lack of quieting
and forces the DCD low and RXD output to mark condition. The squelch output also biases
the “slicer” circuit on the interface board so that it recognizes the very first mark-to-space
transition correctly once a signal is received. When an RF carrier is detected, the receiver
squelch forces DCD true (high) and the receiver receives the FSK (Frequency Shift Keyed)
signal just as it would any FM signal. The recovered audio is fed to the modem board.
A sample of the detected receive audio is held by U3A after it passes through a low pass
filter, U3B/C. This sampling takes place after the receiver squelch opens and before the
receive data signaling begins. Two comparators in U8 use this stored voltage as a reference in
recovering the data from the received audio signal. The detected data signal from U8 is fed
into U6 for reconstruction and distribution to external interface equipment through U31, the
interface IC on the transceiver main board.
Synchronizing Data
For asynchronous operation, the modem synchronizes to the incoming transmit data. For
synchronous operation, the modem generates the transmit clock timing signal for use by
external equipment. Data changes on the rising edge of the TX clock signal, and the modem
samples the data on the falling edge of the clock signal.
Table C-1. Settings for the MDS 9600 bps Modem’s Configuration Switch S1
CHARACTER
SIZE*
1
2
Synchronous w/internal clock
N/A
C
O
O
O
O
O
O
O
Synchronous w/external clock
N/A
C
C
O
O
O
O
O
O
Asynchronous #1
8
C
O
O
O
O
C
O
O
Asynchronous #2
9
C
O
O
O
O
C
O
C
Asynchronous #3
10
C
O
O
O
O
C
C
O
Asynchronous #4
11
C
O
O
O
O
C
C
C
SYNCHRONIZATION
3
MODEM SWITCHES
4
5
6
7
8
* Includes start bit, stop bit, data bits & parity.
LEGEND: C = CLOSED (ON)
C-2
APPENDIX C
O = OPEN (OFF)
MDS 05-2415A01, Rev. A
NOTE
The “Alternate” mode is required if asynchronous data has
gaps between characters that are not equal to a multiple of a bit
time, or if 1-1/2 stop bits are used.
SYNC-ASYNC
CONVERTOR
PROM
U5
U4
RS-232
INTERFACE
DATA
SLICER
LOW PASS FILTER
TC
RC
ETC
U7
MODEM
RX AUDIO
U3C
U8
U3B
DATA PROCESSOR
RXD
TXD
U6
U9
SAMPLE SWITCH
DCD
PTT
TAE
U3A
SAMPLE AMP.
TX
AUDIO OUT
RUS
U3D
S1
OPTION SELECT
SWITCHES
+ 10V
10 V
REGULATOR
+ 13V IN
5V
REGULATOR
U7
U8
+ 5V
POWER
REGULATORS &
CONTROL
RE
Figure C-1. MDS 9600 bps Modem Block Diagram
S1
CONFIGURATION
8
1
OPEN
CLOSED
U6
U5
P8
P6
Figure C-2. 9600 bps Modem Assembly Diagram
P/N: 03-1833A01
MDS 05-2415A01, Rev. A
APPENDIX C
C-3
This page intentionally blank
C-4
APPENDIX C
MDS 05-2415A01, Rev. A
APPENDIX D
REMOTE MAINTENANCE MODULE
Optional System Equipment
Assembly P/N: 03-1958A01
INTRODUCTION
The Remote Maintenance feature allows fine-adjustment of several important operating
parameters of an MDS 4310 Transceiver either locally with an HHT (or PC terminal), or
from a distant location over-the-air using MDS 2000 Diagnostics and Control System
Software. This software resides on a personal computer at the system control site.
The master station in the radio system also must be equipped with Remote Maintenance
compatible firmware for over-the-air diagnostics to be possible. Diagnostics over the RF
channel is accomplished using DTMF tones executed by an MDS 4100 Series “SMART”
Master Station. Any MDS 4310 Transceiver on which Remote Maintenance commands are to
be executed must be equipped with a Remote Maintenance Module (P/N 03-1958A01).
