Novatel | WAAS GUS SIGGEN | User guide | Novatel WAAS GUS SIGGEN User Guide

Novatel WAAS GUS SIGGEN User Guide
WAAS GUS
Signal Generator
USER GUIDE
OM-20000187 v1
November 2019
Proprietary Notice
WAAS GUS Signal Generator User Guide
Publication Number:
Revision Level:
Revision Date:
OM-2000187
1
November 2019
Limited Rights Notice
These data are submitted with limited rights under Contract No. 693KA8-18-C-00013. These data may be
reproduced and used by the Customer with the express limitation that they will not, without written permission of
the Contractor, be used for purposes of manufacture nor disclosed outside; except that the Customer may disclose
these data outside for the following purposes, if any; provided that the Customer makes such disclosure subject to
prohibition against further use and disclosure:
The information provided herein may be disclosed by the Customer for any purpose related to the use and operation
of related NovAtel supplied equipment, including without limitation, maintenance, revision of equipment, design
upgrades, testing, and any other required Customer activity.
This Notice must be marked on any reproduction of these data, in whole or in part.
The information contained in this document is subject to change without notice and should not be construed as a
commitment by NovAtel Inc. unless such commitment is expressly given in a covering document.
NovAtel® is a registered trademark of NovAtel Inc.
All other brand names are trademarks of their respective holders.
© Copyright NovAtel Inc. All rights reserved.
Unpublished rights reserved under International copyright laws.
2
WAAS GUS Signal Generator User Guide Rev 1
Table of Contents
Customer Service
8
Notices
9
Foreword
10
1 Introduction
11
1.1 Features...................................................................................................................................... 13
1.2 Accessories and Options ............................................................................................................ 13
1.3 Functional Overview ................................................................................................................... 13
2 Minimum Connections
15
3 Setup Considerations
19
3.1 Front Panel Functionality ............................................................................................................ 19
3.1.1 H/W Fault........................................................................................................................... 19
3.1.2 10 MHz .............................................................................................................................. 19
3.1.3 CW Mode........................................................................................................................... 19
3.1.4 Transmit Inhibit (Tx INHIBIT)............................................................................................. 19
3.1.5 Initiated Built in Test (IBIT) ................................................................................................ 20
3.1.6 1PPS ................................................................................................................................. 20
3.2 Rear Panel Functionality ............................................................................................................. 20
3.2.1 Power ................................................................................................................................ 20
3.2.2 CW Switch ......................................................................................................................... 21
3.2.3 Ground Screw.................................................................................................................... 21
3.2.4 CMP and WMP.................................................................................................................. 21
3.2.5 Code PPS Output .............................................................................................................. 21
3.2.6 1PPS In ............................................................................................................................. 21
3.2.7 10 MHz In and 10 MHz Out ............................................................................................... 21
3.2.8 RF Out ............................................................................................................................... 22
3.2.9 IF Out................................................................................................................................. 22
4 Operation
24
4.1 Communications with the Signal Generator................................................................................ 24
4.1.1 Serial Port Default Settings ............................................................................................... 24
4.1.2 Communicating Using a Remote Terminal........................................................................ 24
4.1.3 Communicating Using a Personal Computer .................................................................... 24
4.2 Message Control and Data Lines................................................................................................ 24
4.2.1 Other Control Lines ........................................................................................................... 25
5 Messages
26
5.1 WMP Message Structure ............................................................................................................ 26
5.1.1 Packet Synchronization Field ............................................................................................ 26
5.1.2 L1/L5 Indication Field ........................................................................................................ 26
5.1.3 Command Message .......................................................................................................... 27
5.1.4 Status Message................................................................................................................. 37
5.1.5 CRC-16/CCITT Checksum Field ....................................................................................... 44
5.2 Error Handling ............................................................................................................................. 44
6 Firmware Updates
46
6.1 Contacting the NovAtel Customer Support ................................................................................. 46
6.2 Downloading the Files................................................................................................................. 47
WAAS GUS Signal Generator User Guide Rev 1
3
Table of Contents
6.3 Decompressing the Files ............................................................................................................. 47
6.4 Running WinLoad ........................................................................................................................ 47
6.4.1 Open a File to Download ................................................................................................... 48
6.4.2 Downloading firmware ....................................................................................................... 50
A Technical Specifications
4
51
WAAS GUS Signal Generator User Guide Rev 1
Figures
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
WAAS GUS Signal Generator System Overview ......................................................................... 12
Signal Generator .......................................................................................................................... 13
Interface Block Diagram ............................................................................................................... 14
Signal Generator Setup Example ................................................................................................. 16
Coaxial Cable ............................................................................................................................... 17
Power Switch ............................................................................................................................... 17
Signal Generator Front Panel ...................................................................................................... 19
Close-up of Connectors on Rear Panel ....................................................................................... 20
RS-485 Symbol Timing Diagram .................................................................................................. 25
Application of Frequency/Chipping Rate Ramp ........................................................................... 35
Input Command Flowchart ........................................................................................................... 36
Serial Number and Version Label ................................................................................................ 46
Main Screen of WinLoad .............................................................................................................. 48
WinLoad’s Open Dialog ............................................................................................................... 48
Open File in WinLoad ................................................................................................................... 49
COM Port Setup ........................................................................................................................... 49
Update Process Complete ........................................................................................................... 50
Signal Generator Dimensions ...................................................................................................... 51
Power Cable ................................................................................................................................. 55
WAAS GUS Signal Generator User Guide Rev 1
5
Tables
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
6
External Reference Characteristics ............................................................................................... 21
L1 IF Bandwidth Requirements ..................................................................................................... 22
IF Output Phase Noise .................................................................................................................. 23
L5 IF Bandwidth Requirements ..................................................................................................... 23
Packet Format ............................................................................................................................... 26
Packet Synchronization Field ........................................................................................................ 26
Packet Synchronization Field Bit Format.......................................................................................26
L1/L5 Indication Field .................................................................................................................... 27
L1/L5 Indication Bit Field ............................................................................................................... 27
Command Message Fields............................................................................................................ 27
Command Message Identifier Field ............................................................................................... 28
Command Message Identifier Bit Fields ........................................................................................28
L1/L5 Control Command Bit Fields................................................................................................ 28
L1/L5 Control Command Field....................................................................................................... 29
Resulting I Modulation Format....................................................................................................... 29
Resulting Q Modulation Format..................................................................................................... 30
L1 Initialization Command Fields .................................................................................................. 30
L5 Initialization Command Fields 500 SPS ................................................................................... 31
Symbol Rate/RF Configuration Field ............................................................................................. 31
Sub-Chip Field............................................................................................................................... 32
Code Chip Advance Field .............................................................................................................. 32
Symbol Advance Field ................................................................................................................... 32
L1 I Channel G2 Coder Initialization Field .................................................................................... 32
L1 Q Channel G2 Coder Initialization Field ................................................................................... 33
L5 I Channel XB(I) Coder Initialization Field.................................................................................. 33
L5 Q Channel XB(Q) Coder Initialization Field .............................................................................. 33
L1/L5 Code Chip Rate and Carrier Frequency Command Fields .................................................. 34
Code Chip Rate Field .................................................................................................................... 34
Code Chip Rate Ramp Field.......................................................................................................... 34
Carrier Frequency Field Bit Format ............................................................................................... 34
Carrier Frequency Ramp Field Bit Format..................................................................................... 35
Status Message Fields .................................................................................................................. 37
Uplink Range Fields ...................................................................................................................... 37
Uplink Range Code Chip Sub-Phase Field ................................................................................... 38
Uplink Range Code Chip Counter Field ........................................................................................ 38
Uplink Range Symbol Counter Field ............................................................................................. 38
Switch Status Field ........................................................................................................................ 38
Switch Status Bit Fields ................................................................................................................. 38
Error Status Field........................................................................................................................... 39
Error Status Bit Fields.................................................................................................................... 39
Hardware Status Field ................................................................................................................... 41
Hardware Status Bit Fields ............................................................................................................ 41
Reset Command Second Epoch Counter ..................................................................................... 42
Hardware Reset Second Epoch Counter ...................................................................................... 42
Firmware Version Number Field .................................................................................................... 43
FPGA Version Number Field ......................................................................................................... 43
Signal Generator State Field ......................................................................................................... 43
Signal Generator State Value........................................................................................................ 43
WAAS GUS Signal Generator User Guide Rev 1
Tables
49
50
51
52
53
54
55
CRC-16/CCITT Checksum Field................................................................................................... 44
CRC-16/CCITT Checksum Field................................................................................................... 44
CRC-16-CCITT Characteristics..................................................................................................... 44
Errors ............................................................................................................................................ 45
Target Card Identification.............................................................................................................. 49
L1 and L5 WMP Connector Pin-Out Descriptions ........................................................................ 54
L1 and L5 CMP Connector Pin-Out Descriptions ......................................................................... 54
WAAS GUS Signal Generator User Guide Rev 1
7
Customer Service
Contact Information
If you have any questions or concerns regarding your WAAS GUS Signal Generator, please log a support request
with NovAtel Customer Support using one of the following methods:
Log a Case and Search Knowledge:
Website: www.novatel.com/support
Log a Case, Search Knowledge and View Your Case History: (login access required)
Web Portal: https://novatelsupport.force.com/community/login
E-mail:
support@novatel.com
Telephone:
U.S. and Canada: 1-800-NOVATEL (1-800-668-2835)
International: +1-403-295-4900:
WAAS GUS Signal Generator Firmware Updates
Firmware updates are firmware revisions to an existing model, which improves basic functionality of the signal
generator.
The process for obtaining firmware updates is discussed in Chapter 6, Firmware Updates starting on page 46. If
you need further information, please contact NovAtel using one of the methods given above.
8
WAAS GUS Signal Generator User Guide Rev 1
Notices
This equipment has been tested and found to comply with the limits for a class A digital device, pursuant to Part 15
of the FCC rules. These limits are designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance
with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment
in a residential area is likely to cause harmful interference in which case the user will be required to correct the
interference at his own expense.
Changes or modifications to this equipment not expressly approved by NovAtel Inc. could result in violation of
FCC and CE Marking rules and void the user’s authority to operate this equipment.

To maintain compliance with the limits of a Class A digital device, you must use properly
shielded interface cables when using the serial ports. Appropriate cables include Belden #9539,
or equivalent, and Belden #8770 cable for input power source (ensuring the shield is connected
to the protection ground).

CAUTION:

CAUTION:

Except for the externally accessible AC Fuses located on the rear panel, the WAAS GUS Signal
Generator is not user-serviceable. In the event of any failure of the unit, do NOT remove any
cards or covering panels from the unit. Return the unit to the factory for repair.
Double pole/neutral fusing
The WAAS GUS Signal Generator must be installed in a Restricted Access Location only.
Where applicable, follow the electrical codes for the country of installation. Examples of country codes include:
•
USA
National Electrical Code (NFPA 70)
•
Canada
Canadian Electrical Code (CSA C22)
•
UK
British Standards Institute (BSI 7671)
WAAS GUS Signal Generator User Guide Rev 1
9
Foreword
Congratulations!