The user should be aware that Remote Maintenance commands cannot be implemented
during normal data traffic. That is, normal operation of the entire radio system must stop
before Remote Maintenance commands can be executed. All of the MDS 4310 Transceivers
served by a particular Master Station become unavailable for data exchange when Remote
Maintenance commands are invoked on any transceiver in the radio system. Use of Remote
Maintenance commands, then, should occur at times that are as non-disruptive as possible,
and any affected users should be notified in advance.
The Remote Maintenance Module mounts within the housing of the MDS 4310 Transceiver.
Specifically, the board mates with connectors J5 and J7 on the main transceiver board. See
Figure D-1.
A number of general operating settings are available by connecting an MDS HHT or PC
terminal to the DB-25 INTERFACE connector on the transceiver’s case. Details on the
diagnostic and programming functions of the MDS 4310 are found in Chapter 3—
Programming and Diagnostics.
OPERATION
The Remote Maintenance Module mediates the Remote Maintenance commands between the
HHT or PC terminal and the transceiver. It interprets the control commands and sends the
appropriate instructions to the transceiver. With Remote Maintenance, three important
operating parameters can be adjusted locally, or remotely, within specified bounds. These
parameters are: (1) transmit power level, (2) modulation deviation, and, (3) frequency offset.
The following parameters can be read, but not adjusted using Remote Maintenance: Remote
Unit Temperature, Reflected RF Power, Supply Voltage, and Received Signal Strength.
MDS 05-2415A01, Rev. A
D-1
NOTE
An alternative to the HHT is a personal computer running a
terminal program, such as PCPLUS™, PROCOMM™,
PCTALK™, etc. connected to the radio’s INTERFACE
connector. In this case, the program should be set to 1200 bps,
eight data bits, parity-none and one stop bit. The keyboard
must be set with the caps lock key pressed, as the radio
responds only to commands made in uppercase characters.
Remote Maintenance gives remote access for fine adjustment but does not allow adjustment
of these parameters over the entire range of adjustment of which the radio is capable. For
example, Remote Maintenance allows you to correct the operating frequency of a radio that
has drifted away from its specified rating but it does not allow you to change the operating
frequency to a different channel altogether. Nor is Remote Maintenance a substitute for
periodic or demand-based field maintenance and re-alignment. Instead, it is a means of
keeping the radio at optimal performance without having to visit the radio site in person.
MODULE ADJUSTMENTS & CALIBRATION
The Remote Maintenance Module contains two adjustable controls—Loopback TX Audio
Level (R6), and Temperature Setting (R33). Normally, R6 needs adjustment only when the
module is first installed in the radio. R33 is adjusted at the factory. Refer to Chapter 4—
Field Tests and Adjustments, Test Procedure ➏ for alignment instructions.
NOTE
In a properly aligned system, Remote Maintenance provides
valuable information to service personnel, however, it should
not be considered a replacement for calibrated test equipment.
R6
LOOPBACK TX
AUDIO LEVEL
R33
TEMP. SET
J7
J5
Figure D-1. Remote Maintenance Module, P/N 03-1958A01
DETERMINING THE PRESENCE OF A REMOTE MAINTENANCE MODULE
Radios with a Remote Maintenance Module installed at the factory will have a label on the
case’s exterior identifying the unit’s loopback code. The presence of this label indicates that
the Remote Maintenance Module is probably installed. However, it is possible that a Remote
Maintenance Module was installed after the radio was shipped from the factory, or that the
assembly was removed from the radio. Even though it is impossible to confirm the physical
presence of the module from outside the case, it is possible to test its presence through the
use of the HHT or PC terminal.
D-2
APPENDIX D
MDS 05-2415A01, Rev. A
If you are unsure whether a Remote Maintenance Module is installed in the transceiver, open
the Diagnostics Channel and enter the STAT command. The display responds with the type of
diagnostics that are installed in the transceiver. The forth character will be I for “installed”, or
U for “uninstalled.” The other characters describe additional details about the radio’s
configuration. Refer to Table 3-2 for a complete listing of the STAT characters.
NOTE
If a Remote Maintenance Module is installed while the power
is on, the transceiver will show that the board is NOT installed
until the DC power to the radio is shut off for at least five (5)
seconds, and then turned back on.