Congratulations on your purchase of the Wide Area Augmentation System (WAAS) Signal Generator designed to
generate a Ground Uplink Station (GUS) signal.
NovAtel is an industry leader in state-of-the-art GPS receiver and Signal Generator design. We believe that our
WAAS GUS Signal Generator will meet your high expectations, and are working hard to ensure that future products
and enhancements will maintain that level of satisfaction.
This is your primary hardware and software reference.
Scope
This manual contains sufficient information on the installation and operation of the WAAS GUS Signal Generator
and its software to allow you to effectively integrate and fully operate it. It is beyond the scope of this manual to
provide details on service or repair. Contact your local NovAtel dealer for any customer-service related inquiries.
The WAAS GUS Signal Generator utilizes a comprehensive user-interface command structure, which requires
communications through its WAAS Message Processor (WMP) communications (COM) ports. WAAS GUS Signal
Generator commands and logs can be found in Chapter 5, Messages starting on Page 26.
What’s New in Rev 1 of this manual?
• Describes the WAAS GUS Signal Generator
• Quadrature channel enhancements
• Default and user selectable alternate RF output frequencies at a higher output signal level
• TNC or Type-N connectors used for RF external interfaces
Equipment Compatibility
The WAAS GUS Signal Generator (NovAtel P/N 01020347) is compatible with the legacy WAAS GUS-TYPE 1
Signal Generator (P/N 01017287) with the following exceptions and clarifications:
• The use of TNC connectors throughout (instead of BNC).
• The RF Output level has been increased to -50 dBm (from -100 dBm). The Main IF Output level of -20 dBm
remains unchanged.
• Additional commands have been added to support additional functionality. The equipment will operate as
the legacy unit when controlled with the legacy command set.
10
WAAS GUS Signal Generator User Guide Rev 1
Chapter 1
Introduction
The WAAS GUS Signal Generator is a high performance L1/L5 Signal Generator. It generates a modulated
Intermediate Frequency (IF) signal that is upconverted, amplified and transmitted to a Geo-stationary Earth Orbit
(GEO) satellite. The primary GUS interfaces to the Signal Generator are the Safety Computer (SC), Radio
Frequency Uplink (RFU) and Frequency Distribution Amplifier (FDA). The Signal Generator also provides, for L1:
• Coarse/Acquisition (C/A) codes with Pseudo Random Number (PRN) values of 120 to 158 inclusive
(selectable via the initialization command)
• 70 MHz Binary-Phase Shift Keyed (BPSK) modulated or Quadrature-Phase Shift Keyed (QPSK) modulated
IF output signal generation using the SBAS message with the selected 1023 bit PRN code
• In-phase (I) channel, I channel with dataless quadrature (Q) channel or I channel with independent data on
the Q channel
• User configurable 1227.6 MHz (default) or 1575.42 MHz (alternate) RF output signal carrying the
configured modulation for L1
• L5 codes with PRN values of 120 to 158 inclusive (selectable using the Initialization Command, see Page
30)
• 70 MHz BPSK or QPSK modulated IF output signal generation using the SBAS message with the selected
10230 bit PRN code
• In-phase Manchester encoded (I) channel, I channel with dataless quadrature (Q) channel or I channel with
independent Manchester enclosed data on the Q channel
• User configurable 1176.45 MHz (default) or 1227.6 MHz (alternate) RF output signal carrying the
configured modulation for L5
The Signal Generator consists of the Baseband Signal Generator (BSG), IF Signal Generator (ISG) and the
Loopback Signal Generator (LSG). Figure 1 shows an example of a system containing the Signal Generator and
Receivers.
WAAS GUS Signal Generator User Guide Rev 1
11
Chapter 1
Introduction
Figure 1: WAAS GUS Signal Generator System Overview
Reference
Description
Reference
Description
1
RFU antenna
11
L1/L5 IF signals
2
GEO satellite
12
L1 GPS, L2 GPS, L1 GEO, L5 GEO
3
RF Upconverter and Power Amplifier
13
L1/L5 RF loop back from satellite
4
WAAS GUS Signal Generator
14
RF Switch
5
Receiver (WAAS G-III)
15
L-Band Filter and Low Noise Amplifier
6
RS-485 message input from CMP
16
L1 and L5 at L2 SIGGEN RF loop
7
RS-232 command input from WMP
17
L1 and L5 TLT
8
GPS antenna
18
L1 and L5 GEO or TLT
9
Test loop translator
19
Power combiner/splitter
10
C1/C5 uplink
Figure 1 shows a high level implementation of a WAAS GUS setup (see Chapter 2, Minimum Connections on
Page 15 and Chapter 3, Setup Considerations on Page 19, for more information on this topic). Figure 2 shows the
Signal Generator Front.
12
WAAS GUS Signal Generator User Guide Rev 1
Introduction
Chapter 1
Figure 2: Signal Generator
1.1
Features
The Signal Generator has the following standard features:
• 19” rack-mountable 3U stainless steel enclosure
• NovAtel's advanced Signal Generator technology
1.2
Accessories and Options
The Signal Generator can be used with the following accessories:
• Power cable to connect the Signal Generator to a 100 to 240 V AC power source
• Optional Data Source Modules (used in a test environment and for firmware loading)
• Optional coaxial cables for the TNC and Type-N connectors on the Signal Generator
• Optional (WAAS G-III) Receiver
Should you need to order an accessory or a replacement part, contact NovAtel.
1.3
Functional Overview
The Signal Generator is comprised of two independent L1 and L5 generators which precisely control the frequency
and phase of L1/L5 code and carrier signals and generate two independent L1 and L5 70 MHz IF signals. The L1 IF
output has the L1 message structure with a factory configurable IF bandwidth of 2, 4 or 22 MHz for the Signal
Generator. The L5 IF output has the L5 signal structure with an IF bandwidth of 22 MHz.
The Signal Generator provides two loopback signals that are monitored by the WAAS G-III Receiver. These RF
signals are frequency upconverted replicas of the 70 MHz L1 and L5 outputs. By default, the 70 MHz L1 is
upconverted to 1227.6 MHz. Similarly, by default, the 70 MHz L5 is upconverted to 1176.45 MHz. The user can
select alternate RF frequencies of 1575.42 MHz for the L1 signal and 1227.6 MHz for the L5 signal.
The L1 and L5 Signal Generators share a common 10 MHz frequency source from the GUS frequency standard and
a 1PPS timing reference from the GUS receiver. The command and status interface between the Signal Generator
and the WAAS GUS Message Processor (WMP) is independent for L1 and L5. Similarly, the message interface
with the Comparator Message Processor (CMP) is independent for L1 and L5. This allows for independent L1 and
L5 control and message data streams.
The primary signals generated are output on 70 MHz IF carriers which, outside the unit, are subsequently frequency
upconverted to the necessary uplink frequencies. The Signal Generator contains facilities to precisely control the
frequency and phase of both the code modulation and carrier of the generated signals.
WAAS GUS Signal Generator User Guide Rev 1
13
Chapter 1
Introduction
A quadrature channel can be added to the L1 and L5 signals within the Signal Generator. When used, the normal
signal is referred to as the I channel, and the quadrature signal is referred to as the Q channel. See also Section
5.1.3.2, Control Command starting on Page 28.
Figure 3 shows the interfaces of the Signal Generator.
Figure 3: Interface Block Diagram
After a cold start or after a power reset, the Signal Generator performs an Initiated Built-in Test (IBIT) memory
self-test and internal calibration.
Provided a 1PPS reference source is made available to the Signal Generator, it can receive WAAS messages from
the Safety Computer within 2 minutes of powering up.
14
WAAS GUS Signal Generator User Guide Rev 1
Chapter 2
Minimum Connections
When installed in a GUS, the Signal Generator requires the following connections:
AC Power - to the local mains supply to power the Signal Generator
L1 and/or L5 CMP - Comparator Message Processor as the WAAS message source
L1 and/or L5 WMP - WAAS Message Processor as the Signal Generator control terminal
10 MHz In - from the System 10 MHz Reference Source
1 PPS In - from the System 1 PPS Reference Source
L1 and/or L5 IF Output - to the Satellite Uplink path as the main Signal Generator output signal
L1 and/or L5 RF Output - to the local Signal Generator signal monitoring facility
All of the above connections are described in more detail in Chapter 3, Setup Considerations.
To demonstrate and/or experiment with signals generated by the Signal Generator in a test environment, outside of
the GUS, refer to the setup shown in Figure 4 on Page 16. Additional information on using the Signal Generator in
a test environment can be found in the WAAS SIGGEN GUI User Guide (NovAtel Document D25548) and
WAAS SIGGEN UDSM User Guide (NovAtel Document D25598).
WAAS GUS Signal Generator User Guide Rev 1
15
Chapter 2
Minimum Connections
Figure 4 displays how you might typically set up the Signal Generator to test the signal.
Figure 4: Signal Generator Setup Example
Reference
Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
WAAS GUS Signal Generator (NovAtel P/N 1020347)
WAAS G-III Receiver (NovAtel P/N 01018740)
10 MHz Low Noise OCXO Reference Oscillator
Personal Computer (PC)
Off-the-Shelf USB to RS-232 Adapter
Data Source Module (NovAtel P/N 01020346)
Externally Powered GPS Antenna
50 Ohm 3:1 RF Combiner, SMA
50 dB SMA Coaxial Attenuators, 50 ohm
SMA Coaxial DC-block (the WAAS G-III Receiver RF1 In outputs DC power by default)
DB-9 Serial Cable
USB Cable Type-A to micro-USB (NovAtel P/N 60723119)
50 ohm Coaxial Cable, Male TNC to Male SMA (NovAtel P/N 60423064)
50 ohm Coaxial Cable, Male Type-N TNC to Male SMA
120 VAC Power Cable (NovAtel P/N 60723070)
50 ohm Coaxial Cable, Male TNC to Male TNC
CAT-5 Ethernet Cable
Local Area Network
19
Gain Element (either an amplifier or an attenuator)1
1. To guarantee the noise power is between -152 dBm/Hz and -132 dBm/Hz at the input to the receiver.
The normal tracking range of the receiver is for CNos between 30 dB/Hz and 60 dB/Hz.
16
WAAS GUS Signal Generator User Guide Rev 1
Minimum Connections
Chapter 2
An example configuration would result from the following steps (see also Figure 4):
1.
Place the Signal Generator on a suitable work surface.
2.
Connect the 1PPS In port on the Signal Generator to the 1PPS Out port on the Receiver with
interconnecting coaxial cable. A typical coaxial cable is shown in Figure 5.
Figure 5: Coaxial Cable
3.
Connect the 10 MHz In port on the Signal Generator to the 10 MHz external reference with an
interconnecting coaxial cable.
4.
Connect the 10 MHz In port on the Receiver to the 10 MHz Out port on the Signal Generator with an
interconnecting coaxial cable.
5.
Connect the L1 and L5 CMP ports and the L1 and L5 Code 1PPS Out ports on the Signal Generator to
their respective Data Source Modules. Set the Data Source Modules L1 and L5 selector switches
respectively.
6.
Connect the Data Source Modules to the Test PC using the USB cables supplied with the Data Source.
7.
Connect the L1 and L5 RF OUT ports on the Signal Generator to attenuators which are then connected to
inputs of the RF Combiner using interconnecting coaxial cables. The attenuators should be selected so that
the signal power at the receiver input is between -105 to -90 dBm given an input noise power density to the
receiver of -150 dBm/Hz. (Typical attenuator vales are approximately 50dB.)
8.
Connect a Powered GPS Antenna to a LNA which is then connected to the input of the RF Combiner using
interconnecting coaxial cables. The total gain due to the antenna LNA, cable losses, combiner and any
external LNA should be approximately +20 dB or equivalently the noise power provided at the receiver
input, accounting for cascaded gain and noise figure, should be approximately -150 dBm/Hz.
9.
Connect the output of the RF Combiner to a DC Block which is then connected to the RF1 In of the
Receiver using interconnecting coaxial cables.
10. Connect the L1 and L5 WMP ports on the Signal Generator to a serial port on your PC with serial data
cables.
11. Connect the Data port on the Receiver to the same LAN that your Test PC is connected to using a network
cable.
12. Connect AC power to the power input port on the back of the Signal Generator using the supplied power
cable. Similarly, power the receiver and ensure your PCs are powered.
13. Press the power switch on the back of the Signal Generator, see Figure 6. The Power LED on the front
panel glows green while power is applied.
Figure 6: Power Switch
14. Control the Signal Generator using the Signal Generator GUI running on the Test PC.
WAAS GUS Signal Generator User Guide Rev 1
17
Chapter 2
Minimum Connections
15. Monitor your L1 and L5 data using available logs and commands from the Receiver through the Test PC.
The sections of Chapter 3, Setup Considerations on Page 19 give further details on steps #1 to #13 while Chapter
4, Operation on Page 24 helps with step #14. See the Signal Generator specific command and logs in Chapter 5,
Messages on Page 26. For other commands and logs available with the Receiver, please refer to its WAAS G-III
Reference Receiver user manual (OM-20000137).
18
WAAS GUS Signal Generator User Guide Rev 1
Chapter 3
Setup Considerations
The Signal Generator is a device that is intended for use in dry stable environments.

Observe ventilation requirements.
For proper ventilation, the Signal Generator requires clearance of 6 inches minimum on all sides, except for the rear
panel, which should remain clear from obstructions. Installations not meeting this requirement must ensure a
minimum forced air flow rate of 1 cu-m/minute through the ventilation holes of the unit.
3.1
Front Panel Functionality
As seen in Figure 7, there is a power LED that glows green when power is applied to the Signal Generator.
Figure 7: Signal Generator Front Panel
3.1.1
H/W Fault
This LED glows red when there is an internal hardware fault. It will cycle on and off at a 1 Hz rate when the 1PPS
input signal is lost. See also Section 5.1.4.6, Hardware Status Fields on Page 41.
3.1.2
10 MHz
This LED glows green when there is a 10 MHz reference present. The 10 MHz reference input level is in the range
+12 to +14 dBm and has an impedance of 50 ohms.
3.1.3
CW Mode
When the L1 CW Only or L5 CW Only switch is manually selected, the Signal Generator removes all modulation
from the L1 or L5 signal carrier respectively. The corresponding LED on the front panel glows red at the same time.
3.1.4
Transmit Inhibit (Tx INHIBIT)
This L1 or L5 Tx INHIBIT LED glows red if the L1 or L5 IF output is disabled. Incomplete L1 or L5 message data
transfer forces the unit to inhibit L1 or L5 signal transmission respectively for one second following the error.
This transmit inhibit function is controlled by a discrete signal that is applied via the Comparator input port. This
function is fail safe, so that if the control lines become open the transmission is inhibited.
WAAS GUS Signal Generator User Guide Rev 1
19
Chapter 3
3.1.5
Setup Considerations
Initiated Built in Test (IBIT)
IBIT is performed at power-up or upon a hardware reset. IBIT includes ROM and RAM testing. The front panel
specifies whether the L1 or L5 IBIT passed or failed. A green LED signifies an IBIT pass and an unlit LED
signifies an IBIT failure.
3.1.6
1PPS
The 1PPS LEDs are green and will cycle on and off at a 1 Hz rate to indicate the presence of a 1PPS output signal.
3.2
Rear Panel Functionality
The connections on the rear panel and their connector types are shown in Figure 8.
Figure 8: Close-up of Connectors on Rear Panel
Note: Where marked L1/L5, the top row of connectors is for the L1
signal and bottom row of connectors is for the L5 signal. Likewise
for the 10 MHz In/Out, the top connector is the Input and the bottom
is the Output.
Each connector is keyed to ensure that the cable can be inserted in only one way, to prevent damage to both the
Signal Generator and the cables. Furthermore, the connectors that are used to mate the cables to the Signal
Generator require careful insertion and removal. Observe the following when handling the cables.
• To insert a cable, make certain you are using the appropriate cable for the port - the serial cable has a
different connector (DB9) than the PPS cable (TNC), or the RF cable (N-Type) connectors.

3.2.1
DO NOT PULL DIRECTLY ON THE CABLES.
Power
After initial connection of the power supply to the Signal Generator and pressing the power switch on the back of
the unit (see Figure 8 above), the Power LED on the front of the unit (see Figure 7 on Page 19) glows green.
The Signal Generator requires an input supply voltage that comes from a normal power source of 120 volts AC at
60 Hz or 230 volts AC at 50 Hz through its 3-pin (hot, neutral and ground) power connector.

20
For safety reasons, ensure the 3-pin AC power plug is connected to a properly grounded AC
mains supply.
WAAS GUS Signal Generator User Guide Rev 1
Setup Considerations
Chapter 3
The AC Power Connector on the Signal Generator contains two 5 x 20 mm, 2.5 A slow-blow fuses that can be
serviced as long as the Signal Generator is disconnected from power. Fuses are accessed by pressing the upper and
lower tabs of the integrated fuse holder located between the AC Power connector and ON/OFF Switch. Use only
Littelfuse ® P/N 021802.5MXP or equivalent.

Blown fuses usually indicate that the internal hardware is malfunctioning. The hardware should
be returned to the factory for diagnosis and repair.
For a listing of the required input supply voltages, see Input/Output Connectors on Page 52. For more information
on the supplied 3-pin power cable, see Section A.1.2.1, Power Cable on Page 55.
3.2.2
CW Switch
The Signal Generator provides a L1 CW and a L5 CW toggle switch with a mechanical latching mechanism which
remove all modulation from the L1 IF and RF or L5 IF and RF carriers respectively.
3.2.3
Ground Screw
The available length of the stud is 3/8”. The stud is an 8-32 thread.
3.2.4
CMP and WMP
Each Signal Generator has independent command and status interfaces, and communicates over this interface with
a host computer (WAAS Message Processor - WMP). Similarly, the message interface for each Signal Generator is
independent, and communicates with a message generator (the Comparator Message Processor - CMP).
The Signal Generator is capable of L1 or L5 communications via two ports, L1 WMP and L5 WMP respectively.
3.2.5
Code PPS Output
The L1 and L5 Code PPS Out ports allow synchronization of external test equipment with the modulated L1 or L5
signal available respectively.
3.2.6
1PPS In
The 1PPS level is an active low pulse with TTL levels driving an input impedance of 3 k.. It is also factory
configurable to use active high pulses and/or a 50 AC coupled input impedance.
The pulse width of the 1PPS update is 200 microseconds nominally with a repetition rate of 1PPS. The high to low
transition is the reference edge. The high to low transition time is 5 ns or less. The high to low transition jitter with
respect to the 10 MHz is 1 ns or less.
Use of an external 50 ohm feed-thru terminator is recommended for factory default configuration.
For further information on the electrical specifications or connector type for the 1PPS In port, please see Input/
Output Connectors on Page 52.
3.2.7
10 MHz In and 10 MHz Out
There are two reference signal TNC connectors on the back of the Signal Generator for 10 MHz In and 10 MHz
Out.
The Signal Generator contains a detection mechanism and will use a 10 MHz reference signal when provided. In
the absence of an external 10 MHz reference signal, the signal generator will use its own internal 10 MHz OCXO.
Proper operation of the Signal Generator requires that the performance of the 10 MHz reference signal have the
characteristics provided in Table 1 below.
Table 1: External Reference Characteristics
Frequency
10 MHz
Amplitude
13 dBm ± 1 dBm
WAAS GUS Signal Generator User Guide Rev 1
21
Chapter 3
Setup Considerations
Impedance
50 ohms
Offset from Carrier Phase Noise
Phase Noise
1 Hz
<-100 dBc/Hz
10 Hz
<-130 dBc/Hz
100 Hz
<-145 dBc/Hz
1000 Hz
<-150 dBc/Hz
10,000 Hz
<-154 dBc/Hz
100,000Hz
<-154 dBc/Hz
±5 x 10-13
Accuracy
The 10 MHz output is buffered from the current system reference signal which may be the Signal Generator’s
internal OCXO or an external 10 MHz input. Its output amplitude is in the range 0 to +6 dBm and its output
impedance is 50 ohms.
For further information on the signals or connector type for the 10 MHz In and 10 MHz Out ports, please see Input/
Output Connectors on Page 52.
3.2.8
RF Out
The L1 and L5 RF Out connectors provide Radio Frequency (RF) signals from the Signal Generator.
The Signal Generator contains RF circuits to modulate and convert the digital In-Phase and Quadrature (I and Q)
data streams to an RF signal spectrum.
The nominal level of the RF Output of the Signal Generator is -50 dBm. The default frequency of the L1 RF Output
is 1227.6 MHz and can be user configured for an alternate output frequency of 1575.42 MHz. The default
frequency of the L5 RF Output is 1176.45 MHz and can be user configured for an alternate output frequency of
1227.6 MHz.
The Signal Generator L1 RF output is BPSK or QPSK modulated at a 1.023 MHz chip rate. The L5 RF output
modulation chip rate is 10.23 MHz. The RF output modulator phase on accuracy is within ±3 degrees.
For further information on the signals or connector type for the RF Out connectors, please see Input/Output
Connectors on Page 52.
3.2.9
IF Out
The L1 and L5 IF Out connectors provide a 70 MHz Intermediate Frequency (IF) signals from the Signal Generator.
It is normally used to provide L1 and L5 signals that are unconverted and uplinked to the GEO satellite at the
appropriate C band frequencies.
The signal amplitude is within the range -20 dBm ± 1.0 dB for any specified I/Q configuration. The signal
amplitude is stable to within 0.25 dB over an ambient operating temperature of 15°C to 25°C. After a warmup
period of 1 hour, the L1 IF signal amplitude is stable to within 0.25 dB over a 24 hour period at a constant ambient
temperature.
The factory configurable L1 signal (2, 4 or 22 MHz) is filtered by IF filters having the characteristics described in
Table 2.