INSTALLATION & REPLACEMENT
Normally, the installation of the Remote Maintenance Module is done at the factory; the only
field activities are the programming of the loopback code, setting the diagnostics deviation,
and the removal and replacement of a defective assembly. This section describes the installation and removal of the Remote Maintenance Module. Refer to Chapter 4—Field Tests and
Alignments, Test ➏ for instructions on setting the loopback code and for adjusting the diagnostics deviation.
Physical Installation/Removal
The following procedures summarize the removal and replacement of a Remote Maintenance
Module.
To remove the module:
1. Disconnect primary power to the unit and remove the transceiver’s top cover.
2. With a slight rocking motion, remove the module from the Option 2 position (Jacks
J5 and J7) on the main transceiver board.
To install the module:
1. Disconnect primary power to the unit and remove the transceiver’s top cover.
2. Plug the module into the Option 2 position (Jacks J5 and J7) on the transceiver
motherboard.
3. Make sure connectors are fully mated, and there are no bent pins that might prevent
proper connector seating or module operation.
4. Re-apply primary power and test the system for normal operation.
5. With the HHT or PC terminal, use the STAT command to verify the presence of the
module (see Determining the Presence of a Remote Maintenance Module, in the
preceding subsection), then program in the unit’s loopback code, set the diagnostic
level (Mode 1, 2 or 3) and check the transmit modulation level. In addition, if the
installation is a field upgrade, then Test Procedure ➏ in Chapter 4 must be followed.
MDS 05-2415A01, Rev. A
APPENDIX D
D-3
NOTE
Once a loopback code has been entered, typing the L B C
command results in a display of the code, followed by the letter
I to indicated that it is “Installed.” If a loopback code has not
been programmed, the letters UI for “Uninstalled” will be
displayed, even if the module is present, since a valid code has
not been entered. Once the loopback code is entered and the
radio is shut down and re-powered up, the indicator will be I
for “Installed.”
TESTING THE LOOPBACK CODE
This section presents three basic test options to verify that the transceiver is responding
properly to its programmed loopback code. Chapter 4—Field Tests and Adjustments, Test
Procedure ➏ covers procedures for programming a new loopback code.
The Remote Maintenance Module receives instructions over-the-air in the form of DTMF
signals from the system’s master station. Outgoing data from the Remote Maintenance
Module is also modulated with DTMF signals.
Local Testing with a DTMF Encoder
A programmable DTMF encoder with an audio level output of –10 dBm can be attached to
Pin 22 of the INTERFACE connector J1 to emulate incoming DTMF polling signals from the
system’s master station. The radio’s four digit loopback code can then be sent through J1-Pin
22 to the Remote Maintenance Module.
A properly decoded Loopback Code will key the radio and generate a series of DTMF signals
and a short, but steady, tone that is used by the master station for frequency and deviation
measurements. This basic response can be monitored on a communications service monitor.
Make sure to connect the ANTENNA jack of the transceiver to the transmit input of the service
monitor before starting the test.
Local Testing with a Communications Service Monitor
Many communications service monitors are capable of providing sequential DTMF encoding
on their RF test signals. Connect the transceiver to the monitor’s internal dummy load and
program the encoder to generate the four digit loopback code sequence as an on-channel
DTMF signal. Monitor the response from the transceiver as previously discussed.
Remote Testing with a “SMART” Master Station
With the radio installed in the system and the master station connected to a personal
computer running the MDS 2000 Diagnostic & Control System software, poll the remote
station using its loopback code. The appropriate diagnostic information should be displayed
on the PC screen. Review the software operating instructions for details.
TROUBLESHOOTING
If the Remote Maintenance Module does not respond to a four digit DTMF loopback code,
verify the installation and basic operation of the assembly by following this procedure.
1. Connect the HHT or ASCII terminal to the transceiver as previously described.
D-4
APPENDIX D
MDS 05-2415A01, Rev. A
Radio RF TX Power Control
U10 is a 100-position 100k EEPOT that controls the radio’s RF TX power. U10 is configured
as a ratiometric resistor that sources a voltage to control the transmitter power. The voltage
being sourced by the EEPOT is controlled by the micro-controller on the transceiver’s main
circuit board. The setting is controlled by the firmware through the diagnostics channel, both
locally and remotely.
Radio Center Frequency Control
U9 is a 100-position 100k EEPOT that controls the radio carrier frequency. U9 is configured
as a ratiometric resistor that sources a voltage to control the carrier frequency. The voltage
being sourced by the EEPOT is controlled by the micro-controller on the transceiver’s main
PC board. The setting is controlled by the firmware through the diagnostics channel, both
locally and remotely.
D-6
APPENDIX D
MDS 05-2415A01, Rev. A
APPENDIX E
ORDER WIRE MODULE
Optional System Equipment
Kit P/N: 02-1297A01
INTRODUCTION
The Order Wire Module (Figure E-1) is an optional adapter for the MDS 4310 Transceiver
which makes two-way voice communications possible for the initial set-up and testing of the
radio link. If the Order Wire Module is connected between the transceiver and the RTU, and
a telephone handset is plugged into the Order Wire Module, it is possible to listen to the data
communications on the channel. Receiver audio from the transceiver can be monitored by
using the earpiece on the handset. Speaking into the handset microphone activates the VOX
circuit in the adapter, allowing voice communications with the master or base station.
As a convenience, the Order Wire Module has been designed to work with a standard fourwire modular (RJ-11-4) telephone handset, available from any telephone supply store or
electronic parts distributor.
FEMALE CONNECTOR
TO RTU OR MODEM
P/N 03-1294A01
TRANSMIT INDICATOR
(LED)
ORDER WIRE MODULE
Male connector
Radio
Female connector
RTU
HANDSET
PHONE JACK
MALE CONNECTOR
TO RADIO
P/N 03-1295A02
Figure E-1. Order Wire Module
MDS 05-2415A01, Rev. A
E-1
THEORY OF OPERATION (Refer to Figure E-2 and Figure E-3)
Microphone audio is first pre-emphasized by C-1 and R5. R4 provides current for the carbon
microphone typically used in telephone handsets. U1A amplifies and limits the microphone
audio, with R17 setting the VOX microphone gain. R19 sets the deviation and is normally set
for –10 dBm output to the transmitter. Solid state switch U2 automatically switches between
the handset audio and the external RTU or modem audio in response to the VOX circuit built
into the adapter. When the limiter is driven into limiting, audio is present at U1 Pin 2. CR1
detects this audio, with C5 and R12 providing a VOX delay.
C4
R17
R13
R6
R16
U1
J1
J2
C2
C3
R3
R5
C1
As long as the microphone audio is below clipping level, U1 Pin 2 remains a virtual ground
and PTT remains low. U1D amplifies the received audio, with R18 setting the volume. R13
couples some of the TX audio into this amplifier to provide “sidetone” for the handset (so
you can hear yourself talk in the earpiece, just as with a regular telephone). R16 and C4
provide de-emphasis for the received audio.
C11
+
C5
C8
R4
R11
R1
R2
R15
R14
CR1
R12
+
J3
U2
R18
+
C6
CR2
CR3
R10
R8
R7
R9
+
CR4 C10
+
+
C7
R19
C9
+
Figure E-2. Order Wire Board Component Layout
E-2
APPENDIX E
MDS 05-2415A01, Rev. A
This page intentionally blank
E-4
APPENDIX E
MDS 05-2415A01, Rev. A
APPENDIX H
MDS 4310-HL DATA TRANSCEIVER
FOR USE IN HAZARDOUS LOCATIONS
INTRODUCTION
The MDS 4310-HL Data Transceiver is available for use in Class I, Division 2, Groups A, B,
C, and D Hazardous Locations. Such locations are defined in Article 500 of the National Fire
Protection Association (NFPA) publication NFPA 70, otherwise known as the National
Electrical Code.
The MDS 4310-HL Data Transceiver has been recognized for use in these hazardous
locations by two independent agencies —Underwriters Laboratories (UL) and Factory
Mutual Research Corporation (FMRC). The UL certification for the transceiver is as a
Recognized Component for use in these hazardous locations, in accordance with UL
Standard 1604. The FMRC Approval is in accordance with FMRC Standard 3611.
CONDITIONS OF APPROVAL
The MDS 4310-HL Data Transceiver is not acceptable as a stand-alone unit for use in the
hazardous locations described above. It must either be mounted within another piece of
equipment which is certified for hazardous locations, or installed within guidelines, or
conditions of approval, as set forth by the approving agencies. These conditions of approval
are as follows:
1. The transceiver must be mounted within a separate enclosure which is suitable for
the intended application.