Table 2: L1 IF Bandwidth Requirements
22
Nominal Bandwidth
3 dB Bandwidth
40 dB Bandwidth
2 MHz
> 1.9 MHz
< 4.25 MHz
4 MHz
> 4 MHz
< 11.2 MHz
22 MHz
> 22 MHz
< 28 MHz
WAAS GUS Signal Generator User Guide Rev 1
Setup Considerations
Chapter 3
The IF output has the phase noise characteristic shown in Table 3.
Table 3: IF Output Phase Noise
Offset from Carrier
Phase Noise (<)
1 Hz
-65 dBc/Hz
10 Hz
-85 dBc/Hz
100 Hz
-90 dBc/Hz
1 KHz
-95 dBc/Hz
10 KHz
-100 dBc/Hz
100 KHz
-108 dBc/Hz
The L1 CW Only switch forces the unit to remove all modulation from the signal carrier (I and Q signals both
forced to zero).
Disabling of the L1 output signal from the Signal Generator occurs under specific operating conditions identified in
Section 5.2, Error Handling on Page 44.
The L5 signal is filtered with a 22 MHz IF filter having the characteristics described in Table 4.
Table 4: L5 IF Bandwidth Requirements
Nominal Bandwidth
22 MHz
3 dB Bandwidth
> 22 MHz
40 dB Bandwidth
< 28 MHz
The L5 CW Only switch forces the unit to remove all modulation from the signal carrier (I and Q signals both
forced to zero).
The output impedance for the L1 and L5 IF Output is 50 Ohms.
WAAS GUS Signal Generator User Guide Rev 1
23
Chapter 4
Operation
Before operating the Signal Generator for the first time, ensure that you have followed the installation instructions
of Chapter 2, Minimum Connections on Page 15 and Chapter 3, Setup Considerations on Page 19. The following
instructions are based on a configuration such as that shown in “Signal Generator Setup Example” on page 16. It is
assumed that a personal computer is used during the initial operation and testing for greater ease and versatility.
4.1
Communications with the Signal Generator
Communication with the Signal Generator is straightforward, and consists of issuing commands through the WMP
communication ports from an external serial communications device. This could be either a terminal or a PC that is
directly connected to the Signal Generator serial port using an extension cable. For information about commands
and logs that are useful for basic operation of the Signal Generator, please see Chapter 5, Messages on Page 26.
4.1.1
Serial Port Default Settings
The Signal Generator communicates with your PC or terminal via the communication ports. For communication to
occur, both the Signal Generator and the operator interface have to be configured properly. The Signal Generator
data ports’ settings are as follows:
• 19200 bps, odd parity, 8 data bits, 1 stop bit, cts/rts handshaking, echo off
4.1.2
Communicating Using a Remote Terminal
One method of communicating with the Signal Generator is through a remote terminal. The Signal Generator
allows proper RS232 interface with your data terminal. To communicate with the terminal, the Signal Generator
requires the RX, TX, RTS, CTS and GND lines to be used. Ensure that the terminal’s communications set-up
matches the Signal Generator’s RS232 protocol.
4.1.3
Communicating Using a Personal Computer
A PC can be set up to emulate a remote terminal as well as provide the added flexibility of creating multiplecommand batch files and data logging storage files. Any standard communications software package that emulates
a terminal can be used to establish bidirectional communications with the Signal Generator. No particular terminal
type is assured. All data is sent as raw characters.
You can create command batch files using any text editor; these can then be directed to the data port that is
connected to the Signal Generator using a communications software package. This is discussed later in this chapter.
4.2
Message Control and Data Lines
The signal generator will modulate CMP messages onto the carrier if a complete CMP message is received in the
period between 20 ms and 980 ms after the respective L1 1 PPS or L5 1 PPS pulse.

Nominal GUS operation can use the reference 1 PPS to trigger the transmission of a CMP message
as the L1 1 PPS and L5 1 PPS pulses should be in advance of the external 1 PPS by about 130 ms.
The Message Interface provides the necessary control and data lines to allow downloading of data symbols from the
CMP to the Signal Generator. These lines are:
• MSGRDY from CMP to Signal Generator
• MSGCLK from Signal Generator to CMP
• MSGDATA from CMP to Signal Generator
After a compared message is stored in the Comparator output buffer, the Comparator sets the Message Ready flag
to the Signal Generator.
24
WAAS GUS Signal Generator User Guide Rev 1
Operation
Chapter 4
The Message Ready signal enables the Signal Generator internal 1 MHz clock (period 1 ms) which is then returned
to the Comparator.
The Comparator counts 500 clocks and resets the Message Ready flag after the 500th clock. For each clock, the
Comparator transfers each data bit from its output buffer on the leading edge, and the Signal Generator samples the
data bit on the trailing edge. The 500 bits of data are then transferred from the CMP to the Signal Generator at the 1
MHz rate. The entire transfer takes 500 s or 1/2 ms. The Signal Generator buffers each L1 and L5 500 SPS
message from the CMP.
If quadrature (Q) data is enabled on the L1 or L5 interface, a second set of 500 bits must be provided by the
Comparator for that interface as the Q data. If the second set of 500 bits is not provided, no data shall be transmitted
and the output of both the I and Q shall be inhibited. If only in-phase (I) data is enabled and a second set of 500 bits
is provided, the second set of 500 bits shall be discarded, however, the first set of 500 bits shall be transmitted
normally as the I data.
After MSGRDY has been asserted, the Signal Generator sends its first clock within 1 microsecond of the assertion.
After the 500th clock goes low, the MSGRDY should not be reasserted until after another 4 microseconds. The
interface timing is shown in Figure 9.
Figure 9: RS-485 Symbol Timing Diagram
4.2.1
Other Control Lines
Two other control lines exist on the Message Interface. These are:
• RESET from CMP to Signal Generator
• TX INH from CMP to Signal Generator
If the RESET line is high, the Signal Generator hardware undergoes a hard reset. The Signal Generator is rebooted
to power-up state after the RESET line is de-asserted. Note, the L1 and L5 operations are independent.
If the TX INH line is high, the Signal Generator IF output switch opens, causing the IF output signal to cease. The
RF output is not switched.
WAAS GUS Signal Generator User Guide Rev 1
25
Chapter 5
5.1
Messages
WMP Message Structure
Command and status messages are exchanged between the WMP and the Signal Generator using a RS-232 link.
Both command and status messages are encapsulated in a fixed length packet. This packet contains a
synchronization field, a L1/L5 indication field, message data fields and a CRC field for reliable packet transfer.
Table 5 shows the format of a message packet. Binary messages (command or status) are received by the Signal
Generator in byte order [0] through [35]. The Signal Generator swaps these bytes as necessary in order to recover
the original data fields. The tables shown in this chapter indicate the order in which bytes are received and
transmitted by the Signal Generator.
Table 5: Packet Format
5.1.1
Field
Bytes
Byte Position
Description
1
4
Byte [0:3]
Packet Synchronization Bytes Field
(start of packet)
2
1
Byte [4:4]
L1/L5 Indication Field
3
29
Byte [5:33]
Command Message Payload Fields or
Status Message Payload Fields.
4
2
Byte [34:35]
16 bit CRC Field.
Packet Synchronization Field
The packet synchronization field consists of four (4) bytes containing the hex value 0xAA5555AA. The Signal
Generator looks for these synchronization bytes and interprets them to be the start of a new packet. Status messages
transmitted to the WMP also have these synchronization bytes encoded to the hex value 0xAA5555AA. Table 6
shows the Packet Synchronization field. Table 7 shows the Packet Synchronization field byte and bit order.
Table 6: Packet Synchronization Field
Field
Bytes
Byte Position
1
4
Byte [0:3]
Description
Start of packet
Value
0xAA5555AA
Table 7: Packet Synchronization Field Bit Format
Byte [0]
D7 - D0
Byte [1]
D15 - D8
Byte [2]
Byte [3]
D23 - D16
D31 - D25
D0 = LSB
0xAA
5.1.2
D31 = MSB
0x55
0x55
0xAA
L1/L5 Indication Field
This field consists of one (1) byte containing the L1 or L5 indication flag. If a command is targeted for a L1 Signal
Generator then this byte contains the integer value 1, otherwise the integer value 5 is used to indicate a L5 target. If
a L1 signal generates a status message, this byte contains the integer value 1, otherwise the integer value 5 is used to
indicate a L5 signal generation source. Table 8 shows the L1/L5 Indication field. Table 9 on Page 27 shows the L1/
L5 Indication field bit order.
26
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
Table 8: L1/L5 Indication Field
Field
Bytes
2
1
Byte
Position
L1/L5
Destination
Byte [4:4]
L1=1, L5=5
WMP Destination
1=L1, L5=5
Table 9: L1/L5 Indication Bit Field
Byte [4]
D7
D6
D5
D4
D3
D2
D1
MSB
5.1.3
D0
LSB
Command Message
Table 10 shows the command message fields. The sections that follow indicate the data fields for all valid command
message identifiers.
Table 10: Command Message Fields
5.1.3.1
Field
Bytes
Byte Position
Description
3-1
1
Byte [5:5]
Command Message Identifier Field
3-2
1
Byte [6:6]
Control Command Data Field
3-3
1
Byte [7:7]
Symbol Rate Field
3-4
1
Byte [8:8]
Sub-Chip Field
3-5
2
Byte [9:10]
Code Chip Advance Field
3-6
2
Byte [11:12]
Symbol Advance Field
3-7
2
Byte [13:14]
3-8
2
Byte [15:16]
3-9
6
Byte [17:22]
Code Chip Rate Field
3-10
2
Byte [23:24]
Code Chip Rate Ramp Field
3-11
6
Byte [25:30]
Carrier Frequency Field
3-12
3
Byte [31:33]
Carrier Frequency Ramp Field
L1 I coder init G2 Field or
L5 I coder init XB(I) Field
L1 Q coder init G2 Field or
L5 Q coder init XB(Q) Field
Command Message Identifier Field
The Command Message Identifier field consists of one byte containing the command (instruction) message ID.
Based on this ID, the Signal Generator knows which data fields to interpret and what command needs to be
executed. Table 11 shows the Command Message Identifier byte field and bit order. Table 12 on Page 28 shows the
Command Message Identifier bit fields.
WAAS GUS Signal Generator User Guide Rev 1
27
Chapter 5
Messages
Table 11: Command Message Identifier Field
Byte [5]
D7
D6
D5
D4
D3
D2
D1
MSB
D0
LSB
Table 12: Command Message Identifier Bit Fields
Command message
(WMP to Signal Generator)
Bit
5.1.3.2
Command Message
ID Field
D0
Control Command
0x01
D1
Initialization Command
0x02
D2
Code Chip Rate and Carrier
Frequency Command
0x04
D3
Reserved for future use
0x08
D4
Reset Command
0x10
D5
Reserved for future use
0x20
D6
Reserved for future use
0x40
D7
Reserved for future use
0x80
Control Command
The Control Command provides for synchronous initialization of the L1 I and Q C/A code Generator states or the
L5 I and Q XB code Generator states, code modulation, symbol modulation, I channel modulation or Q channel
modulation. Upon receiving this command, the coder commences execution at the occurrence of the next 1-PPS
update pulse. If a valid Initialization Command was not received prior to receiving this command, this command is
not executed and the status message indicates the error. The Control command packet contains one byte of data.
Table 13 on Page 28 shows the L1/L5 Control Command byte field and bit order. Table 13 below shows the L1/L5
Control Command bit fields. This command must be preceded by an Initialization command to ensure that the I and
Q coders have been reset, initialized and advanced to the correct state.
Table 13: L1/L5 Control Command Bit Fields
Bit
28
Description
Range
Purpose
D0
Initialize Range
0-1
1 = Start coders at next valid Reference 1PPS
pulse
D1
Disable PRN Code (I)
0-1
1 = Coder output not used in modulation
D2
Disable Message (I)
0-1
1 = Symbol not used in modulation
D3
BPSK/QPSK Modulation
Mode Select
0-1
D4
Disable NH/Manchester (Q)
0-1
1=Disable NH code for dataless operation and
Manchester Code for data operation
D5
Disable NH/Manchester (I)
0-1
1=Disable NH code for dataless operation and
Manchester Code on data for L5 (not used for
L1 I data)
D6
Disable Message (Q)
0-1
1=Symbol not used in modulation
D7
Disable PRN Code (Q)
0-1
1=Coder output not used in modulation
0 = BPSK
1 = QPSK
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
Table 14: L1/L5 Control Command Field
Byte [6]
D7
D6
D5
D4
D3
D2
D1
D0
MSB
LSB
INITIALIZE RANGE FIELD
If this field (flag) is set, the Signal Generator, upon receiving the next 1-PPS pulse, starts the I and Q coders.
DISABLE PRN CODE (I) FIELD
If this field (flag) is set, the Signal Generator does not use the I PRN codes in modulation.
DISABLE MESSAGE (I) FIELD
If this field (flag) is set, the Signal Generator does not use the I message symbols in modulation.
SELECT BPSK OR QPSK MODULATION MODE FIELD
If this field (flag) is set, the Signal Generator operates in the QPSK mode of modulation. If this field is not set, the
Signal Generator operates in the BPSK mode of modulation.
DISABLE NH/MANCHESTER (Q) FIELD
If this field (flag) is set, the Signal Generator disables the NH code for dataless operation or Manchester Code for
data operation.
DISABLE NH/MANCHESTER (I) FIELD
If this field (flag) is set, the Signal Generator disables the NH code for dataless operation or for the L5 I channel
signal only, the Manchester Code for data operation. (Note that Manchester coding is not used on the L1 I channel
signal).
DISABLE MESSAGE (Q) FIELD
If this field (flag) is set, the Signal Generator does not use the Q message symbols in modulation.
DISABLE PRN CODE (Q) FIELD
If this field (flag) is set, the Signal Generator does not use the Q PRN codes in modulation.
For clarity, the I and Q channel modulation formats which result from different combinations of control commands
are tabulated below. Note that the I channel is always active so its data format does not depend on the D3 bit.
Table 15: Resulting I Modulation Format
D3
D1
D5
D2
PRN Code
N/A
0
0
0
Enable
N/A
0
0
1
Enable
N/A
0
1
0
N/A
0
1
N/A
1
0
Manchester
Code
L5 Enable
NeumannHoffman
Code
Symbols
Disable
Enable
Disable
Enable
Disable
Enable
Disable
Disable
Enable
1
Enable
Disable
Disable
Disable
0
Disable
Disable
Enable
WAAS GUS Signal Generator User Guide Rev 1
L1 Disable
L5 Enable
L1 Disable
29
Chapter 5
Messages
D3
D1
D5
D2
PRN Code
Manchester
Code
NeumannHoffman
Code
Symbols
N/A
1
0
1
Disable
Disable
Enable
Disable
N/A
1
1
0
Disable
Disable
Disable
Enable
N/A
1
1
1
Disable
Disable
Disable
Disable
Table 16: Resulting Q Modulation Format
D3
5.1.3.3
D7
D4
D6
PRN Code
Manchester
Code
NeumannHoffman
Code
Symbols
1
0
0
0
Enable
Enable
Disable
Enable
1
0
0
1
Enable
Disable
Enable
Disable
1
0
1
0
Enable
Disable
Disable
Enable
1
0
1
1
Enable
Disable
Disable
Disable
1
1
0
0
Disable
Enable
Disable
Enable
1
1
0
1
Disable
Disable
Enable
Disable
1
1
1
0
Disable
Disable
Disable
Enable
1
1
1
1
Disable
Disable
Disable
Disable
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Initialization Command
This command specifies the initial range (modulo 1 second) value to be used by the Signal Generator. Table 17
shows the initialization data fields for an L1 configured Signal Generator. Table 18 on Page 31 shows the
initialization data fields for an L5 configured Signal Generator at 500 SPS.
Table 17: L1 Initialization Command Fields
Byte Position
Description
Value / Scale Factor
Byte [7]
Symbol Rate/RF
Configuration
0 or 128
Set to zero ‘0’
Byte [8]
Sub-Chip
0 – 255
Initial DDS Sub-Chip
Byte [9:10]
Code Chip Advance
0 – 1022
Initial Code Chip Advance
Byte [11:12]
Symbol Advance
and Symbol 1 ms epoch
Bits [0:14] = 0 – 499
Initial Symbol Advance
and Symbol 1 ms epoch
I coder init G2.
Byte [13:14]
Byte[13] = init bits 0-7
Byte[14] = init bits 8-9
30
Valid Range
Bit [15:15] = 0-1 (MSB)
G2(I) channel coder
initialization value at zero chip
count
WAAS GUS Signal Generator User Guide Rev 1
Messages
Byte Position
Chapter 5
Description
Valid Range
Value / Scale Factor
Q coder init G2.
Byte [15:16]
G2(Q) channel coder
initialization value at zero chip
Count. Set to zero if not used.
Byte[15] = init bits 0-7
Byte[16] = init bits 8-9
Table 18: L5 Initialization Command Fields 500 SPS
Byte Position
Description
Valid Range
Value / Scale Factor
Byte [7]
Symbol Rate/RF
Configuration
0 or 128
Set to zero ‘0’
Byte [8]
Sub-Chip
0 – 255
Initial Sub-Chip Load
Byte [9:10]
Code Chip Advance
0 – 10229
Initial Code Chip Advance
Symbol Advance
Bits [0:14] = 0 – 499
Initial Symbol Advance
and Symbol 1 ms epoch
Bit [15:15] = 0-1 (MSB)
and Symbol 1 ms epoch
Byte [11:12]
I coder init XB(I).
Byte [13:14]
XB(I) I channel coder
initialization value at zero
chip count.
Byte[13] = init bits 0-7
Byte[14] = init bits 8-12
Q coder init XB(Q).
Byte [15:16]
XB(Q) Q channel coder
initialization value at zero
chip count.
Byte[15] = init bits 0-7
Byte[16] = init bits 8-12
SYMBOL RATE FIELD/RF CONFIGURATION FIELD
The message symbol rate sets the Symbols per Second (SPS) bit. When 0, the symbol rate is 500 SPS. When 1, the
symbol rate is 1000 SPS (not currently supported—reserved for future use).
The RF Center frequency is set by the RF Center bit. When 0, the default RF frequency is chosen (1227.6 MHz for
L1 and 1176.45 MHz for L5). When 1, the alternate frequency is chosen (1575.42 MHz for L1 and 1227.6 MHz for
L5).
Table 19: Symbol Rate/RF Configuration Field
Byte [7]
D7
D6
D5
D4
D3
D2
D1
D0
MSB
LSB
RF
Center
SPS
WAAS GUS Signal Generator User Guide Rev 1
31
Chapter 5
Messages
SUB-CHIP FIELD
This value specifies the initial sub-chip phase to be loaded into the Code DDS in increments of 1/256 code chip.
Table 20 shows the Sub-Chip field byte and bit format.
Table 20: Sub-Chip Field
Byte [8]
D7
D6
D5
D4
D3
D2
D1
D0
MSB
LSB
CODE CHIP ADVANCE FIELD
This value specifies the initial code chip advance from zero chip count. Table 21 shows the Chip Advance field byte
and bit format.
Table 21: Code Chip Advance Field
LS Byte [9]
D7
D6
D5
D4
D3
MS Byte [10]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
SYMBOL ADVANCE FIELD
This value specifies the initial symbol epoch advance from zero epoch count. At 500 SPS, the symbol epoch is 2
ms, at 1000 SPS, the symbol epoch is 1 ms. Table 22 shows the Symbol Advance field bit format. If 500 SPS is
selected, the MSB indicates which 1 ms epoch is selected within the initial symbol epoch. A ‘0’ indicates that the
even 1 ms epoch is selected within the initial 2 ms symbol epoch. A ‘1’ indicates that the odd 1 ms epoch is selected
within the 2 ms symbol epoch.
Table 22: Symbol Advance Field
LS Byte [9]
D7
D6
D5
D4
D3
MS Byte [10]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
L1 I CHANNEL G2 CODER INITIALIZATION FIELD
This field contains the initial state (10 bits) of the L1 I Channel G2 code generator. See Table 23 for the I channel
G2 coder initialization field bit format.
Table 23: L1 I Channel G2 Coder Initialization Field
LS Byte [13]
D7
G2I(7)
32
D6
(6)
D5
(5)
D4
(4)
D3
(3)
MS Byte [14]
D2
(2)
D1
(1)
D0
-
LSB
MSB
G2I(0)
-
-
-
-
-
-
D9
D8
-
-
-
-
-
G2I(9)
G2I(8)
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
L1 Q CHANNEL G2 CODER INITIALIZATION FIELD
This field contains the initial state (10 bits) of the L1 Q Channel G2 code generator. If this field is set to zero, then
the Q Channel G2 coder does not participate in modulation. See Table 24 on Page 33 for the Q channel G2 coder
initialization field bit format.
Table 24: L1 Q Channel G2 Coder Initialization Field
LS Byte [15]
D7
G2Q(7)
D6
D5
(6)
D4
(5)
(4)
D3
(3)
MS Byte [16]
D2
(2)
D1
(1)
D0
-
LSB
MSB
G2Q(0)
-
-
-
-
-
-
D9
D8
-
-
-
-
-
G2Q(9)
G2Q(8)
L5 I CODER INIT XB(I) FIELD
This field contains the initial state (13 bits) of the L5 I Channel XB(I) code generator. See Table 25 for the I channel
XB(I) coder initialization field bit format.
Table 25: L5 I Channel XB(I) Coder Initialization Field
LS Byte [13]
D7
XBI(7)
D6
(6)
D5
(5)
D4
(4)
D3
D2
(3)
(2)
MS Byte [14]
D1
(1)
D0
-
LSB
MSB
XBI(0)
-
-
-
D12
D11
-
-
XBI(12) 11
D10
D9
D8
10
9
XBI(8)
L5 Q CODER INIT XB(Q) FIELD
This field contains the initial state (13 bits) of the L5 Q Channel XB(Q) code generator. If this field is set to zero,
the Q Channel XB(Q) coder does not participate in modulation. Table 26 shows the byte and bit ordering for the Q
channel XB(Q) coder initialization field.