2. The antenna feedline, DC power cable and interface cable must be routed through
conduit in accordance with the National Electrical Code.
3. Installation, operation and maintenance of the transceiver should be in accordance
with the transceiver's installation manual, and the National Electrical Code.
4. Tampering or replacement with non-factory components may adversely affect the
safe use of the transceiver in the hazardous locations, and may void the approval.
Refer to Articles 500 through 502 of the National Electrical Code (NFPA 70) for further
information on hazardous locations and approved Division 2 wiring methods.
MDS 05-2415A01, Rev. A
H-1
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H-2
APPENDIX H
MDS 05-2415A01, Rev. A
APPENDIX I
CANADIAN CERTIFICATION
RSS APPROVALS
The MDS 4310 Transceiver has been approved for use in Canada under Radio Standards
Specification (RSS) 119 and 122 of Industry Canada (IC) certification. The frequency ranges
and channel spacings for this application are as follows:
RSS-119
Frequency Range:
Channel Spacing:
Power Output:
RSS-122
Frequency Range:
Channel Spacing:
Power Output:
Transmit —406.1–430, 450–470 MHz
Receive —406.1–430, 450–470 MHz
25 kHz
1 to 5 watts, continuously variable
Transmit —406.1–430 MHz
Receive —406.1–430 MHz
12.5 kHz
1 to 5 watts continuously variable
RESTRICTIONS
The Industry Canada approval is valid subject to the restrictions listed below:
1. The MDS 4310 may only be used with a built-in modem at speeds of either 1200,
4800 or 9600 bps. No external modems or other signaling devices using external
transmit audio input (Pin 9 of the INTERFACE connector) are permitted.
2. The Order Wire Module (MDS P/N 02-1297A01) may not be used with the
transceiver.
MDS 05-2415A01, Rev. A
I-1
This page intentionally blank
I-2
APPENDIX I
MDS 05-2415A01, Rev. A
APPENDIX J
AUDIO PROCESSING MODULE
Optional System Equipment
Assembly P/N: 03-2301A01
INTRODUCTION
The Audio Processing Module is used in applications where no method of keying the remote
transceiver is provided by the RTU or modem. The assembly senses the presence of an audio
tone on the transmit audio line and, in turn, keys the transmitter. This function is typically
called a VOX function. When installed in the MDS 4310 Transceiver, the Audio Processing
Module is mounted in the Option 1 position on the main transceiver board. See Figure J-3.
Figure J-1 and J-2 show the component layouts for the Audio Processing Modules. The
boards contain an array of switches to configure the assembly for a variety of interface
requirements. The assemblies consist several circuits—a VOX circuit (discussed above), a
transmit audio pre-emphasis circuit, receive audio de-emphasis circuit and limiter circuitry.
These circuits may be turned on and off independently using the configuration switches.
The automatic level control (ALC) circuitry is continuously enabled and provides the correct
audio level for the transceiver. The audio input level should be between -30 and 0 dBm.
OPTION 1—
Modem PC Assembly or
Audio Processing Module
OPTION 2—
Remote Maintenance Module
or Diagnostic & Loopback Module
TRANSCEIVER
PC BOARD
Figure J-1. Audio Processing Module Installation Diagram
SPECIFICATIONS
Power Requirements:
Key-up Time:
Release Time:
MDS 05-2415A01, Rev. A
+10 Vdc @ 1 mA standby; 8 mA activated
Less than 2 milliseconds; 0.25 ms typical
Less than 10 milliseconds; 5 ms typical
J-1
ALIGNMENT
There are no adjustments required on the Audio Processing Module. However, when the
module is installed in a radio that was previously aligned for use with a modem, two adjustments need to be made on the transceiver motherboard —Receive Audio and Transmit
Deviation. Refer to Chapter 4—Field Tests and Adjustments, Test Procedure ➋, for adjustment procedures.
CONFIGURATION
Tables J-1 and J-2 list various functions of the DIP switch on the PC board. The
configuration chosen for some functions, such as the filtered/flat response depends on the
specific requirements of your system. If technical assistance is required, contact MDS,
Systems Engineering Department.