Table 26: L5 Q Channel XB(Q) Coder Initialization Field
LS Byte [15]
D7
XBQ(7)
5.1.3.4
D6
(6)
D5
(5)
D4
(4)
D3
(3)
D2
(2)
MS Byte [16]
D1
(1)
D0
-
LSB
MSB
XBQ(0) -
-
-
D12
D11
-
-
XBQ(12) 11
D10
D9
D8
10
9
XBQ(8)
Code Chip Rate and Carrier Frequency Command
The Code Chip Rate and Carrier Frequency Command specifies in absolute terms, the new Code Chip Rate and
Carrier Frequency (for either L1 or L5) to be assigned at the next 1PPS update pulse and the Code Chip Rate Ramp
and Carrier Frequency Ramp to be assigned at the update periods following the next 1PPS update pulse. The Code
Chip Ramp Rate or Carrier Frequency Ramp can be set to zero if no ramp update is to be performed every update
period (250 ms). If the Code Chip Ramp Rate is not zero, then the Code Chip Rate is adjusted by the Code Chip
Rate Ramp amount every 250 ms update period for three update periods following the next 1PPS. If the Carrier
Frequency Ramp is not zero, then the Carrier Frequency is adjusted by the Carrier Frequency Ramp amount every
250 ms update period for three update periods following the next 1PPS. Figure 10 on Page 35 shows the
application of three ramp values (fn) over 1 s application periods. The fourth one is overridden with the
application of the next Carrier Frequency value (fn+1). Table 27 on Page 34 shows all fields applicable to this
command.
WAAS GUS Signal Generator User Guide Rev 1
33
Chapter 5
Messages
Table 27: L1/L5 Code Chip Rate and Carrier Frequency Command Fields
Byte Position
Description
Valid Range
Scale Factor
Data Byte [17:22]
Code Chip
Rate
1.023 ±0.25/1540 Mcps (L1)
Data Byte [23:24]
Code Chip
Rate Ramp
±8.525 × 10-6 cps/250 ms (L1)
Data Byte [25:30]
Carrier
Frequency
70 ±0.25 MHz
LSB = 300 x 2-48 MHz
Data Byte [31:33]
Carrier
Frequency
Ramp
±0.025 Hz/250 ms
LSB = 300 x 2-50 MHz/250 ms
LSB = 75 x 2-48 Mcps
10.23 ±0.25/115 Mcps (L5)
LSB = 75 x 2-50 Mcps/250 ms
±8.525 × 10-5 cps/250 ms (L5)
CODE CHIP RATE FIELD
The Code Chip Rate field specifies the absolute initial code clock frequency. Table 28 shows the byte and bit
ordering for the Code Chip Rate field.
Table 28: Code Chip Rate Field
Byte [17]
Byte [18]
D7 – D0
Byte [19]
D15 – D8
D23 – D16
Byte [20]
Byte [21]
D31 – D24
Byte [22]
D39 – D32
D47 - D40
D0 = LSB
D47 = MSB
CODE CHIP RATE RAMP FIELD
This field is a 16 bit signed value (2’s complement) where D15, the most significant bit is the sign bit. See Table 29
for the Code Chip Rate Ramp field bit format.
Table 29: Code Chip Rate Ramp Field
LS Byte [23]
D7
D6
D5
D4
D3
D2
MS Byte [24]
D1
D0
-
D14
LSB
MSB(sign)
D13
D12
D11
D10
D9
D8
CARRIER FREQUENCY FIELD
The Carrier Frequency Command specifies in absolute terms, the new Carrier Frequency (for either L1 or L5) to be
assigned at the next 1PPS update pulse. See Table 30 for the Carrier Frequency field byte and bit order format.
Table 30: Carrier Frequency Field Bit Format
Byte [25]
LS Byte
D7 – D0
D0 = LSB
34
Byte [26]
D15 – D8
Byte [27]
Byte [28]
Byte [29]
Byte [30]
MS Byte
D23 – D16
D31 – D24
D39 – D32
D47 - D40
D47 = MSB
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
CARRIER FREQUENCY RAMP FIELD
This field is a 24 bit signed value (2’s complement) where the most significant bit (D23) is the sign bit. See Table 31
for the Carrier Frequency Ramp field byte and bit order format.
Table 31: Carrier Frequency Ramp Field Bit Format
7
6
Byte[31] – LS Byte
Byte[32]
Byte[33] – MS Byte
D7 – D0
D15 – D8
D23 – D16
5
4
3
2
1
0
15 14 13 12 11 10 9
D0 = LSB
8
23 22 21 20 19 18 17 16
D23 = MSB
Figure 10: Application of Frequency/Chipping Rate Ramp
fn
f n+fn
fn +2f n
f n+3f n
f n+1
fn +1+f n+1
f n+1 +2fn+1
f n+1+3fn +1
n
5.1.3.5
n+1
f n+2
n+2
Reset Command
The Reset Command allows the Signal Generator to be put into a reset state when operational. When this command
is received, the Signal Generator performs the actions as shown in Figure 11 on Page 36. There are no data fields
associated with this command.
5.1.3.6
Watchdog Timer
The watchdog performs a Signal Generator board reset if it is not serviced for 3 seconds due to a software failure.
The software services the watchdog as frequently as possible to prevent the watchdog from resetting the digital
board under normal operating conditions.
WAAS GUS Signal Generator User Guide Rev 1
35
Chapter 5
Messages
Figure 11: Input Command Flowchart
36
WAAS GUS Signal Generator User Guide Rev 1
Messages
5.1.4
Chapter 5
Status Message
The Status Message contains the status message fields. The L1/L5 Signal Generator sends the Status Message to the
WMP after every 1PPS update pulse. The status message contains the uplink range, the current setting of option
switches, any errors that may have occurred in the last 1 second epoch and hardware status. The status message is
transmitted from byte [0] through [33]. The WMP may need to swap bytes accordingly in order to recover the
original data field (prior to transmission by the Signal Generator). The following sections indicate the data fields for
a status message.
Table 32: Status Message Fields
Field
Bytes
Byte Position
Description
3-1
2
Byte [5:6]
Uplink Range Code Chip Sub-Phase
3-2
2
Byte [7:8]
Uplink Range Code Chip Counter
3-3
2
Byte [9:10]
Uplink Range Symbol Counter
3-4
1
Byte [11:11]
Switch Status
3-5
2
Byte [12:13]
Error Status
3-6
1
Byte [14:14]
Hardware Status
3-7
1
Byte [15:15]
For future use. Set to zero.
3-8
4
Byte [16:19]
3-9
4
Byte [20:23]
3-10
2
Byte [24:25]
Firmware Version Number
3-11
2
Byte [26:27]
FPGA Version Number
3-12
1
Byte [28:28]
Signal Generator State
3-13
5
Byte [29:33]
For future use. Set to zero.
Reset Command Second Epoch Counter
Range = 0 – (231-1)
Hardware Reset Second Epoch Counter
Range = 0 – (231-1)
Table 33: Uplink Range Fields
Data Byte Position
Byte [5:6]
5.1.4.1
Description
Uplink Range Code Chip Sub-Phase
Resolution = 1 x 2-16 code chip
Byte [7:8]
Uplink Range Code Counter
Byte [9:10]
Uplink Range Symbol Counter
Uplink Range Code Chip Sub-Phase Field
This field contains the sub-phase of the code chip latched, within the current 1 ms epoch, upon detection of a 1PPS
update pulse. Table 34 on Page 38 shows the Uplink Range Code Chip Sub-Phase field byte and bit order.
WAAS GUS Signal Generator User Guide Rev 1
37
Chapter 5
Messages
Table 34: Uplink Range Code Chip Sub-Phase Field
LS Byte [5]
D7
5.1.4.2
D6
D5
D4
D3
MS Byte [6]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Uplink Range Code Chip Counter Field
This field contains the code count latched, within the current 1 ms epoch, upon detection of a 1PPS update pulse.
Table 35 shows the Uplink Range Code Counter field byte and bit order.
Table 35: Uplink Range Code Chip Counter Field
LS Byte [7]
D7
5.1.4.3
D6
D5
D4
D3
MS Byte [8]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Uplink Range Symbol Counter Field
This field contains the symbol count latched, within the current 1 ms epoch, upon detection of a 1PPS update pulse.
At 500 SPS, the symbol counter epoch is 2 ms. At 1000 SPS, the symbol counter epoch is 1 ms. Table 36 shows the
Uplink Range Symbol Counter field byte and bit order. If 500 SPS is selected, the MSB indicates which 1 ms epoch
is selected within the initial symbol epoch. A ‘0’ indicates that the even 1 ms epoch is latched within the initial 2 ms
symbol epoch. A ‘1’ indicates that the odd 1 ms epoch is latched within the 2 ms symbol epoch.
Table 36: Uplink Range Symbol Counter Field
LS Byte [9]
D7
5.1.4.4
D6
D5
D4
D3
MS Byte [10]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Switch Status Fields
The Switch Status field contains the current state of all Signal Generator switches. The switch settings are polled
when the Status Message is created at the start of the current 1 second epoch. Table 37 shows the Switch Status field
byte and bit order. Table 38 on Page 38 shows the Switch Status bit fields.
Table 37: Switch Status Field
Byte [11]
D7
D6
D5
D4
D3
D2
D1
MSB
D0
LSB
Table 38: Switch Status Bit Fields
Bit
D0
38
Switch Status Description
TX Inhibit
Range
0 = Enable
1 = Disable
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
Bit
Switch Status Description
Range
0 = Enable
D1
IF Switch Position
D2
CW Mode only
D3-D7
Reserved for future use. Set to zero.
1 = Disable
0 = Not CW Mode
1 = CW Mode
TX INHIBIT FIELD
This flag indicates the TX Inhibit status of the Message interface. If a ‘1’, this flag indicates if the transmitter has
been disabled through the Message Interface. If a ‘0’ this flag indicates that the Message interface has not disabled
the transmitter.
IF SWITCH POSITION FIELD
This flag indicates the current setting of the IF switch. If a ‘1’, this flag indicates that the IF switch has been
disabled. If a ‘0’, this flag indicates that the IF switch is enabled.
CW MODE ONLY FIELD
This flag indicates the current setting of the CW Only mode Switch. If a ‘1’, this flag indicates that the CW Mode
Only Switch is closed and that the Signal Generator is in CW mode only. If a ‘0’, this flag indicates that the CW
Mode Only Switch is open and that the Signal Generator is not in CW mode
5.1.4.5
Error Status Fields
The Error Status field contains any errors that may have occurred during the last 1 second epoch. The Error Status
field bits are reset to zero after the status message is sent. Table 39 shows the Error Status field byte and bit order.
Table 40 on Page 39 shows the Error Status bit fields.
Table 39: Error Status Field
LS Byte [12]
D7
D6
D5
D4
D3
MS Byte [13]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Table 40: Error Status Bit Fields
Bit
Error Status Description
D0
CMP Data Error, see Section 5.2, Error Handling
on Page 44
D1
Update Data not complete at 1PPS
D2
Status Data not Complete at 1PPS
D3
Parity Error on Received Data
WAAS GUS Signal Generator User Guide Rev 1
Range
0 = No Error
1 = Error
0 = Complete
1 = Incomplete
0 = Complete
1 = Incomplete
0 = No Parity Error
1 = Parity Error
39
Chapter 5
Messages
Bit
Error Status Description
Range
0 = No Error
D4
Framing Error on Received Data
D5
Overrun Error on Received Data
D6
Receive Data Sync Error
D7
Receive Data CRC16 Error
D8
Invalid Field Value in Last Command Received
D9
Invalid Range Fields
D10-D15
Reserved for future use. Set to zero.
1 = Error
0 = No Error
1 = Error
0 = Valid Sync Byte
1 = No Valid Sync Byte
0 = Valid CRC Field
1 = No Valid CRC Field
0 = Valid Field Value
1 = Invalid Field Value
0 = Valid Range Fields
1 = Invalid Range Fields
CMP DATA ERROR FIELD
See Section 5.2, Error Handling on Page 44.
UPDATE DATA NOT COMPLETE AT 1PPS FIELD
If a ‘1’, this flag indicates that a command received during the previous 1 second epoch was incomplete.
STATUS DATA NOT COMPLETE AT 1PPS FIELD
If a ‘1’, this flag indicates that a status message was not transmitted completely during the previous 1-second epoch.
This flag is reset after the status message has been transmitted.
PARITY ERROR ON RECEIVED DATA FIELD
If a ‘1’, this flag indicates that the UART detected a parity error in one or more command bytes during the previous
1-second epoch. This flag is reset after the status message has been transmitted.
FRAMING ERROR ON RECEIVED DATA FIELD
If a ‘1’, this flag indicates that the UART detected a framing error in one or more command bytes during the
previous 1-second epoch. This flag is reset after the status message has been transmitted.
OVERRUN ERROR ON RECEIVED DATA FIELD
If a ‘1’, this flag indicates that the UART detected an overrun error in one or more command bytes during the
previous 1-second epoch. This flag is reset after the status message has been transmitted.
RECEIVE DATA SYNC ERROR FIELD
If a ‘1’, this flag indicates that the Signal Generator did not receive a valid sync byte in a command packet during
the previous 1-second epoch. This flag is reset after the status message has been transmitted.
RECEIVE DATA CRC ERROR FIELD
If a ‘1’, this flag indicates that the Signal Generator detected an invalid CRC field in a command packet during the
previous 1-second epoch. This flag is reset after the status message has been transmitted.
40
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
INVALID FIELD VALUE FIELD
If a ‘1’, this flag indicates that the Signal Generator detected an invalid field value in the last command received,
during the previous 1-second epoch. This flag is reset after the status message has been transmitted.
INVALID RANGE FIELDS FIELD
If a ‘1’, this flag indicates that the range fields contained in this status message are invalid and should not be used.
5.1.4.6
Hardware Status Fields
The Hardware Status field contains the current state of the Signal Generator hardware. The hardware is polled when
the Status Message is created at the start of the current 1 second epoch. Table 41 shows the Hardware Status field bit
order. Table 42 shows the Hardware Status bit fields.
Table 41: Hardware Status Field
Byte [14]
D7
D6
D5
D4
D3
D2
D1
MSB
D0
LSB
Table 42: Hardware Status Bit Fields
Bit
Hardware Status Description
D0
Reference 10 MHz Present
D1
Clock Circuit Fault
D2
RF Circuit Fault
D3
BPSK or QPSK Mode Selected
D4
Reserved for future use.
D5
Symbols Per Second 500
D6
Signal Generator Operational
D7
Reference 1PPS present
Range
0 = Not Present
1 = Present
0 = No Fault
1 = Fault
0 = No Fault
1 = Fault
0 = BPSK
1 = QPSK
0 = 500 SPS
1 = 1000 SPS
0 = Not Operational
1 = Operational
0 = Not Present
1 = Present
10 MHZ PRESENT FIELD
This flag indicates if the 10 MHz clock signal is present. If a ‘1’, then the 10 MHz signal is present. If a ‘0’, then the
10 MHz signal is absent.
CLOCK CIRCUIT FAULT FIELD
This flag indicates if the clock circuit board is faulty. If a ‘1’, then the clock circuit board is faulty. If a ‘0’, then the
clock circuit board is not faulty.
WAAS GUS Signal Generator User Guide Rev 1
41
Chapter 5
Messages
RF CIRCUIT FAULT FIELD
This flag indicates if the RF circuit board is faulty. If a ‘1’, then the RF circuit board is faulty. If a ‘0’, then the RF
circuit board is not faulty.
BPSK OR QPSK MODE SELECTED
This flag indicates the modulation mode selected, BPSK or QPSK. If set to '0', then BPSK modulation mode is
selected. If set to '1', then QPSK mode is selected. The value of this flag is determined by the BPSK/QPSK
Modulation Mode Select bit, see Table 13, L1/L5 Control Command Bit Fields on Page 28.
SYMBOLS PER SECOND FIELD
This flag indicates the hardware symbol rate. If a ‘0’, then the Signal Generator is processing 500 symbols per
second. The Symbol Rate field in the L5 Initialization Command determines the value of this flag, see Table 18, L5
Initialization Command Fields 500 SPS on Page 31.
SIGNAL GENERATOR OPERATIONAL
This flag indicates if the Signal Generator is operational and that Code Rate Commands and Carrier Frequency
Commands are accepted. If this bit is set to ‘0’, Code Rate Commands and Carrier Frequency Commands are not
applied. If this bit is set to ‘1’, the Signal Generator is operational and Code Rate Commands and Carrier Frequency
Commands are applied. This bit is only set to ‘0’ at power-up and after a Reset Command is received. It is set to ‘1’
after a Control Command is received and all internal calibrations have been performed.
REFERENCE 1PPS PRESENT FIELD
The flag indicates if the 1PPS reference is present. If this bit is set to ‘1’, the 1PPS signal is present. If this bit is set
to ‘0’, the 1PPS signal is not present.
5.1.4.7
Reset Command Second Epoch Counter
This field contains the number of one second epochs counted since the last hardware reset occurred or since the last
RESET command was received. The counter is started upon successful detection of an external 1PPS update pulse.
The range of this field is 0 – (231-1). The MSB is set to zero to prevent false detection of packet SYNC header
bytes. Table 43 shows the byte order and format for this field.
Table 43: Reset Command Second Epoch Counter
LS Byte [16]
D0 = LSB
Byte [17]
Byte [18]
LS Byte [19]
D31 = MSB = ‘0’
D7 – D0
D15 – D8
D23 – D16
D31 – D24
7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
5.1.4.8
Hardware Reset Second Epoch Counter
This field contains the number of one second epochs counted since the last hardware reset occurred. The counter is
started upon successful detection of an external 1PPS update pulse. The range of this field is 0 – (231-1). The MSB
is set to zero to prevent false detection of packet SYNC header bytes. Table 44 on Page 42 shows the byte order and
format for this field.
Table 44: Hardware Reset Second Epoch Counter
LS Byte [20]
D0 = LSB
Byte [21]
Byte [22]
LS Byte [23]
D31 = MSB = ‘0’
D7 – D0
D15 – D8
D23 – D16
D31 – D24
7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
42
WAAS GUS Signal Generator User Guide Rev 1
Messages
5.1.4.9
Chapter 5
Firmware Version Number
This field contains the firmware version number. The firmware version number consists of two parts, the revision
number (major) and the release (minor). Table 45 on Page 43 shows the byte order and format for this field.
Table 45: Firmware Version Number Field
LS Byte [24]
D7
5.1.4.10
D6
D5
D4
D3
MS Byte [25]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
FPGA Version Number
This field contains the FPGA version number. The FPGA version number consists of two parts, the revision number
(major) and the release (minor). Table 46 shows the byte order and format for this field.
Table 46: FPGA Version Number Field
LS Byte [26]
D7
5.1.4.11
D6
D5
D4
D3
MS Byte [27]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Signal Generator State
This field contains the state of the Signal Generator during the previous one second epoch. Table 47 shows the byte
order and format for this field. Table 48 on Page 43 shows the Signal Generator state values.
Table 47: Signal Generator State Field
Byte [28]
D7
D6
D5
D4
D3
D2
D1
MSB
D0
LSB
Table 48: Signal Generator State Value
State Value
Description
0
Invalid State Error. This indicates a software error.
1
RESET state
2
INITIALIZED state
3
CALIBRATION state
4
OPERATIONAL state
WAAS GUS Signal Generator User Guide Rev 1
43
Chapter 5
5.1.5
Messages
CRC-16/CCITT Checksum Field
A CRC-16/CCITT Cyclic Redundancy Check field is used to validate the received message to a high degree of
confidence that it was not corrupted during transmission. The sending system calculates the CRC-16 on all message
bytes excluding the CRC data bytes, and appends it to the message. The receiving system calculates the CRC-16 on
all message bytes received, excluding the CRC data bytes. The calculated CRC is compared with the received CRC.
If the calculated CRC does not match the received CRC, the received message is declared as corrupted. A corrupted
message is not used. Table 49 shows the CRC-16/CCITT field and Table 50 on Page 44 shows its bit format. The
characteristics for the CRC-16/CCITT are shown in Table 51 on Page 44.
Table 49: CRC-16/CCITT Checksum Field
Field
4
Bytes
2
Byte Position
Byte [34:35]
Description
Range
CRC16 Checksum
Hex 0000 – FFFF
Table 50: CRC-16/CCITT Checksum Field
LS Byte [34]
D7
D6
D5
D4
D3
MS Byte [35]
D2
D1
D0
D15
LSB
MSB
D14
D13
D12
D11
D10
D9
D8
Table 51: CRC-16-CCITT Characteristics
Name
5.2
CRC-16/CCITT
CRC Width
16 Bits
Polynomial
1021 = X16 + X12 + X5 + X0
Initial CRC Value
0xFFFF Hex
Input Bytes Reflected?
NO
Output CRC Result Reflected?
NO
Output XOR Value
0x0000
Single Bit Errors Detected
100%
Double Bit Errors Detected
100%
Odd Numbered Bit Errors Detected
100%
Burst Errors Shorter Than 16 Bits
100%
Burst Errors of Exactly 17 Bits
99.9968%
All Other Burst Errors
99.9984%
Error Handling
Table 52 shows the Signal Generator error conditions and their corresponding handling methods.
44
WAAS GUS Signal Generator User Guide Rev 1
Messages
Chapter 5
Table 52: Errors
Error Description
Handling Method
Notes
CMP message truncated
I and Q set to zero and
Transmitter disabled
Report status
CMP MSGRDY stuck high
I and Q set to zero and
Transmitter disabled
Report status
CMP MSGRDY stuck low
I and Q set to zero and
Transmitter disabled
Report status
MSGDATA not ready when needed
I and Q set to zero and
Transmitter disabled
Report status
WAAS GUS Signal Generator User Guide Rev 1
45
Chapter 6
Firmware Updates
As described in Chapter 1, the Signal Generator is comprised of two independent L1 and L5 generators. Each
digital card has the same firmware (program software). The firmware is stored in on-board, non-volatile memory,
which allows the Signal Generator's firmware to be updated in the field. Thus, updating firmware takes only a few
minutes instead of the several days which would be required if the Signal Generator had to be sent to a service
depot.