NOTE
When the VOX Function is used in an MDS 4310 Transceiver,
the Squelch Tail Eliminator (STE) circuitry on the transceiver’s
motherboard should be turned off. The status of this operating
parameter can be checked, and if necessary set to OFF, using
the Hand-Held Terminal (HHT). For more information on
using the HHT, see Chapter 3—Programming and Diagnostics,
especially the section “Programming Examples” and Table 3-2.
Table J-1 lists the configuration switch settings for the MDS P/N 03–2301A01. Figure J-2
shows the component layout for the PC board.
R22
R38
C6
R18
U7
R41
P8
R6
U6
C24
C20
VOX 4000 PCB
R14
1
2
3
4
5
6
7
8
R10
R17
C28
R15
CR4
CR1
C30
C17
C29
R19
R5
R33
CR3
C15
R12
C26
U3
MICROWAVE DATA SYSTEMS
C22
C23
C27
R11
R4
C7
R26
R25
U2
R13
R16
R24
CR2
C12
C31
U8
C1
R1
C9
R3
R45
C11
C2
R36
ON TXFILT
RXAUD
LIMIT
DEEMPH
PREEMP
VOX
RXFILT
ENABLE
R48
R23
C21
R21
R20
R30
C3
R2
R9
R7
R44
C4
C14
C5
R8
R27
U4
C10
C19
R31
U1
C8
C13
R46
R43
C18
R28
R29
R47
C25
P6
Figure J-2. 03-2301A01 Audio Processing Module
Table J-1. P/N 03–2301A01 Configuration Switch Settings
SWITCH POSITION
J-2
FUNCTION
SW1
OFF
ON
Filtered/Flat TX Audio
1
No VOX Keyline
VOX Keyline
RX Audio Enable
2
Filtered
Flat
Limiter ON/OFF
3
No TX Limiter
TX Limiter
De-Emphasis ON/OFF
4
No De-Emphasis
De-Emphasis
Pre-emphasis ON/OFF
5
No Pre-Emphasis
Pre-Emphasis
VOX Enable
6
VOX Disabled
VOX Enabled
Filtered/Flat RX Audio
7
Filtered
Flat
TX Audio Enable
8
No Processing
Processing
APPENDIX J
MDS 05-2415A01, Rev. A
In Case of Difficulty...
The MDS 4310 Transceiver is designed for long life and trouble-free operation. However,
this equipment, as with all electronic equipment may have an occasional component failure.
The following information will assist you in the event that servicing becomes necessary.
Factory Technical Assistance
Technical assistance for MDS products is available from our Systems Engineering Group
during business hours (8:30 A.M.–5:00 P.M. EST). When calling, please give the complete
model number of the radio, along with a description of the trouble symptom(s) that you are
experiencing. In many cases, problems can be resolved over the telephone, without the need
for returning the unit to the factory.
Please use the following telephone numbers for product assistance:
716-242-9600 (Phone)
716-242-9620 (FAX)
Factory Repairs
Component level repair of the transceiver is not recommended in the field. Many transceiver
components are installed using surface mount technology, which requires specialized training
and equipment for proper servicing. For this reason, the equipment should be returned to the
factory for any PC board repairs. The factory is best equipped to diagnose, repair and align
your radio to its proper operating specifications.
If return of the equipment is necessary, you will be issued a Returned Material Authorization
(RMA) number. The RMA number will help expedite the repair so that the equipment can be
repaired and returned to you as quickly as possible. Please be sure to include the RMA
number on the outside of the shipping box, and on any correspondence relating to the repair.
No equipment will be accepted for repair without an RMA number.
A statement should accompany the radio describing, in detail, the trouble symptom(s), and a
description of any associated equipment normally connected to the radio. It is also important
to include the name and telephone number of a person in your organization who can be
contacted if additional information is required.
The radio must be properly packed for return to the factory. The original shipping container
and packaging materials should be used whenever possible. All factory returns should be
addressed to:
Microwave Data Systems
Customer Service Department
(RMA No. XXXX)
175 Science Parkway
Rochester, NY 14620 USA
When repairs have been completed, the equipment will be returned to you by the same
shipping method used to send it to the factory. Please specify if you wish to make different
shipping arrangements.
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