When updating to a higher revision level, you will need to transfer the new firmware to the appropriate card using
WinLoad, a Windows-based program. It is recommended that you use the most recent version of WinLoad
available.
Below is shown an outline of the procedure for updating your Signal Generator's firmware:
6.1
1.
Contact the NovAtel Customer Support (refer to Contact Information on Page 8 for contact options)
2.
Download update files
3.
Decompress files
4.
Run the firmware loading utility
Contacting the NovAtel Customer Support
The first step in updating the Signal Generator is to contact the NovAtel Customer Support using the contact
information on Page 8.
When you call, be sure to have the WAAS GUS Signal Generator's serial number and program revision level
available. This information is printed on the rear panel of the Signal Generator, as shown in Figure 12.
Figure 12: Serial Number and Version Label
You can also verify the information. First power up the Signal Generator and then communicate with it using your
custom interface to check the Signal Generator’s version. See also Section 5.1.4.9, Firmware Version Number on
Page 43.
After conferring with the NovAtel Customer Support to establish the required revision level, as well as the terms
and conditions of your firmware update, the NovAtel Customer Support will issue you with the latest firmware
when it is available.
If it is determined that you will be updating to a higher revision level with the use of the firmware loading utility,
the NovAtel Customer Support will confirm with you as to the procedures, files, and methods required for using
this utility. As the main utility and other necessary files are generally provided in a compressed file format, you will
also be given a file decompression password. The utility and update files are available from NovAtel Customer
Support.
46
WAAS GUS Signal Generator User Guide Rev 1
Firmware Updates
6.2
Chapter 6
Downloading the Files
Typically, there are three files required when performing firmware updates on a particular Signal Generator card:
• WINLOAD.EXE (the firmware loading utility program)
• [Application Firmware File Name].HEX (the Application firmware update file)
• [FPGA Firmware File Name].HEX (the FPGA firmware update file)
For example, the Signal Generator Application and FPGA firmware files might be named SIGGEN-2.10.HEX and
SIGGEN-FPGA-2.9.HEX respectively.
To proceed with your update, you will first need to download the appropriate files. Contact NovAtel Customer
Support: support@novatel.com.
The files are available in compressed, password-protected file format. The compressed form of the files may have
different names than the names discussed above; NovAtel Customer Support will advise you as to the exact names
of the files you need. As well, NovAtel Customer Support will provide you with a file de-compression password.
6.3
Decompressing the Files
After copying the compressed files to an appropriate directory on your computer, each file must be decompressed.
A Windows-based dialog is provided for password entry.
The self-extracting archive then generates the following files:
WinLoad.exe
WinLoad utility program
HowTo.txt
Instructions on how to use the WinLoad utility
WhatsNew.txt
Information on the changes made in the firmware since the last revision
[Application Firmware File Name].hex Application firmware version update file
[FPGA Firmware File Name].hex
6.4
FPGA firmware version update file
Running WinLoad
WinLoad is a Windows based program used to download firmware to Signal Generator cards. The main screen is
shown in Figure 13. Note that in order to load firmware on to the WAAS GUS Signal Generator, the following
hardware setup is required:
• Data Source Modules need to be connected to the L1 and L5 CMP ports and Code 1PPS Out ports. These
also have to be connected to the PC which will perform the firmware load, or at a minimum need to be
powered.
• The L1 and L5 WMP ports need to be connected to the PC which will perform the firmware load.
• A 1PPS signal needs to be provided into the 1PPS In port of the WAAS GUS Signal Generator.
Once these are in place, WinLoad can then be used to load firmware as described in the following sections.
WAAS GUS Signal Generator User Guide Rev 1
47
Chapter 6
Firmware Updates
Figure 13: Main Screen of WinLoad
9600
If you are running WinLoad for the first time you will need to make sure the file and communications settings are
correct.
6.4.1
Open a File to Download
From the file menu choose Open. Use the Open dialog to browse for your file, see Figure 14.
Figure 14: WinLoad’s Open Dialog
Once you have selected your file, the name should appear in the main display area and in the title bar, see Figure 15.
48
WAAS GUS Signal Generator User Guide Rev 1
Firmware Updates
Chapter 6
Figure 15: Open File in WinLoad
The Target Card ID field allows you to specify which Signal Generator card to update, see Table 53 below.
Table 53: Target Card Identification
Entry
0
6.4.1.1
Description
SigGen Digital Card
Communications Settings
To set the communications port and baud rate, select COM Settings from the Settings menu, see Figure 16. Choose
the port on your PC from the Com Port drop down list and the baud rate from the Download Baudrate drop down
list. The Download Baudrate can be set to 9600 or 115200 while the Connect Baudrate should be set to 9600.
Figure 16: COM Port Setup
WAAS GUS Signal Generator User Guide Rev 1
49
Chapter 6
6.4.2
Firmware Updates
Downloading firmware
To download firmware follow these steps:
1.
Set up the communications port as described in Communications Settings above.
2.
Select the file to download, see Open a File to Download on Page 48.
3.
Make sure the file path and file name are displayed in the main display area, see Figure 15 above.
4.
Click on the Write Flash button to download the firmware:
5.
While WinLoad searches for the card, power cycle the Signal Generator (turn it off and then on again).

You will only be able to access information from the card and download new firmware
during the first few seconds after power initiation.
6.
WinLoad should be able to locate the card and the hex file should start downloading.
7.
The Signal Generator should finish downloading and reset. The process is complete when “Done.” is
displayed in the main display area, see Figure 17.
Figure 17: Update Process Complete
9600
8.
Close WinLoad.
This completes the procedure required to update a Signal Generator.

50
The L1 and L5 firmware loads are independent of each other and Application and FPGA
firmware must be loaded individually for each.
WAAS GUS Signal Generator User Guide Rev 1
Appendix A
A.1
Technical Specifications
Signal Generator
PHYSICAL
Size
432 mm (17.0”) x 406 mm (16.0”) x 133 mm (5.2”)
Weight
9.8 kilograms (21.4 lb.)
MECHANICAL DRAWINGS
Figure 18: Signal Generator Dimensions
Dimensions are in millimeters.
WAAS GUS Signal Generator User Guide Rev 1
51
ENVIRONMENTAL
Operating Temperature
0° C to +50° C
Storage Temperature
-40°C to +85°C
Operating Humidity
10 to 80% non-condensing
Storage Humidity
0 to 95% non-condensing
INPUT/OUTPUT CONNECTORS
Input power connector - IEC 320-C14
3-pin power cord provided (for North American standard A/C)
100 to 240 VAC*
Power Input
Voltage
* Nominal power input voltage range to which an
additional 10% tolerance is assumed.
Frequency
47 to 63 Hz
Current
Ground Screw
0.2 A @ 230 VAC
VA
<75
Fuse Rating:
Glass 5x20 mm 2.5 A 250 VAC slow blow
(there are 2 of these)
Length of Stud
3/8”
Stud Thread
8-32
L1 WMP
DE9P Connector
L5 WMP
DE9P Connector
PPS Input
0.3 A @ 120 VAC
Connector
TNC female jack
Signal Description
A one-pulse-per-second normally high, active low
pulse (between 10 microsecond to 1 millisecond)
where the falling edge is the reference.
Level
Voltage
Connector
TNC female jack
Signal Description
A one-pulse-per-second normally high, active low 1
millisecond pulse where the falling edge is the
reference
L1 or L5 1PPS Output
52
Low < 0.80VDC
Voltage
High >2.0 VDC
Low < 0.4 VDC
Impedance
Open drain with 1k pullup
Resistor to +5 V
Level
L1 IF Output
High > 2.0 VDC
Connector
TNC female jack
Frequency
70.000 MHz
Bandwidth
22 MHz
Level
-20 dBm ±1 dB
Impedance
50 
VSWR
2:1 max at the center frequency
WAAS GUS Signal Generator User Guide Rev 1
L5 IF Output
Connector
TNC female jack
Frequency
70.000 MHz
Bandwidth
22 MHz
Level
-20 dBm ±1 dB
Impedance
50 
VSWR
2:1 max at the center frequency
Connector
Type N female jack
Frequency
L1 RF Output
10 MHz Input
10 MHz Output
Alternate: 1575.42 MHz (L1)
Bandwidth
22 MHz
Level
-50 dBm ±3 dB
Impedance
50 
VSWR
2:1 max at the center frequency
Connector
Type N female jack
Frequency
L5 RF Output
Default: 1227.6 MHz (L2)
Default: 1176.45 MHz (L5)
Alternate: 1227.6 MHz (L2)
Bandwidth
22 MHz
Level
-50 dBm ±3 dB
Impedance
50 
VSWR
2:1 max at the center frequency
Connector
TNC female jack
Sensitivity
13 ±1 dBm
Impedance
50 
Connector
TNC female jack
RF Output Power
3 ± 3 dBm
Impedance
50 
Phase Noise
(internal OCXO only)
@10 Hz
@100 Hz
@1 kHz
@10 kHz
Temperature Stability
(internal OCXO only)
Aging
(internal OCXO only)
WAAS GUS Signal Generator User Guide Rev 1
-125 dBc/Hz max
-155 dBc/Hz max.
-165 dBc/Hz max.
-165 dBc/Hz max.
±1 x 10-8 over operating temperature range
5 x 10-10 per day after 30 days operating (typical)
53
A.1.1
Connector Pin-Outs
Table 54 and Table 55 show details of the connector pin-outs on the Signal Generator.
Table 54: L1 and L5 WMP Connector Pin-Out Descriptions
Pin No.
Direction
Name
1
Reserved
2
Out
TxD
3
In
RxD
4
Reserved
5
GND
6
Reserved
7
In
CTS
8
Out
RTS
9
Reserved
Table 55: L1 and L5 CMP Connector Pin-Out Descriptions
Pin No.
Direction
Name
1
GND
2
Out
MSGCLKa
3
In
MSGRDYa
4
Reserved
5
In
MSGRDATAa
6
In
RESETa
7
GND
8
Reserved
9
In
TXINHb
10
11
Reserved
12
13
In
MSGDATAb
14
Out
MSGCLKb
15
Reserved
16
In
MSGRDYb
17
In
TXINHa
18
19
20
Reserved
21
22
In
RESETb
23
24
Reserved
25
54
WAAS GUS Signal Generator User Guide Rev 1
A.1.2
Cables
A.1.2.1
Power Cable
The power cable supplied with the Signal Generator connects from the Power Input port on the back of the Signal
Generator to an external power source (+100 to +240 VAC). An input voltage outside of this range may physically
damage the unit, voiding the warranty. The power supply automatically adapts its input power to the national power
source in the country of use as long as it is within the above range and you have an adapter for your local power
receptacle.
Figure 19: Power Cable
WAAS GUS Signal Generator User Guide Rev 1
55
OM-20000187 Rev 1
November 2019
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising