instruction manual - Boonton Electronics

instruction manual - Boonton Electronics
INSTRUCTION MANUAL
4240 SERIES
RF POWER METER
REV DATE 01/19/2011
MANUAL P/N 98406700A
CD P/N 98406799A
Wireless Telecom Group
25 EASTMANS ROAD, PARSIPPANY, NJ 07054
Telephone: 973-386-9696
Fax: 973-386-9191
Email: [email protected]
Web: www.wtcom.com
Boonton 4240 Series RF Power Meter
INSTRUCTION MANUAL, 4240 SERIES RF POWER METER
Revision date 01/19/2011
© Copyright in 2005-2011, by BOONTON Electronics, a subsidiary of the Wireless Telecom
Group, Inc.
Parsippany, NJ, USA. All rights reserved.
P/N 98406700A
This manual covers instrument serial numbers: 11001 and higher.
K-Connector® is a registered trademark of Anritsu Corporation.
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Contents
Boonton 4240 Series RF Power Meter
SAFETY SUMMARY
The following general safety precautions must be observed during all phases of operation and maintenance
of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this
manual violates safety standards of design, manufacture, and intended use of the instrument. Boonton
Electronics assumes no liability for the customer’s failure to comply with these requirements.
THE INSTRUMENT MUST BE GROUNDED
To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground.
The instrument is equipped with a NEMA three conductor, three prong power cable. The power cable must
either be plugged into an approved three-contact electrical outlet or used with a three-contact to a twocontact adapter with the (green) grounding wire firmly connected to an electrical ground in the power
outlet.
DO NOT OPERATE THE INSTRUMENT IN AN EXPLOSIVE ATMOSPHERE
Do not operate the instrument in the presence of flammable gases or fumes.
KEEP AWAY FROM LIVE CIRCUITS
Operating personnel must not remove instrument covers. Component replacement and internal adjustments
must be made by qualified maintenance personnel. Do not replace components with the power cable
connected. Under certain conditions dangerous voltages may exist even though the power cable was
removed, therefore; always disconnect power and discharge circuits before touching them.
DO NOT SERVICE OR ADJUST ALONE
Do not attempt internal service or adjustment unless another person, capable or rendering first aid and
resuscitation, is present.
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT
Do not install substitute parts or perform any unauthorized modifications or the instrument. Return the
instrument to Boonton Electronics for repair to ensure that the safety features are maintained.
Contents
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Boonton 4240 Series RF Power Meter
SAFETY SYMBOLS
This safety requirement symbol (located on the rear panel) has been adopted by the
International Electro-technical Commission, Document 66 (Central Office) 3, Paragraph
5.3, which directs that an instrument be so labeled if, for the correct use of the instrument,
it is necessary to refer to the instruction manual. In this case it is recommended that
reference be made to the instruction manual when connecting the instrument to the proper
power source. Verify that the correct fuse is installed for the power available.
The CAUTION symbol denotes a hazard. It calls attention to an operational procedure,
practice or instruction that, if not followed, could result in damage to or destruction of
part or all of the instrument and accessories. Do not proceed beyond a CAUTION symbol
until its conditions are fully understood and met.
The NOTE symbol is used to mark information which should be read. This information
can be very useful to the operating in dealing with the subject covered in this section.
The HINT symbol is used to identify additional comments which are outside of the
normal format of the manual, however can give the user additional information about the
subject.
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Contents
Boonton 4240 Series RF Power Meter
1.
General Information.............................................................................................. 1-1
1.1 Organization.......................................................................................................... 1-1
1.2 Description............................................................................................................ 1-2
1.3 Features................................................................................................................. 1-2
1.4 Accessories ........................................................................................................... 1-5
Standard ............................................................................................................... 1-5
Optional................................................................................................................ 1-5
Sensors ................................................................................................................. 1-5
1.5 Models, Options and Configurations .................................................................... 1-5
1.6 Specifications........................................................................................................ 1-6
SENSOR INPUTS ............................................................................................... 1-6
FEATURES ......................................................................................................... 1-6
UNCERTAINTIES .............................................................................................. 1-7
MEASUREMENT SYSTEM .............................................................................. 1-7
CALIBRATION SOURCE.................................................................................. 1-7
EXTERNAL INTERFACES ............................................................................... 1-8
PHYSICAL AND ENVIRONMENTAL CHARACTERISTICS ....................... 1-8
OTHER CHARACTERISTICS........................................................................... 1-9
REGULATORY CHARACTERISTICS ............................................................. 1-9
2.
Installation .............................................................................................................. 2-1
2.1 Unpacking & Repacking....................................................................................... 2-1
2.2 Power Requirements ............................................................................................. 2-2
2.3 Connections .......................................................................................................... 2-2
2.4 Preliminary Check ................................................................................................ 2-3
3.
Getting Started ....................................................................................................... 3-1
3.1 Organization.......................................................................................................... 3-1
3.2 Operating Controls, Indicators and Connections.................................................. 3-1
3.3 Operation .............................................................................................................. 3-6
3.3.1 Menu Key........................................................................................................ 3-9
3.3.2 Sensor Key. ................................................................................................... 3-15
3.3.3 FREQ Key..................................................................................................... 3-19
3.3.4 AVG Key. ..................................................................................................... 3-19
3.3.5 Zero/Cal Key (single key press operation). .................................................. 3-19
3.3.6 REL Level Key (single key press operation)................................................ 3-20
4.
Operation ................................................................................................................ 4-1
4.1 Sensor Calibration................................................................................................. 4-1
4.2 Zeroing.................................................................................................................. 4-1
Contents
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Boonton 4240 Series RF Power Meter
4.3 Dynamic Range..................................................................................................... 4-4
4.4 Filtering................................................................................................................. 4-5
4.5 Noise ..................................................................................................................... 4-5
4.6 Measurement Time ............................................................................................. 4-10
4.7 High Frequency Accuracy .................................................................................. 4-11
4.8 Waveform Sensitivity ......................................................................................... 4-12
4.9 Chart Recorder Operation................................................................................... 4-14
4.10 Bar Graph Operation......................................................................................... 4-14
5.
Remote Operation.................................................................................................. 5-1
5.1 GPIB Configuration.............................................................................................. 5-1
5.2 RS-232 Configuration........................................................................................... 5-1
5.3 SCPI Language ..................................................................................................... 5-2
5.3.1 SCPI Structure ............................................................................................... 5-2
5.3.2 Long and Short Form Keywords.................................................................... 5-2
5.3.3 Subsystem Numeric Suffixes......................................................................... 5-2
5.3.4 Colon Keyword Separators ............................................................................ 5-3
5.3.5 Command Arguments and Queries................................................................ 5-3
5.3.6 Semicolon Command Separators................................................................... 5-3
5.3.7 Command Terminators .................................................................................. 5-3
5.3.8 4240 Series SCPI Implementation ................................................................. 5-3
5.4 Basic Measurement Information........................................................................... 5-5
5.4.1 Service Request.............................................................................................. 5-5
5.5 SCPI Command Reference ................................................................................... 5-6
5.5.1 IEEE 488.2 Commands.................................................................................. 5-6
*CLS .................................................................................................................... 5-6
*ESE .................................................................................................................... 5-6
*ESR? .................................................................................................................. 5-7
*IDN?................................................................................................................... 5-7
*OPC.................................................................................................................... 5-7
*OPC? .................................................................................................................. 5-7
*OPT? .................................................................................................................. 5-8
*RST .................................................................................................................... 5-8
*SRE .................................................................................................................... 5-8
*STB? .................................................................................................................. 5-9
*TRG.................................................................................................................... 5-9
*TST?................................................................................................................... 5-9
*WAI.................................................................................................................... 5-9
5.5.2 CALCulate Subsystem................................................................................. 5-10
CALCulate:LIMit:CLEar[:IMMediate]............................................................. 5-10
CALCulate:LIMit:FAIL?................................................................................... 5-10
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Boonton 4240 Series RF Power Meter
CALCulate:LIMit:LOWer[:POWer] ................................................................. 5-10
CALCulate:LIMit:UPPer[:POWer] ................................................................... 5-11
CALCulate:LIMit:LOWer:STATe .................................................................... 5-11
CALCulate:LIMit:UPPer:STATe ...................................................................... 5-11
CALCulate:LIMit[:BOTH]:STATe................................................................... 5-11
CALCulate:MATH:ARGA................................................................................ 5-12
CALCulate:MATH:ARGB ................................................................................ 5-12
CALCulate:MATH:DATA? .............................................................................. 5-12
CALCulate:MATH:OPERator........................................................................... 5-12
CALCulate:MODe............................................................................................. 5-12
CALCulate:REFerence:COLLect ...................................................................... 5-13
CALCulate:REFerence:DATA .......................................................................... 5-13
CALCulate:REFerence:STATe ......................................................................... 5-13
CALCulate:STATe ............................................................................................ 5-13
CALCulate:UNITs............................................................................................. 5-13
5.5.3 CALibration Subsystem............................................................................... 5-14
CALibration:AUTOcal ...................................................................................... 5-14
CALibration:FIXedcal ....................................................................................... 5-14
CALibration:ZERO............................................................................................ 5-14
5.5.4 DISPlay Subsystem...................................................................................... 5-15
DISPlay:ACTive[?]............................................................................................ 5-15
DISPlay:CLEar .................................................................................................. 5-15
DISPlay:LIN:RESolution .................................................................................. 5-15
DISPlay:LOG:RESolution................................................................................. 5-15
DISPlay:LABel:MODE ..................................................................................... 5-15
DISPlay:LABel:TEXTA.................................................................................... 5-16
DISPlay:LABel:TEXTB .................................................................................... 5-16
DISPlay:LABel:TEXTC .................................................................................... 5-16
DISPlay:LABel:TEXTD.................................................................................... 5-16
5.5.5 FETCh Queries ............................................................................................ 5-17
FETCh:CW:POWer? ......................................................................................... 5-17
FETCh:KEY?..................................................................................................... 5-17
5.5.6 INITiate and ABORt Commands................................................................. 5-18
ABORt ............................................................................................................... 5-18
INITiate:CONTinuous ....................................................................................... 5-18
INITiate[:IMMediate[:ALL]] ............................................................................ 5-18
5.5.7 MEASure Queries........................................................................................ 5-19
MEASure:POWer? ............................................................................................ 5-19
MEASure:VOLTage? ........................................................................................ 5-19
5.5.8 MEMory Subsystem .................................................................................... 5-20
MEMory:SNSR:CF?.......................................................................................... 5-20
MEMory:SNSR:CWRG?................................................................................... 5-20
MEMory:SNSR:INFO? ..................................................................................... 5-20
MEMory:SYS:LOAD ........................................................................................ 5-20
MEMory:SYS:STORe ....................................................................................... 5-20
5.5.9 OUTPut Subsystem...................................................................................... 5-21
Contents
vii
Boonton 4240 Series RF Power Meter
OUTPut:LEVel[:POWer] .................................................................................. 5-21
OUTPut:SIGNal................................................................................................. 5-21
OUTPut:RECorder:FORCe ............................................................................... 5-21
OUTPut:RECorder:MAX .................................................................................. 5-21
OUTPut:RECorder:MIN.................................................................................... 5-21
OUTPut:RECorder:SOURce ............................................................................. 5-22
5.5.10 READ Queries ........................................................................................... 5-23
READ:CW:POWer? .......................................................................................... 5-23
5.5.11 SENSe Subsystem...................................................................................... 5-24
SENSe:CORRection:CALFactor....................................................................... 5-24
SENSe:CORRection:DCYCle ........................................................................... 5-24
SENSe:CORRection:FREQuency ..................................................................... 5-24
SENSe:CORRection:OFFSet............................................................................. 5-24
SENSe:FILTer:STATe ...................................................................................... 5-25
SENSe:FILTer:TIMe ......................................................................................... 5-25
5.5.12 STATus Commands................................................................................... 5-26
STATus:DEVice:CONDition? .......................................................................... 5-26
STATus:DEVice:ENABle ................................................................................. 5-26
STATus:DEVice:EVENt? ................................................................................. 5-27
STATus:DEVice:NTRansition .......................................................................... 5-27
STATus:DEVice:PTRansition........................................................................... 5-27
STATus:OPERation:CONDition? ..................................................................... 5-28
STATus:OPERation:ENABle............................................................................ 5-28
STATus:OPERation:EVENt? ............................................................................ 5-28
STATus:OPERation:NTRansition..................................................................... 5-29
STATus:OPERation:PTRansition...................................................................... 5-29
STATus:PRESet ................................................................................................ 5-29
STATus:QUEStionable:CONDition? ................................................................ 5-30
STATus:QUEStionable:ENABle....................................................................... 5-30
STATus:QUEStionable:EVENt?....................................................................... 5-30
STATus:QUEStionable:NTRansition................................................................ 5-31
STATus:QUEStionable:PTRansition ................................................................ 5-31
STATus:QUEStionable:CALibration:CONDition? .......................................... 5-31
STATus:QUEStionable:CALibration:ENABle ................................................. 5-32
STATus:QUEStionable:CALibration:EVENt? ................................................. 5-32
STATus:QUEStionable:CALibration:NTRansition .......................................... 5-32
STATus:QUEStionable:CALibration:PTRansition........................................... 5-32
5.5.13 SYSTem Subsystem................................................................................... 5-33
SYSTem:BEEP[:ENABle] ................................................................................ 5-33
SYSTem:BEEP:IMMediate............................................................................... 5-33
SYSTem:COMMunicate:GPIB:ADDRess ........................................................ 5-33
SYSTem:COMMunicate:GPIB:EOI.................................................................. 5-33
SYSTem:COMMunicate:GPIB:LISTen ............................................................ 5-33
SYSTem:COMMunicate:GPIB:TALK.............................................................. 5-34
SYSTem:COMMunicate:SERial:BAUD........................................................... 5-34
SYSTem:COMMunicate:SERial:BITS ............................................................. 5-34
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Boonton 4240 Series RF Power Meter
SYSTem:COMMunicate:SERial:PARity .......................................................... 5-34
SYSTem:COMMunicate:SERial:SBITs............................................................ 5-34
SYSTem:ERRor[:NEXT]? ................................................................................ 5-35
SYSTem:ERRor:CODE?................................................................................... 5-35
SYSTem:ERRor:COUNt? ................................................................................. 5-35
SYSTem:PRESet ............................................................................................... 5-35
SYSTem:VERSion?........................................................................................... 5-35
5.5.14 INSTrument:VERSion Commands............................................................ 5-36
INSTrument:VERSion:FIRMware? .................................................................. 5-36
INSTrument:VERSion:FPGA?.......................................................................... 5-36
5.5.15 SCPI Command Summary......................................................................... 5-37
5.5.16 4230 Emulation GPIB Commands............................................................. 5-42
5.5.17 HP 437B Emulation GPIB Commands...................................................... 5-44
5.5.18 HP 438A Emulation GPIB Commands ..................................................... 5-47
6.
Application Notes ................................................................................................... 6-1
6.1 Pulse Measurements ............................................................................................. 6-1
6.1.1 Measurements Fundamentals......................................................................... 6-1
6.1.2 Diode Detection ............................................................................................. 6-3
6.1.3 4240 Series Features ...................................................................................... 6-4
6.2 Measurement Accuracy ........................................................................................ 6-5
6.2.1 Uncertainty Contributions.............................................................................. 6-5
6.2.2 Discussion of Uncertainty Terms................................................................... 6-6
6.2.3 Sample Uncertainty Calculations................................................................... 6-9
7.
Maintenance ........................................................................................................... 7-1
7.1 Safety .................................................................................................................... 7-1
7.2 Cleaning ................................................................................................................ 7-1
7.3 Inspection.............................................................................................................. 7-1
7.4 Firmware Upgrade ................................................................................................ 7-1
7.5 Firmware Upgrade Instructions ............................................................................ 7-2
8.
Appendix A SCPI Error Messages....................................................................... 8-1
8.1 SCPI Error Messages ............................................................................................ 8-1
9.
Appendix B Warranty & Repair .......................................................................... 9-1
Repair Policy................................................................................................................ 9-1
Limited Warranty......................................................................................................... 9-1
Contents
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Boonton 4240 Series RF Power Meter
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Contents
Boonton 4240 Series RF Power Meter
1. General Information
This instruction manual provides you with the information you need to install, operate and maintain the
Boonton 4240 Series RF Power Meter. Section 1 is an introduction to the manual and the instrument.
Throughout this manual, the designation “4240” will be used to mean the 4240 Series RF Power Meter,
which includes both the single-channel Model 4241 and the dual-channel Model 4242.
1.1 Organization
The manual is organized into seven sections and three Appendices, as follows:
Section 1 - General Information presents summary descriptions of the instrument and its principal
features, accessories and options. Also included are specifications for the instrument.
Section 2 - Installation provides instructions for unpacking the instrument, setting it up for operation,
connecting power and signal cables, and initial power-up.
Section 3 - Getting Started describes the controls and indicators and the initialization of operating
parameters. Several practice exercises are provided to familiarize you with essential setup and control
procedures.
Section 4 - Operation describes the display menus and procedures for operating the instrument locally
from the front panel.
Section 5 - Remote Operation explains the command set and procedures for operating the instrument
remotely over GPIB bus.
Section 6 - Application Notes describes automatic measurement procedures and presents an analysis of
measurement accuracy. Definitions are provided for key terms used in this manual and on the screen
displays.
Section 7 - Maintenance includes procedures for installing software and verifying fault-free operation.
Section 8 - Appendix A - Error Messages defines the messages that are displayed when errors occur.
Section 9 - Appendix B - Warranty and Repair Policy states the policies governing the return and
replacement of modules and instruments during and after the warranty period.
General Information
1-1
Boonton 4240 Series RF Power Meter
1.2 Description
The Model 4240 is a digital signal processor based, single or dual channel, solid state RF power meter. It is
capable of measuring RF power levels from -70 dBm to +44 dBm. The frequency range and power level
are sensor dependent. Boonton 51000 series sensors provide measurement capabilities for frequencies from
10 kHz to 100 GHz. The 4240 is available as the single-channel Model 4241 or the dual-channel Model
4242.
1.3 Features
•
Software. A 32-bit Digital Signal Processor running control software provides display, I/O and
system memory functions for the instrument. Software updates are easily made using either the
GPIB or RS232 interfaces.
•
Alphanumeric Display. The alphanumeric LCD provides clear, unambiguous readouts of the
instrument's setup and measurement values. Simultaneous display of both channels is available in
dual channel mode. A bar graph provides a display of the channel's measured value for nulling
and peaking applications.
Figure 1-1. 4240 Series RF Power Meter
1-2
General Information
Boonton 4240 Series RF Power Meter
•
Dual Independent Channels. When equipped with the optional second measurement channel, the
instrument can display two CW signals simultaneously. Each channel is calibrated and all channel
parameters are channel-independent.
•
Selectable Ranging. Any of seven measurement ranges, or autoranging, can be selected during
instrument setup. The selection will be held until it is changed, or until the instrument is turned
off. When measuring signals with levels that fall within a narrow range, selecting one specific
instrument range may reduce measurement time. Autoranging is useful if the RF signal level is
unknown, or if RF signals with widely varying levels are to be measured.
•
Selectable Filtering. Measurement speed and display stability can be optimized through the use of
selectable filtering. Filter times can be adjusted up to 20 seconds maximum in 50 millisecond
increments.
•
Zeroing. Automatic zeroing (nulling of offsets for the sensor and input channel) is done
independently on each range to eliminate zero carryovers.
•
Power Sensors. A wide range of diode and thermocouple power sensors for both coaxial and
waveguide applications are available for use with the Model 4240. Frequency Calibration factors
traceable to NIST standards are stored in each power sensor’s EEPROM and downloaded to the
instrument. Data sensor adapters are supplied with the Model 4240, however, the power sensor
must be ordered separately.
Diode sensors measure the voltage across a precision resistor, using specially selected diodes.
Detection is square law (true RMS) over approximately the lower two-thirds of the sensor's
dynamic range, and peak detecting over the upper portion. Because the instrument is calibrated
for sine waves over the entire range, measurements at the top one-third of the sensor's dynamic
range are valid only for non-modulated signals. In the RMS region, linearity is excellent, and any
signal type can be measured. The diode range has been extended into the peak detecting region
with the use of real time shaping for the diode curve. When coupled with the high sensitivity of
the diode, such shaping allows a dynamic range of 90 dB. Diode sensors are rugged and have an
overload headroom of more than 5 dB for continuous signals. The dynamic range in the RMS
region can be extended further through use of an external attenuator.
Thermal sensors measure the voltage developed across a dissimilar metal junction caused by the
thermal gradient generated by the RF power being measured. Because these sensors are heat
detecting, they provide true RMS response over their entire range. Very high peak powers (15 to
30 watts) can be accommodated for very short duty cycles and still provide valid results. The
dynamic range is 50 dB. Thermal sensors are not as sensitive as diode sensors.
The data sensor adapter contains non-volatile memory for storage of the calibration data. In
addition, calibration data for up to four sensors can be stored in the instrument's non-volatile
memory. The user can enter both the linearity and high frequency sensor calibration correction
data which are supplied with each sensor. For sensors ordered with the Model 4240, the
calibration data is loaded into the data sensor adapter prior to shipment. When the frequency of
the RF signal to be measured by one of these sensors is entered, the instrument looks up the
appropriate calibration factors, interpolates as necessary, and automatically applies the correction
to the measured value. Calibration factors for sensors ordered with the instrument are stored in the
plastic pouch attached to the inside of the instrument's top cover.
•
Built-In Precision Calibrator. A 50 MHz step calibrator, traceable to NIST, enhances
measurement accuracy and reliability. The user-selectable automatic calibration routine calibrates
most sensors and the instrument in steps over the full dynamic range.
General Information
1-3
Boonton 4240 Series RF Power Meter
•
Simple Instrument Setup and Operation. In the operating mode the functions: Averaging Time,
and Frequency menus are selected with a single keystroke. Values for these parameters are
displayed and can be adjusted by using the arrow and enter keys. Additional operating parameters
can be modified through the menu driven structure accessible via the <Menu> and <Sensor> keys
•
One key press operations. To provide for ease of use operation of the instrument functions that
are used often are performed with a single push of a button. Common operations such as Zeroing
the channel, performing a 0 dBm calibration and setting a Reference Level can be done simply by
pressing the Zero/Cal and REF Level key respectively.
Zero/Cal – When measuring low level signals it is important to zero the channel prior to
measuring the signal. When the Active Channel is measuring levels below approximately -50
dBm, depressing the “Zero/Cal” key will use the measured reading as the zero offset. This allows
for fast zeroing of the channel so that the needed measurement can be performed faster.
The user may also perform a 0 dBm calibration by one key stroke of the “Zero/Cal” button.
Simply connect the sensor to a 0 dBm source and press the “Zero/Cal” key. The instrument detects
that a 0 dBm signal is present and sets a calibration factor accordingly to indicate 0.00 dBm.
The Zero/Cal sub-menu can be displayed by first pressing the Menu key followed by the Zero/Cal
key. From there the user chooses the function (Zero, Fixed Cal, Auto Cal) and the channel to
perform the calibration on.
REF Level – Often relative measurements are required especially when measuring system gains
and losses. One key press of the Ref/Level key makes this job easier and faster to perform. Simply
connect the active channel’s sensor to the input signal of the system under test. Press the
Ref/Level key and the reference level is set! Next connect the sensor to the system output and read
the gain or loss directly from the reference level measurement.
The REF Level sub-menu can be displayed by first pressing the Menu key followed by the REF
Level key. From there the user may LOAD or SET the reference level on either channel.
•
Chart Recorder Output. A 0 to 10 volt dc output, proportional to the measurement values, is
available for application to a chart recorder. The Recoreder Output is selectable to track either
channel 1, channel 2 or the active channel.
•
Flexible Remote Control. All instrument functions except power on/off can be controlled
remotely via the standard GPIB bus interface or RS232 connection. Setup of interface parameters
is menu driven; front panel indicators keep the user informed of bus activity. Remote control
programming is performed using industry-standard SCPI programming syntax. The 4230
emulation mode is provided for users that prefer back compatibility with legacy Boonton products
such as the 4230 series and 4220 line of power meters.
•
Stored Configurations. For applications in which the same instrument configurations are used
repeatedly, up to 10 complete setups can be stored and recalled.
1-4
General Information
Boonton 4240 Series RF Power Meter
1.4 Accessories
Optional 4240 accessories that can be ordered from Boonton Electronics. A data sensor adapter for each
channel installed along with the AC power cord is supplied with the instrument. One or more Boonton
51000 series power sensors are required. The power sensors are not supplied as part of the instrument, but
must be ordered separately. Additional available accessories include the following:
a. Model 95004701A F/F Adapter, 41-2A (for connecting Model 41-2A cables end to end)
b. Model 95004901A Bulkhead Connector F/F, 41-2A (for connecting Model 41-2A cables end
to end)
c. Model 95401501A Rack Mounting Kit
d. Model 95109001A Additional Sensor Data Adapters
Table 1-1
Accessories for the 4240 Series
Selection
Part Number
Description
56810400A
98601300x*
Line Cord (US)
Manual CD, Boonton Measurement Instruments (CD-ROM)
(x* - denotes revision level)
545504000
95401501A
95403001A
95403003A
95105501A
95109101A
95109102A
95109001A
41-2A
41-2A/10
41-2A/20
41-2A/50
41-2A/100
95004701A
95004901A
Fuse, 0.5A 250V
Rack Mounting Kit
Rack Mounting Kit (Brackets only)
Rack Mounting Kit (Brackets with handles)
Type N to K Adaptor (for sensors with K-Connector®)
CW Sensor Combo Cable/Data Adapter – 5 ft (1.27 m)
CW Sensor Combo Cable/Data Adapter – 10 ft (2.54 m)
CW Sensor Data Adapter – with connector for 41-2A cable
CW Sensor Cable – 5ft (1.27 m)
CW Sensor Cable – 10ft (2.54 m)
CW Sensor Cable – 20ft (5.05 m)
CW Sensor Cable – 50ft (12.7 m)
CW Sensor Cable – 100ft (25.4 m)
F/F Adapter, 41-2A (for connecting Model 41-2A cables end to end)
Bulkhead Connector F/F, 41-2A (for connecting Model 41-2A cables
end to end)
Instruction Manual 4240 Series, English (Printed w/binder)
Standard
Optional
98406700A
Sensors
For sensor selection, refer to the BOONTON Sensor Manual (985019).
1.5 Models, Options and Configurations
Model 4241. One measurement channel; sensor and calibrator connectors located on the front panel.
Model 4242. Two measurement channels; sensor and calibrator connectors located on the front panel.
Opt -01. Rear Panel Channel input(s).
Opt -02. Rear Panel Calibrator output.
Opt -30. Warranty option: Extend factory warranty to 3 years
General Information
1-5
Boonton 4240 Series RF Power Meter
Option designations are appended to the instrument’s base model number. For example, Model 4242-0102 would be a two-channel instrument with sensor and calibrator connectors all on the rear panel.
Specials. Custom configurations have –S/n appended to the model number, where n is a unique number.
1.6 Specifications
Performance specifications for the 4240 Series are listed in Table 1-2.
Performance specifications for all Boonton power sensors are found in the Boonton Sensor Manual, which
may be ordered as Boonton p/n 98501900x* (x* - denotes revision level).
Table 1-2 4240 Series Performance Specifications
(Specifications are subject to change without notice)
SENSOR INPUTS
RF Frequency Range:
Power Range:
Power Sensors:
Dynamic Range:
1 MHz to 110 GHz1
1
-70 to +44 dBm
Accepts sensor data adapter and is compatible with all Boonton
diode and thermal sensors
Up to 90 dB with diode sensors; up to 50 dB with thermal sensors
( 1 Sensor dependant )
FEATURES
Display
Display Units
Display Resolution
Display Offset
Limiting
Peak Power Mode
Ranging
Filtering
Zeroing
High Frequency Cal Factors:
Reference Level
1-6
Menu-driven 20 character x 4 line LCD
MW, kW, W, mW, µW, nW, dBW, dBm, dBuW, dBnW, dBr, %
0.001 dB or 5 digits (in Watts mode)
-99.99 dB to +99.99 dB in 0.01 dB steps
Individual high and low limit thresholds, -99.99 dB to +99.99 dB
Programmable duty cycle from 0.01 to 100.00% in 0.01 steps
Manual (7 ranges) or autoranging
Filter times to 20.00 seconds in 0.05 second increments
Automatic function; calculates, stores, and applies zero corrections to
each range
+3 dB to -3 dB in 0.01 dB steps; cal factors also stored in sensor
data adapter.
-99.99 dB to +99.99 dB in 0.01 dB steps for dBr measurements
may be express in % in linear mode.
General Information
Boonton 4240 Series RF Power Meter
Table 1-2
4240 Series Performance Specifications (continued)
(Specifications are subject to change without notice)
UNCERTAINTIES
Measurement Accuracy
Instrument Uncertainty
Noise/signal Percentage
Power Reference Uncertainty
Sensor Shaping
Temperature Drift
Sum of following uncertainties (errors are + worst case): instrument
uncertainty, noise/signal percentage, power reference uncertainty,
sensor shaping, temperature drift, mismatch, and frequency
calibration factors
+0.23% (+0.01 dB) at full scale; +0.46% (+0.02 dB) at 1/10 full scale
Convert 2 sigma noise listed in the Power Sensor Manual, to percent
of the applied power level.
Refer to Table 1-2 Power Reference: Level Accuracy
+1.0% (+0.04 dB) typical, Power Sensor Manual
Refer to Power Sensor Manual
MEASUREMENT SYSTEM
Sensor inputs:
Measurement Technique:
One or two sensor measurement channels.
24 bit Sigma-delta A/D converter per channel.
CALIBRATION SOURCE
Internal Calibrator
Operating Modes:
Off, On CW
Frequency:
50.025 MHz ± 0.1%
Level Range:
-60 to +20 dBm
Resolution:
0.1 dB
RF Connector:
Type N
Source VSWR:
1.05 (reflection coefficient = 0.024)
Accuracy, 0C to 20C, NIST traceable:
At 0 dBm: ±0.055 dB (1.27%)
+20 to -39 dBm: ±0.075 dB (1.74%)
-40 to -60 dBm: ±0.105 dB (2.45%)
Auto-calibration:
The Calibrator is used to automatically generate linearity calibration
data for CW power sensors. Can be used to provide test signals.
General Information
1-7
Boonton 4240 Series RF Power Meter
Table 1-2
4240 Series Performance Specifications (continued)
(Specifications are subject to change without notice)
EXTERNAL INTERFACES
Remote Control:
GPIB:
RS232:
Complies with IEEE-488.1 and SCPI version 1993.
Implements AH1, SH1, T6, LE0, SR1, RL1, PP0, DC1, DT1, C0, and E1.
Type-D connector, 9 pins.
Inputs:
Front or Rear panel sensor connector; rear panel IEEE-488 connector
and RS-232 connector.
Outputs
Front panel or optional Rear panel CAL OUT connector, 50 MHz, 100
mW max; rear panel recorder BNC connector, 9.09 kilohm impedance, 0
to 10 volts into 1 megohm (may be operated into 1 kilohm for 1V fs).
PHYSICAL AND ENVIRONMENTAL CHARACTERISTICS
Case Dimensions:
8.26W x 3.48H x 13.5D inches (21.0 x 8.9 x 34.3 cm), Half-rack width, 2U
height
Weight:
5 lbs (2.3kg)
Power Requirements:
90 to 264 VAC, 47 to 63 Hz, (25VA) maximum.
Operating Temperature2: 0 to 55 °C
Storage Temperature2:
-30 to +60 °C
Humidity2:
95% maximum, non-condensing
Altitude2:
Operation up to 15,000 feet
Shock2:
Withstands ±30G, in X, Y, and Z axes
Vibration2:
Withstands 2G
( 2 as per MIL-PRF-28800F )
1-8
General Information
Boonton 4240 Series RF Power Meter
Table 1-2
4240 Series Performance Specifications (continued)
(Specifications are subject to change without notice)
OTHER CHARACTERISTICS
Display:
Dot matrix 80 character LCD module (4 lines by 20 characters)
Keyboard:
11 Key conductive rubber
Processor:
32-bit Digital Signal Processor
Panel setup storage:
Can save and recall 10 complete “user” setups.
REGULATORY CHARACTERISTICS
CE Mark:
Full compliance with the following European Union directives and standards:
Safety: Low Voltage Directive 2006/95/EC
IEC 61010 – 1 : 2001 (2nd Edition); EN 61010 – 1 : 2001 (2nd Edition)
EMC:
Electromagnetic Compatibility Directive 2004/108/EC
IEC 61000-3-2: 2000
Limits for harmonic current emissions
IEC 61000-3-3: 2002
Limitation of voltage changes, voltage
fluctuations and flicker
IEC 61000-4-2: 2001
Electrostatic discharge immunity test
IEC 61000-4-3: 2002
Radiated, radio-frequency, electromagnetic
field immunity test
IEC 61000-4-4: 2004
Electrical fast transient/burst immunity test
IEC 61000-4-5: 2001
Surge immunity test
IEC 61000-4-6: 2003
Immunity to conducted disturbances,
induced by radio frequency fields.
IEC 61000-4-11: 2004
Voltage dips, short interruptions and voltage
variations immunity test
EN 61326-1: 2006
Electrical equipment for measurement,
control and laboratory use – EMC
requirements - Part 1: General requirements
RoHS: RoHS Directive 2002/95/EC
Construction:
Manufactured to the intent of MIL-T28800E, Type III, Class 5, Style E
General Information
1-9
Boonton 4240 Series RF Power Meter
This page intentionally left blank.
1-10
General Information
Boonton 4240 Series RF Power Meter
2. Installation
This section contains unpacking and repacking instructions, power requirements, connection descriptions and preliminary
checkout procedures.
2.1 Unpacking & Repacking
The 4240 Series is shipped complete and is ready to use upon receipt. Figure 2-1 shows you the various pieces included in
the packaging and the order in which they are loaded into the container. Actual details may vary from the illustration.
Note
Save the packing material and container to ship the instrument, if necessary. If the original materials (or
suitable substitute) are not available, contact Boonton Electronics to purchase replacements. Store materials
in a dry environment. Refer to the Physical and Environmental Specifications in Table 1-2 for further
information.
Figure 2-1. Packaging Diagram
Installation
2-1
Boonton 4240 Series RF Power Meter
Table 2-1 4240 Series Packing List
INSTRUMENT (See also Table 1-1)
4240 Series RF Power Meter
Line Cord
Boonton Instruction Manual CD
SENSOR(S) (packaged separately)
Sensor(s)
Sensor Cable(s)
Type N to SMA Adapter (if required)
BOONTON Sensor Manual CD
For bench-top use, choose a clear, uncluttered area. Ensure that there is at least 2" of clearance at the exhaust vents on the
side panels. Pull-down feet are located on the bottom of the instrument. Rack mounting instructions are provided with the
optional rack mount kit.
2.2 Power Requirements
The 4240 Series is equipped with a switching power supply that provides automatic operation from a 90 to 260 volt, 47 to 63
Hz, single-phase, AC power source. Maximum power consumption is 15W and 25VA. For metric fuse sizes, use the metric
fuse kit supplied. Connect the power cord supplied with the instrument to the power receptacle on the rear panel. See Figure
3-2.
Caution
Before connecting the instrument to the power source, make certain that a 0.5-ampere time delay fuse (type
T) is installed in the fuse holder on the rear panel.
Before removing the instrument cover for any reason, position the input module power switch to off (0 =
OFF; 1 = ON) and disconnect the power cord.
2.3 Connections
Sensor(s)
Connect the sensor that covers the frequency range of the measurement to the CHANNEL 1 sensor
connector on the front (Standard) or rear (Optional) panel, as follows. Connect the sensor to the sensor
cable. Connect the sensor cable to the CHANNEL 1 Input, holding the red mark on the cable connector up.
For two-channel measurements, use the same procedures to connect the second sensor to the CHANNEL 2
Input.
Note
If the sensor connector is not a type N, install the appropriate adapter (from the accessories kit) on the
calibrator output connector.
2-2
Installation
Boonton 4240 Series RF Power Meter
Recorder
If a recorder is to be used to record measurement data, connect the recorder to the recorder BEC connector
on the rear panel. Output impedance is 9.06 kilohms, and the output voltage range is 0 to 10 volts dc.
Remote
If the instrument is to be operated remotely using the GPIB (IEEE-488) bus, connect the instrument to the
bus using the rear panel GPIB connector and appropriate cable. For RS-232 control, the rear panel 9 pin
RS-232 connector should be used. In most cases, it will be necessary to configure the interface used via
the Menu > SETUP > IEEE or Menu > SETUP > RS232 menus.
2.4 Preliminary Check
The following preliminary check verifies that the instrument is operational and has the correct software installed. It should
be performed before the instrument is placed into service. To perform the preliminary check, proceed as follows:
1.
Connect the AC (mains) power cord to a suitable AC power source; 90 to 264 volts AC, 47 to 63 Hz, with a
capacity in excess of 75 W. The power supply will automatically adjust to voltages within this range.
2.
Attach the sensor data adapter(s) to the front panel CHANNEL connector(s).
3. Set the POWER switch to the ON (1) position.
4.
Verify that "BOONTON ELECTRONICS, 4242 RF Power Meter, REV XXXXXXXX" is momentarily
displayed where XXXXXXXX represents the revision code. (Note: Model number 4241 display for single
channel instruments.) While the sign-on screen is displayed the phrase “ A WIRELESS TELECOM GROUP
COMPANY” is scrolled along the second line.
Figure 2-2. Typical Power-On Display
5.
Verify that the measurement display showing "CH 1" only for Model 4241 or "CH 1" and "CH 2" for Model
4242. Other data on the display will depend upon previous settings.
Installation
2-3
Boonton 4240 Series RF Power Meter
6.
Press the <MENU> key and select DIAGNOSTICS with the down arrow key. Press <ENTER>.
Verify the following sub-menu:
RTN
SELFTEST
SWITCHES
RECORDER
7.
<
Press <Enter> to execute the self-test. The items tested are as follows:
PROCESSOR
SRAM MEMORY
EEPROM
Each test will display the OK message if passed. When the test is completed the menu will reappear.
8.
Use the <Down Arrow> key to move the "<" cursor to SWITCHES and press <ENTER>. Press each
front panel key, avoiding <MENU> until last. Each key press will result in an identifying message;
<MENU> will exit the test and return to the MENU.
9.
Use the <Down Arrow> key to select RECORDER and press <ENTER>. This test will sequentially
send a DC voltage in 1 volt steps to the recorder output BNC connector on the rear panel. The test
will continue until <MENU> is pressed. Use a DC voltmeter to verify correct operation.
10. Press <MENU> to return to the measurement display.
11. Press the <Sensor> key and verify that the RF Sensor serial number(s) appear under the channel
heading(s). An active channel with no sensor installed will report a table number.
12. Press the <AVG> key and verify that the filter time and number of samples appear for each active
channel.
13. With each installed sensor connected to the CAL OUT, press the <Menu> key followed by the
<Zero/Cal> key and select ZERO function for the active channel. Verify the ZERO operation
completes successfully.
14. Next press the <Menu> key followed by the <Zero/Cal> key and select the FIXED CAL function for
the active channel. Verify the CALIBRATE operation completes successfully.
15. Repeat steps 13 and 14 for channel 2 if installed.
16. Connect a GPIB controller to the Model 4240. Verify that the instrument can be addressed to Listen at
its IEEE bus address, and set to Remote. The display must show the correct status on the bottom line
of the display. For message passing, the line terminators for the controller and the Model 4240 must
be compatible for both Listen and Talk. Use <Menu> <SETUP> <IEEE> to set address and
terminators for the 4240. Address the Model 4240 to Listen/Remote and send the command "*IDN?"
EOL. Then address the Model 4240 to Talk (controller to listen) and verify that the correct
identification string is returned. For example using SCPI emulation the ID string returned would be as
follows;
BOONTON ELECTRONICS, 4242, 11002, 20100717
17. Connect a dumb terminal or PC serial terminal to the Model 4240. Use a null modem if the terminal is
wired as DCE. For message communication to take place, the parameters of the serial connection and
message strings must agree between the terminal and the Model 4240. Use <Menu> <SETUP> <RS232> to set parameters for the 4240. Send the command or "*IDN?" EOL and verify that the correct
identification string is returned.
2-4
Installation
Boonton 4240 Series RF Power Meter
3. Getting Started
This chapter will introduce the user to the 4240 Series. The chapter will identify objects on the front and rear panels, identify
display organization, list the initial configuration of the instrument after reset, demonstrate how to calibrate the sensors, and
provide practice exercises for front panel operation. For additional information you should see Chapter 4 "Operation."
3.1 Organization
Subsection 3.2 Operating Controls, Indicators and Connections identifies the control features and connections on the front
and rear panels.
Subsection 3.3 Operation identifies the front panel keys, their functions and the menu structure while describing the various
display modes.
3.2 Operating Controls, Indicators and Connections
Figures 3-1 and 3-2 illustrate the controls, indicators and connectors on the front and rear panels, respectively, of the standard
instrument. Refer to Table 3-1 for a description of each of the illustrated items. Connectors indicated by an asterisk (*) may
be front or rear-mounted, depending on the option selected. The function and operation of all controls, indicators and
connectors are the same on the standard and optional models.
Getting Started
3-1
Boonton 4240 Series RF Power Meter
Figure 3-1. Standard 4240 Series RF Power Meter - Front Panel
Table 3-1 Operating Controls, Indicators and Connections
Reference #
Front Rear Nomenclature
Function
1
1
Internal Calibrator
The output of the built-in 50MHz programmable calibrator is available from a
Type-N connector located on the front, or optionally on the rear panel of the
instrument. This calibrator is used to automatically calibrate sensor offset and
linearity, and can also be used as a general purpose calibration signal source.
2
2
Channel Inputs
One or two Channel inputs are located on the front, or optionally on the rear
panel of the instrument. These are 10-pin precision connectors designed to accept
only Boonton CW power sensors.
Caution
Do not attempt to connect anything other than a
Boonton power sensor and sensor data adapter to the Channel inputs!
The Channel inputs are not measurement terminals and cannot be used
for other than the intended purpose.
3
Display Screen
3-2
LCD readout of the measurements and user interface for editing of the
instrument's operating parameters.
Getting Started
Boonton 4240 Series RF Power Meter
Table 3-1 Operating Controls, Indicators and Connections (continued)
Reference #
Front Rear Nomenclature
Function
4
◄ and ► Keys
In entry mode, pressing ◄advances the cursor to the left. In the measurement
mode of operation pressing the ◄ key sets the Active channel to Linear
measurement units (Watts, %). In entry mode, pressing ►advances the cursor to
the right. In the measurement mode of operation pressing the ►key sets the
Active channel to Log measurement units (dBm, dBr).
5
▲ and ▼ Keys
Used for incrementing or decrementing numeric parameters, selecting from lists,
or scrolling through multi-line displays. In the measurement mode of operation
pressing the ▲ key moves the Active Channel cursor up on the display. For
example if the active channel is set to 2, pressing the ▲key will cause channel 1
to be the active channel. Pressing the ▼ key moves the Active Channel cursor
down on the display. If the active channel is set to 1, pressing the ▼ key will
cause channel 2 to be the active channel.
6
Enter Key
In entry mode, initiates the procedure to change a parameter. In parameter entry
mode, terminates the current command and changes the parameter to the last
displayed value. In the measurement mode, display the active channels
CHANNEL menu.
7
Power Switch
Turns the instrument off and on.
8
<Menu> Key
Displays and allows editing of the instrument's operating parameters. Returns
instrument to local mode when operating in the bus remote mode. Escapes back
to measurement screen from any menu.
9
<Sensor> Key
Displays the serial number of the installed sensors and allows for editing of the
sensor parameters.
10
<FREQ> Key
Selects the operating frequency display.
11
<AVG> Key
Selects the filter averaging display for the measurement value.
12
<Zero/CAL> Key
One Key Press Operation. When measuring low level signals it is important to
zero the channel prior to measuring the signal. When the Active Channel is
measuring levels below approximately -50 dBm, depressing the <Zero/Cal> key
will use the measured reading as the zero offset. This allows for fast zeroing of
the most sensitive range of the channel so that the needed measurement can be
performed faster.
The user may also perform a 0 dBm Fixed Calibration by one key stroke of the
<Zero/Cal> button. Simply connect the sensor to a 0 dBm source and press the
<Zero/Cal> key. The instrument detects that a 0 dBm signal is present and sets a
calibration factor accordingly to indicate 0.00 dBm.
The Zero/Cal menu can be displayed by first pressing the <Menu> key followed
by the <Zero/Cal> key. From there the user chooses the function (Zero, Fixed
Cal, Auto Cal) and the channel to perform the calibration on.
Getting Started
3-3
Boonton 4240 Series RF Power Meter
Table 3-1 Operating Controls, Indicators and Connections (continued)
Reference #
Front Rear Nomenclature
13
<REF Level> Key
Function
Often relative measurements are required especially when measuring system gains
and losses. One key press of the Ref/Level key makes this easier and faster to
perform. Simply connect the active channel’s sensor to the input signal of the
system under test. Press the Ref/Level key and the reference level is set! Next
connect the sensor to the system output and read the gain or loss directly from the
reference level measurement.
The REF Level menu can be displayed by first pressing the <Menu> key followed
by the <REF Level> key. From there the user may LOAD or SET the reference
level on either channel.
14
Recorder
Provides a DC voltage proportional to the measured values for use by an external
recorder.
15
RS232
9-pin D-sub connector for connecting the power meter to the remote control Serial
Bus. Communication parameters can be configured through the <SETUP <RS232>
menu.
16
GPIB
24-pin GPIB (IEEE-488) connector for connecting the power meter to the remote
control General Purpose Instrument Bus. GPIB parameters can be configured
through the <SETUP <IEEE> menu.
17
AC Line Input
A multi-function power input module is used to house the AC line input, main
power switch, and safety fuse. The module accepts a standard AC line cord,
included with the power meter. The power switch is used to shut off main
instrument power. The safety fuse may also be accessed once the line cord is
removed. The instrument’s power supply accepts 90 to 264VAC, so no line voltage
selection switch is necessary.
Caution
3-4
Replace fuse only with specified type and rating:
0.5 A-T (time delay type), 250VAC
Getting Started
Boonton 4240 Series RF Power Meter
Figure 3-2. 4240 Series - Rear Panel
(Shown without optional rear panel connectors not installed)
Getting Started
3-5
Boonton 4240 Series RF Power Meter
3.3 Operation
The Model 4240 can be configured for operation via the six switches on the front panel;
<Menu>
<Sensor>
<FREQ>
<AVG>
<Zero/Cal> 1
1
<REF Level> 1
( single key press operation)
Pressing a key will bring the instrument to the next submenu. A flow chart of the instrument’s command structure is
shown in figure 3-5. The <Menu> key serves as an ESCAPE key to cancel the current operation from any point and return
to the measurement screen.
To change a value , use the arrow keys to position the cursor to the desired parameter. Press the <Enter> key and then use
the up/down arrow keys to scroll through the parameter list. When a number is to be entered, use the left/right arrow keys
to position the cursor under the number that is to be changed, then use the up/down arrow keys to increment/decrement
the number. Holding the up/down arrow key will initiate repeat mode to allow rapid movement through the selection.
Within a submenu, the ∧ ∨ indicators are displayed in the upper right potion of the display when the current screen has
additional information that can be obtained by scrolling with the up/down arrow keys. Three conditions are possible:
1.
2.
3.
∧
Use the up arrow key to scroll the screen upward for additional information.
∨ Use the down arrow key to scroll the screen downward for additional information.
∧ ∨ Use the up/down arrown keys to scoll the screen upward/downward for additional information.
Additonal freatures introduced in the 4240 are the ‘single key press operation’ for the <Zero/Cal> and <REF Level> keys.
See section 3.3.5 and 3.3.6 for further details. Also the arrow keys and the <Enter> key have special functions while
measurements are displayed.
Arrow keys group. Selection of the Active Channel and the channel’s measurement units may be accomplished by use of
the arrow keys while in the measurement mode of operation.
Up Arrow key. Moves the Active Channel cursor up on the display. For example if the active channel is set to 2, pressing
the <Up Arrow> key will cause channel 1 to be the active channel.
Down Arrow key. Moves the Active Channel cursor down on the display. For example if the active channel is set to 1,
pressing the <Down Arrow> key will cause channel 2 to be the active channel.
Left Arrow key. Pressing this key sets the Active Channel to Linear measurement units (Watts, %).
Right Arrow key. Pressing this key sets the Active Channel to Log measurement units (dBm, dBr).
Enter key. When in the measurement mode of operation pressing the <Enter> key causes the instrument to drop down
into the CHANNELS menu using the Active Channel as a pointer to the associated channels menu. This provides faster
settings of channel parameters such as units, resolution, duty cycle, offset, range, alarm setting and limits.
3-6
Getting Started
Boonton 4240 Series RF Power Meter
DUAL CHANNEL
A
A
C
C
M
M
M
M
M
M
M
M
L
±
(
B
A
R
M
M
L
±
(
B
A
R
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)
D
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)
U
U
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P
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∆
U
U
U
P
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∆
U
U
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P
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∆
SINGLE CHANNEL
A
C
M
KEY:
M
M
M
M
L
±
(
B
A
D
D
D
D
D
U
R
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)
D
"="
0 through 9 or a decimal point
L
"="
M
M
M
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U
U
U
U
A
M
C
D
∧,∨
(alarm mode)
"="
CH1, CH2, CH1+2, CH1/2
"="
V, mV, nW, uW, mW, kW, MW,dBm,
dBnW, dBuW, dBnV, dBuV, dBmV, dBV
"="
Active Channel pointer
Figure 3-3. Measurement Display, Local Mode
A
A
C
C
M
M
M
M
M
M
R
E
M
KEY:
M
M
L
±
D
(
B
A
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L
±
D
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)
D
D
D
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D
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T
L
K
REM
"="
Remote mode enabled
LSN
"="
Listener addressed
TLK
"="
Talker addressed
SRQ
"="
Service Request activated
U
U
U
P
K
∆
U
U
U
P
K
∆
S
R
Q
Figure 3-4. Measurement Display, Remote Mode
Getting Started
3-7
Boonton 4240 Series RF Power Meter
Figure 3-5. Model 4240, Command Set
Last Menu Operation. In keeping with minimum key stokes to perform a function repeatedly, the control program can
remember the last menu the user was at prior to returning to the measurement display. In doing this submenu functions can be
quickly selected and parameters changed getting the user back to the measurement display faster.
For example, suppose the user wants to check the sensors linearity using the internal calibrator. The output level needs to be
changed repeatedly recording the measurement results at each level. First, the CALIBRATOR LEVEL function is selected.
This is accomplished by the following key presses (assuming the Calibrator Signal is already On); <Menu> – <Down Arrow>
(to point to CALIBRATOR) – <Enter> –Next press <Enter> to enable the setting of the desired level then press <Enter> to set
the calibrator to that level.
Now pressing the <Menu> key will return the instrument to the measurement display. To change the level simply pressing the
<Menu> key returns the instrument to the CALIBRATOR LEVEL function.
In this example two key strokes are eliminated which may not seem like a lot but if many levels are needed to be tested,
remembering the last menu will save a lot time.
Once in a submenu, the previous menu can always be reached by depressing the <Up Arrow> until RTN or escape to the
parent menu using the <Left Arrow> key. If the user exits out to the measurement screen by this method, pressing the <Menu>
key will bring up the top level menu.
3-8
Getting Started
Boonton 4240 Series RF Power Meter
3.3.1 Menu Key.
The instrument's, CHANNELS, CALIBRATOR, SETUP, REPORT and DIAGNOSTIC functions are accessed when the
<Menu> key is pressed. Using the up/down arrow keys, the cursor can be positioned to select from the five submenus.
Channel Menu. An example of the display for the Channels menu is shown in Figure 3-7. Although the figure shows eleven
lines, the instrument can only display four at a time. Therefore, it will be necessary to use the up/down arrow keys to sequence
through the commands. When viewing the commands, the instrument will retain the first line as a header and use the next
three lines to scroll through the remaining commands.
Table 3-2 gives a description of the commands available from the Channels menu. The associated parameters, and factory
default settings are also given.
Calibrator Menu. An example of the display for the Calibrator menu is shown in Figure 3-8. Table 3-3 gives a description of
the commands, parametes and default settings of the Calibrator menu.
Setup Menu. An example of the display for the Setup menu is shown in Figure 3-9. It will be necessary to use the up/down
arrow keys to sequence through the commands since there are more than four lines of information to be displayed. When
sequencing through the commands, the instrument will retain the first line as a header and use the next three lines to scroll
through the command list.
R
T
N
C
H
A
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N
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L
S
C
A
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S
T
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S
Figure 3-6. Main Menu Display
R
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9
0
9
Figure 3-7. Channels Menu Display
Getting Started
3-9
Boonton 4240 Series RF Power Meter
Table 3-2 CHANNEL MENU Functions
Function
Description
Parameters
RTN
Returns the instrument to the
previous menu.
n/a
UNITS
Units used for measurement
display.
dBm, WATTS
dBm
RES
Display resolution
X.X, X.XX, X.XXX dBm or/
XXX, XXXX, XXXXX Watts
X.XX
DUTY
Duty cycle for pulse power
applications; a value less than
100.00 enables pulse power
mode.
0.01 to 100.00%
100.00
BAR
Enables the bar graph on the
measurement display.
ON, OFF
ON
MODE
Sets the display mode for
channel 2; only available when
two channels are installed. The
units for sum and ratio modes
track the units selected for
channel 2.
CH2,CH1+2, CH1/2
OFF
CH2
OFFSET
Sets the offset added to the
measured value.
-99.99 to 99.99 dB
0.00
RANGE
Selects and hols the instrument’s
measurement range. If
repetitive measurements are to
be made over a narrow range of
levels, selecting the appropriate
instrument range may speed
measurements.
AUTO, 0,1,2,3,4,5,6
AUTO
ALARM
Enables alarm mode; the ∨ or
∧ symbol is displayed before
the channel mode designator on
the measurement display to
indicate when the upper or
lower threshold limit is
Exceeded.
ON, OFF
OFF
HI LIMIT
Upper threshold limit for the
alarm function.
-99.99 to 99.99
99.99
LO LIMIT
Lower threshold limit for the
alarm function.
-99.99 to 99.99
-99.99
3-10
Getting Started
Defaults
Boonton 4240 Series RF Power Meter
R
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-
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O
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.
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Figure 3-8. Calibrator Menu Display
Table 3-3 CALIBRATOR MENU Functions
Function
Description
Parameters
RTN
Returns the instrument to the
previous menu.
n/a
LEVEL
The calibrator output level in
dBm.
-60.0 to +20.0
-60.0
SIGNAL
Sets the calibrator output on
or off.
ON, OFF
OFF
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Defaults
1
2
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Figure 3-9. Setup Menu Display
Table 3-4 SETUP MENU Functions
Function
Description
Parameters
RTN
Returns the instrument to the
previous menu.
n/a
RECALL
Recalls one of ten user
defined instrument
configurations or the factory
setup.
DEFAULT, 1-10,
SANITIZE 1
1
Defaults
DEFAULT
SANITIZE initializes all program locations to DEFAULT settings
Getting Started
3-11
Boonton 4240 Series RF Power Meter
Table 3-4 SETUP MENU Functions (continued)
Function
Description
Parameters
Defaults
SAVE
Saves the current instrument
configuration to one of ten
non-volatile memory
locations.
1-10
1
POWER-UP
Instructs the instrument to power-up DEFAULT, 1-10
to the specified configuration.
DEFAULT
KEY BEEP
Turns on/off the key beep.
ON, OFF
OFF
IEEE
Brings the instrument to the
IEEE menu.
see table 3-5
n/a
RS232
Brings the instrument to the
RS-232 menu.
see table 3-6
n/a
LINEFREQ
Select line (mains) frequency.
50Hz, 60Hz
n/a
INSTR CAL
Refer to Service Manual.
n/a
n/a
IEEE Menu. The IEEE submenu is used to configure the Model 4240 for communications over the GPIB. An example of the
menu is shown in Figure 3-10 and the description of the commands, parameters and factory defaults is given in Table 3-5.
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Figure 3-10. IEEE Menu Display
Table 3-5 IEEE MENU Functions
Function
Description
Parameters
RTN
Returns the instrument to the
previous menu.
n/a
ADDRESS
GPIB address assigned to the
instrument.
0 to 30
n/a
EMULATION
GPIB emulation mode.
SCPI, 437B, 438A, 4230
SCPI
3-12
Getting Started
Defaults
Boonton 4240 Series RF Power Meter
Table 3-5 IEEE MENU Functions (continued)
Function
Description
Parameters
Defaults
EOS LSTN
End of string indicator for
received messages.
LF, CR, CRLF, NONE
Where:
LF = Line Feed
CR = Carriage Return
CRLF = Carriage Return
and Line Feed
LF
EOS TALKER
End of string character sent
with transmitted messages.
LF, CR, CRLF, NONE
LF
EOI
Enables/disables the end or
identify hardware control line.
ON, OFF
OFF
SRQ MASK
Service request interrupt mask.
See Table 4-7 for bit
descriptions.
0 to 255
Where:
255 enables all interrupts
0
RS232 Menu. The RS232 menu is used to configure the Model 4240 for serial communications over the RS-232 bus. An
example of the submenu is shown in Figure 3-11 and an explanation of the commands, parameters and factory defaults is
given in Table 3-6.
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8
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N
O
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F
C
R
L
F
0
0
Figure 3-11. RS232 Menu Display
Table 3-6 RS232 MENU Functions
Function
Description
Parameters
RTN
Returns the instrument to the
previous menu.
n/a
BAUD RATE
Rate at which data is
transferred over the bus.
300, 600, 1200, 2400, 4800,
9600, 19200, 38400, 57600,
115200
38400
DATA BITS
Number of data bits in a message.
7, 8
8
STOP BITS
Number of stop bits in a message.
1, 2
1
Getting Started
Defaults
3-13
Boonton 4240 Series RF Power Meter
Table 3-6 RS232 MENU Functions (continued)
Function
Description
Parameters
Defaults
PARITY
Parity bit mode in a message.
ODD, EVEN, NONE
NONE
EOS LSTN
End of string indicator for
received messages.
LF, CR, CRLF, NONE
Where:
LF = Line Feed
CR = Carriage Return
CRLF = Carriage Return
and Line Feed
LF
EOS TALKER
End of string character sent
with transmitted messages.
LF, CR, CRLF, NONE
CRLF
SRQ MASK
Service request interrupt mask.
See Section 5.5.1 *STB? for bit
descriptions.
0 to 255
Where:
255 enables all interrupts
0
REPORT Display. The REPORT menu item displays the versions of the firmware and FPGA image installed in the
instrument. The SCPI specification compliance version is also displayed in this report. This display is for informational
purposes only and does not support any editing of the data. The REPORT display is shown in Figure 3-12.
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1
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8
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9
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1
1
Figure 3-12. Report Display
Diagnostics Menu. The Model 4240 can be directed to perform self-tests from the diagnostics menu. The Diagnostics menu is
shown in Figure 3-13 and a description of each command is given in Table 3-7.
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Figure 3-13. Diagnostics Display
Table 3-7 DIAGNOSTICS MENU Functions
Function
Description
Parameters
Defaults
RTN
Returns the instrument to the
previous menu.
n/a
n/a
3-14
Getting Started
Boonton 4240 Series RF Power Meter
Table 3-7 DIAGNOSTICS MENU Functions (continued)
Function
Description
Parameters
Defaults
SELF TEST
Instructs the instrument to
perform internal diagnostics
and the display test.
n/a
n/a
SWITCHES
Interactive test to verify proper
operation of the front panel
switches.
n/a
n/a
RECORDER
The recorder output DAC is
exercised through its full range
from 0 to 10 V.D.C. in 1V steps
continuously until the <Menu>
key is depressed.
n/a
n/a
3.3.2 Sensor Key.
Pressing the <Sensor> key brings the instrument to the Sensor menu and facilitates viewing and editing of the power sensor's
parameters. An access code is required to enter the editing mode (refer to Figure 3-15). A sample display of the Sensor menu
is shown in Figure 3-14.
The instrument is capable of using sensor calibration data from either the sensor data adapters or from any one of four internal
tables. The sensor calibration data contained within the sensor data adapter is only accessible to the installed channel. For
example, Channel 1 can use the sensor calibration data from any of the internal tables or the sensor data adapter 1. Similarly,
Channel 2 can use the sensor calibration data from any of the internal tables or the sensor data adapter 2.
Referring to Figure 3-14, the cursor can be positioned to three fields. The two fields below the 'CH1' and 'CH2' indicate the
serial number of the sensor whose calibration data is selected for channels 1 and 2 respectively. The instrument uses this data
for the linearity and high frequency correction data and automatically applies the correction to the measured value.
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3
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9
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7
2
Figure 3-14. Sensor Display Menu
To change the current selection for channel 1, use the arrow keys to move to the SER# command line and position the cursor
below the 'CH1' field. Press the <Enter> key and use the up/down arrow keys to scroll through the parameter list. The
parameter list typically consists of serial numbers for each power sensor. Scroll through the list until the desired serial number
is displayed and press <Enter> to accept. Move the cursor below the 'CH2' field and follow the same procedure used to change
the table for channel 2.
The instrument detects the presence of the sensor data adapter and automatically down-loads the sensor calibration data. This
occurs when the power to the unit is first applied or after plugging the sensor data adapter into the instrument. The power
sensor and corresponding sensor data adapter have matching serial numbers for maintaining them as a matched pair.
EDIT DATA ACCESS CODE
Getting Started
3-15
Boonton 4240 Series RF Power Meter
The access code to enter the Edit Data menu is as follows:
Press the front panel switches in the following order:
<FREQ> <AVG> <AVG> <FREQ> <Sensor> <Enter>
Figure 3-15. Access Code
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3
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:
5
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:
0
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8
.
0
0
Q
0
.
0
0
R
2
3
.
0
0
R
-
7
5
.
0
#
1
0
0
Figure 3-16. Sensor Edit Data Menu Display
The parameter list will show TBLn (where n = 1, 2, 3, 4) when a serial number has not been entered for the corresponding
internal table. For example, TBL3 will be displayed if the serial number has not been previously entered for internal table 3. In
addition, the parameter list will show ADPTn (where n = 1, 2) if a serial number has not been entered for the table contained
within the sensor data adapter. For example, ADPT2 is displayed when the serial number has not been previously entered for
sensor data adapter 2.
To edit the sensor calibration data, move the cursor to the EDIT DATA function and press <Enter>. Scroll through the power
sensor serial numbers until the desired selection is displayed. Press <Enter> to proceed. Enter the access code to edit or
depress the <Menu> key to escape. (See Figure 3-15.)
Sensor Edit Data Menu. An example of the Edit Data menu is shown in Figure 3-16. Table 3-8 contains a description of the
commands and associated parameters.
Table 3-8 Sensor Edit Data Menu Functions
Function
Description
Parameters
Defaults
RTN
Returns the instrument to the
n/a
n/a
MODEL
Power sensor model number
0 to 99999
0
SER #
Power sensor serial number
0 to 99999
0
Table 3-8 Sensor Edit Data Menu Functions (continued)
3-16
Getting Started
Boonton 4240 Series RF Power Meter
Function
Description
Parameters
Defaults
DATE
Calibration date
MM/DD/YY
Where:
MM = 01 to 12
DD = 01 to 31
YY = 00 to 99
01/01/01
UPSCALE
Upscale linearity factors
Range : Factor
[0 to 6] : [0 to 9999]
5000
DOWNSCALE
Downscale linearity factors
Range : Factor
[0 to 6] : [-999 to 999]
0
FREQ C.F.
Brings the instrument to the
calibration factor menu
n/a
n/a
MAX FREQ
Power sensor's maximum
frequency
0, 100.00 GHz
18
MIN FREQ
Power sensor's minimum
frequency
0, 100.00 GHz
0.03
MAX POWER
Power sensor's maximum
[-99.99, 99.99] dBm
20
MIN POWER
Power sensor's minimum
power input
[-99.99, 99.99] dBm
-75
Linearity Factors. Seven upscale and downscale linearity factors are assigned to each power sensor. These values can be
viewed or edited by moving the cursor to the UPSCALE or DOWNSCALE command and pressing the <Enter> key. The
instrument will sequence through the linearity factors by pressing the up/down arrow keys. If a value is to be edited, scroll to
the desired linearity factor, use the right arrow key to move the cursor to the first digit in value field and then use the up/down
arrow keys to increment/decrement the number. Set the remaining digits in the same manner. If another value needs to be
changed, move the cursor back to the range field and use the up/down arrow keys to display the next value to be modified.
Press the <Enter> key when all of the changes have been entered.
FREQUENCY Calibration Factors. Up to 60 sensor frequency calibration factors can be entered for each power sensor.
Position the cursor to the FREQ C.F. command. Press the <Enter> key to advance to the Cal Factor menu. A sample of the
display is shown in Figure 3-17 and an explanation of the commands is shown in Table 3-9.
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1
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0
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-
0
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0
3
2
0
0
2
.
0
0
-
0
0
.
0
6
0
T
N
>
Figure 3-17. Frequency Cal Factor Menu Display
Getting Started
3-17
Boonton 4240 Series RF Power Meter
Table 3-9 FREQ Menu Functions
Function
Description
Parameters
Defaults
FREQ
Frequency
0.01 to 100.00 GHz
0.05
CAL
High frequency
calibration factor
-3.00 to 3.00 dB
0.00
The up/down arrow keys are used to scroll through the calibration factor table. Use the arrow keys to move to the desired field
and press the <Enter> key to change a value. The up/down arrow keys increment/decrement the value and the left/right arrows
keys select the digits. Press the <Enter> key when the desired value is displayed. Move the cursor to the RTN field or depress
the <Menu> key to return to the Sensor menu.
The instrument scans the sensor calibration table for a value that matches the operating frequency. Linear interpolation is used
if the operating frequency is between two of the table entries. To ensure proper operation, the calibration table must be entered
in ascending order and terminated in the last table entry with a zero (0) value for both the FREQ and CAL FACTOR. In
addition, new calibration values should be entered while adhering to the chronological order of the table. For example, to add
the -0.01 dB calibration factor at 3.5 GHz to the example shown in Figure 3-18, the calibration factors for items four through
six are re-entered.
Figure 3-18. Calibration Data Example
Save. Exiting the EDIT DATA menu displays the confirmation menu as shown in Figure 3-19. Move the cursor to YES to
save the edited parameters or NO to leave the data unchanged.
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Figure 3-19. Save Display
3-18
Getting Started
R
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Boonton 4240 Series RF Power Meter
3.3.3 FREQ Key.
The frequency of the signal being measured must be entered in order to use the stored high frequency calibration factors. The
instrument will then compute, display and apply the required correction factor to subsequent measurements.
The operating frequency may be set by first pressing the <FREQ> key. The instrument will advance to the Frequency menu as
shown in Figure 3-20. The frequency for Channel 1 is entered by positioning the cursor to the value field under the CH1
heading and pressing the <Enter> key. A value between 0.01 GHz and 100 GHz can be entered. The power on default is 0.05
GHz. Once the frequency is entered, the corresponding Cal Factor is displayed in dB beneath the frequency.
F
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8
.
0
0
0
0
2
.
5
0
0
0
0
.
1
0
-
0
0
.
0
2
Figure 3-20. Frequency Display
3.3.4 AVG Key.
The averaging time may be adjusted to optimize measurement speed and display stability. Averaging time, in seconds, can be
adjusted in 0.05 increments to a maximum of 20.00 seconds. The length of the filter in number of samples is shown on the
display.
To adjust the averaging time, press the <AVG> key and the instrument will display the screen as shown in Figure 3-21.
Position the cursor under the desired channel heading and press the <Enter> key. Use the arrow keys to set the desired value
and then press <Enter> to accept. Entering 00.00 selects the auto filtering Mode. This menu can be accessed to show the filter
setting in the auto mode.
T
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1
0
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5
0
2
1
0
C
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2
0
0
.
0
8
1
6
Figure 3-21. Averaging Time Display
3.3.5 Zero/Cal Key (single key press operation).
Zeroing should be performed when the unit is first warmed-up, a sensor has been changed or the instrument has drifted a
significant amount with respect to the signal level being measured. For large signals (measurements taken on range 4, 5, or 6),
this may be done once every several hours. For small signals, (measurements taken on range 0, 1, 2, or 3), zeroing should be
done before each measurement for optimum results. When zeroing is performed, the instrument calculates and stores zero
corrections for each range, and applies the corrections to subsequent measurements.
Assigning the <Zero/Cal> key as a single key press operation allows for a fast zeroing of the lowest hardware range to avoid
the longer zeroing process. When the Active Channel is measuring levels below approximately -50 dBm, and if the
measurement is settled, that is, if the filter is full, pressing the <Zero/Cal> key will take the displayed measurement as the zero
reference. This allows for faster and more acturate measurements of low level signals. If the measurement is not settled the
complete zeroing process of all ranges is performed.
Getting Started
3-19
Boonton 4240 Series RF Power Meter
The user may also perform a 0 dBm calibration by one key stroke of the Zero/Cal key. Simply connect the sensor to a 0 dBm
source (either by setting the internal 50MHz calibrator to 0 dBm or connecting to an external 0 dBm source) and press the
<Zero/Cal> key. The instrument detects that a 0 dBm signal is present and sets a calibration factor accordingly to indicate 0.00
dBm.
The Zero/Cal menu is displayed by first pressing the <Menu> key followed by the <Zero/Cal> key. From there the user
chooses the function (Zero, Fixed Cal, Auto Cal) and the channel to perform the calibration on. The Zero/Cal menu invokes
three commands as shown in Figure 3-22.
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Figure 3-22. Zero and Calibration Display
ZERO – performs zeroing of all hardware ranges of the selected channel.
FIXED CAL – the internal 50MHz calibrator is set to 0 dBm and a calibration is performed at that point. Fixed Cal may be
performed on any 0 dBm source other than the internal calibrator.
The built-in 50 MHz calibrator provides a convenient means for calibrating the instrument. Calibration can be performed any
time to assure accuracy.
AUTO CAL – improved sensor shaping can be realized by performing a step calibration using the 50 MHz Step Calibrator.
To perform an AutoCal, connect the sensor to be calibrated to the desired measurement channel and to the front panel CAL
OUT connector. Press the <Menu> key followed by the <Zero/Cal> key. The Zero/Cal menu will be displayed. Navigate the
cursor to the AUTO CAL line and select the channel to have the auto cal performed on. Press the <Enter> key to being the
AUTO CAL process. The instrument will return to the measurement window upon completion of the calibration.
3.3.6 REL Level Key (single key press operation).
Often relative measurements are required especially when measuring system gains and losses. One key press of the
<Ref/Level> key makes this job easier and faster to perform. Simply connect the active channel’s sensor to the input signal of
the system under test. Press the <Ref/Level> key and the reference level is set! Next connect the sensor to the system output
and read the gain or loss directly from the reference level measurement.
The REF Level menu is displayed by first pressing the <Menu> key followed by the <REF Level> key. From there the user
may SET (entering a value ) or LOAD (use the current channel measurement ) the reference level on either channel.
Press the <REF Level> key to enter a value or to use the current channel measurement for the reference level. The
measurement units will automatically change to dBr for logrythmic units or % for linear units for subsequent measurements.
An example of the instrument's display is shown in Figure 3-23.
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5
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Figure 3-23. Zero and Calibration Display
3-20
Getting Started
.
0
0
Boonton 4240 Series RF Power Meter
Table 3-10 Reference Level Menu Functions
Function
Description
Parameters
Defaults
dBm
Reference level value in Preset
mode.
-99.99 to 99.99 dBm
0
MODE
Reference level mode. "LOAD"
LOAD, SET, OFF
makes the current channel
measurement as the reference level.
The Set mode is used to select the
entered reference level. The Off mode
disables the reference level
adjustment.
OFF
To set a reference level, depress the <REF Level> key to display the REFERENCE LEVEL menu. Move the cursor to the
reference value for the appropriate channel. (Channel 1is default.) Depress the <Enter> key to initiate the editing process. Use
the arrow keys to edit the reference value in dBm. Once the desired value has been selected, depress the <Enter> key to leave
the editing function. To use this value as the reference, depress the <Down> arrow key to MODE, depress the <Enter> key for
mode selection and using the <Up> or <Down> arrow keys, select SET. Depressing the <Enter> key will place the appropriate
channel to the "dBr" mode of operation using the set value as the reference.
The instrument can also load the current measured value as the reference level. To do this, depress the <REF Level> key to
display the REFERENCE LEVEL sub-menu. Navigate the cursor using the arrow keys to the MODE selection of the desired
channel. Depress the <Enter> key for mode selection and using the <Up> or <Down> arrow keys, select LOAD. Depressing
the <Enter> key will place the appropriate channel to the dBr mode of operation using the measured value as the reference
level.
Getting Started
3-21
Boonton 4240 Series RF Power Meter
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3-22
Getting Started
Boonton 4240 Series RF Power Meter
4. Operation
This section provides detailed background information on various aspects of operation of the Model 4240. It is assumed that
the reader is familiar with the basic operating procedures covered in Section 3. This section covers the following topics:
Sensor calibration, Zeroing, Filtering, Noise, Dynamic range, Measurement time, High frequency accuracy, Chart recorder
operation and Waveform sensitivity.
4.1 Sensor Calibration
General. Two types of calibration are associated with the Model 4240 - instrument calibration and sensor calibration. The
instrument (less sensors) must be calibrated using a stable and accurate DC source, such as the Boonton Model 2510, to
ensure interchangeability of sensors. Instrument calibration procedures are covered in the Model 4240 Service Manual.
Sensor calibration data is of two types: linearity and high frequency calibration factors. Sensor calibration data for up to four
sensors can be stored in nonvolatile EEPROM plus each sensor data adapter contains the data matched to the corresponding
power sensor.
14-Point Linearity Data. Linearity data, also referred to as AC reference frequency linearity data, is supplied with the sensor
and can be manually entered into the non-volatile Tables or Adapters. For sensors ordered with the instrument, linearity data
is stored in the sensor data adapter before the instrument is shipped.
At the reference frequency (50 MHz, or 40, 60, or 94 GHz), each sensor has two gain factors for each range: upscale and
downscale points. Refer to Figure 4-1. The upscale points are in the range of 4000-7000, which is a gain correction factor.
Upscale points are calibrated at the factory at about 70% of full scale. The downscale number is an offset correction at about
25% of full scale. Thus, for a diode sensor (7 ranges), there are 14 points; for thermal sensors there are eight points. Ranges 0
and 1 share the same data points.
AutoCal. Initiates a multi-point sensor gain calibration of the selected sensor with the internal 50MHz step calibrator. This
procedure calibrates the sensor’s linearity at a number of points across its entire dynamic range. A sensor must be connected
to the channel input.
High Frequency Calibration Points. In addition to linearity data, there are high frequency calibration points. Calibration
points covering the entire sensor frequency range are supplied with each sensor. Below 1 GHz, the sensor response is flat,
and frequency calibration points need not be entered.
The Model 4240 provides space for up to 60 points for each sensor table. Frequency calibration points need not be in equal
frequency increments; however, the entry of data must be done in ascending order of frequency. For both diode and thermal
sensors, a calibration factor of 0 dB is implied at 0.00 GHz so that the instrument may be operated below the first data point.
4.2 Zeroing
The automatic zeroing routine of the instrument takes measurements on the lowest five ranges and applies these as correction
factors on subsequent measurements. Offsets in the sensor and input amplifiers are linearly corrected in the internal software.
Offsets on the highest ranges are below 0.02% of full scale, and do not need correction.
Input power to the sensor must be removed before the zeroing function is executed or an error message will be displayed. The
instrument will perform zeroing, however, if the signal is less than full scale on range 0. This feature provides a great deal of
offset capability for temperature effects without rezeroing the input amplifier hardware.
For full accuracy at low signal levels, power must be removed from the sensor several seconds before zeroing to allow the
sensor to settle. This is especially true if a large signal had been applied to the sensor in the previous 20 seconds or so
because of the dielectric absorption of the capacitors in diode sensors, and because of thermal retention in thermal sensors.
The error resulting from different input conditions can be determined from Figure 4-2 or 4-3, as applicable. The curves in
Operation
4-1
Boonton 4240 Series RF Power Meter
these figures show the decay of measured power after a large signal has been applied. The typical error that can be expected
by zeroing too quickly after application of a large signal is equal to the offset power at the time of zeroing.
The Model 4240 initiates zeroing when the ZERO command is invoked. The user must delay zeroing according to system
requirements when the sensors are used over a wide dynamic range. For example, if it is determined from the application that
five seconds are required from power off to the zeroing operation, then the user should wait five seconds after removing
power from the sensor before executing the zero command.
The zeroing time on each range has been optimized for speed and accuracy. Total zeroing time is approximately 20 seconds.
Zeroing should be done when the instrument is turned on, the sensor has been changed, or the instrument has drifted a
significant amount with respect to the signal being measured. For large signals (range 4, 5, or 6), this may be once every
several hours, if at all. For very small signals (range 0, 1, 2, or 3), for optimum results, zeroing be done immediately before
each measurement.
Figure 4-1. 14-Point Sensor Calibration
4-2
Operation
Boonton 4240 Series RF Power Meter
Figure 4-2 Diode Sensor Decay
Operation
4-3
Boonton 4240 Series RF Power Meter
Figure 4-3 Thermal Sensor Decay
4.3 Dynamic Range
The hold range mode is useful when it is known that the signal will vary over a certain limited range. (The hold range mode
is active when a specific instrument range, other than autorange, has been selected.) The dynamic range of this mode is
limited by the zero offset and the resolution, as shown in Figure 4-4. It can be seen from this figure that the useful dynamic
range is 20 dB if the error is to be kept below 0.1 dB. An asterisk is displayed before the channel when the measured value is
below the lower range limit indicating an uncalibrated measurement.
Figure 4-4. Extended Hold Range Mode
4-4
Operation
Boonton 4240 Series RF Power Meter
4.4 Filtering
The Model 4240 employs digital filtering (averaging of measurements) to reduce the noise floor of the instrument and to
stabilize measurements. The default values are optimized for speed and low noise under general conditions. Default values
for normal and fast modes are as follows:
Range
0
1
2
3
4
5
6
Normal (sec.)
2.8
0.8
0.8
0.8
0.8
0.8
0.8
Fast (sec.)
2.8
0.8
0
0
0
0
0
The filtering technique used is digital pipeline filtering, also referred to as circular filtering or moving average filtering. The
displayed measurement is simply an equally weighted average of the last x seconds worth of samples, where x is the filter
length in seconds. For purposes of noise and settling time, the number of samples is not important, but the time is important.
For example, if a three second filter is used, the noise is the same whether 60 or 600 samples are taken in that interval,
provided that the samples are taken above a certain rate. For this reason, filter selection in the Model 4240 is done on the
basis of seconds, rather than the number of samples.
The bottom end sensitivity of the instrument is limited by sensor noise. An RMS noise specification is valid since the sensor
noise and the amplifier noise are band-limited and Gaussian. The noise level, specified in picowatts at a certain filter length,
is sufficient to calculate the error due to noise at any signal level, for any filter, as shown in the discussion of noise that
follows.
4.5 Noise
Noise Reduction. The amount of noise reduction that can be realized has no theoretical limitation, except that drift enters
into the picture at filter lengths over 20 seconds. The digital filter has a bandwidth and rolloff curve just as any filter does; the
bandwidth can be reduced arbitrarily. The effective noise bandwidth is 0.469/t, where it is the filter length. For example, with
a filter length of 4 seconds, the equivalent noise bandwidth is 0.12 Hz.
Figure 4-5 is a nomograph showing the noise reduction that applies for various filter lengths, given the sensor noise with 2.8
second filtering. (This is the time for which diode sensor noise is specified.) Noise power is inversely proportional to the
square root of the filter length. Normally, noise power varies directly with filter bandwidth; however, because power sensors
are square-law devices (detected voltage is proportional to power), the noise power is proportional to the square root of the
bandwidth. This can be demonstrated with noise measurements. At very low filter lengths (less than 150 milliseconds),
however, the noise does not increase without bound for all sensors because the input amplifier noise is restricted with
hardware filters. This additional filtering is not shown in the nomograph.
Error Computation. Since the noise is Gaussian, both before and after filtering, statistics show the level of confidence
factor that can be associated with a given reading. (At medium and high power levels, the confidence factor is essentially
unity.) Figure 4-6 shows a typical set of samples and a typical error band specification of 2 sigma. Under these conditions,
95.4% of the readings will fall within +2 sigma.
Figure 4-7 shows the confidence factor for other error bands. The error band is expressed in pW, regardless of the power
level. (The percentage error band can also be calculated as shown below.) The RMS noise is taken from the sensor
specifications and modified as necessary for filter lengths other than 2.8 seconds. Knowing any two of the three parameters
(error band, RMS noise, and confidence factor), the third can be computed. For example, if the sensor RMS noise is 65 pW
and the confidence factor is to be 95.4%, the error band is 130 pW, single sided (+130 pW). If this were the case, at a
measurement level of 1300 pW the percent error band would be 10%, corresponding to about +0.44 dB.
Operation
4-5
Boonton 4240 Series RF Power Meter
4-6
Operation
Boonton 4240 Series RF Power Meter
Figure 4-5. Noise Reduction
Figure 4-6. Typical Error Band Specifications
Figure 4-7. Probability of Falling within an Error Band
Operation
4-7
Boonton 4240 Series RF Power Meter
Figure 4-8. Confidence Curves, 51013 Sensor with 2.8 Second Filter
4-8
Operation
Boonton 4240 Series RF Power Meter
Figure 4-9. Confidence Curves, 51013 Sensor with 10 Second Filter
Operation
4-9
Boonton 4240 Series RF Power Meter
Noise Error Examples. Figures 4-8 and 4-9 show the computed error for the 51013 diode sensor at different power levels,
for 2.8 and 10 second filters. To attain these results, the sensor must be at a stable temperature, and zeroing must be done
immediately before the measurement is taken.
Integration of Power. With long filtering, instrument readings may seem erroneous because the filter has not been cleared.
For example, with a 20 second filter, if a 2 second RF pulse is applied, the instrument display will indicate a nonzero level for
18 seconds after the pulse has terminated. Additional pulses will be integrated along with the first until, by the process of
selective deletion, the pulses are removed one at a time from the filter. Actually, measurement samples are deleted, not the
pulses, giving rise to a ramping effect at the instrument display/output. This is shown in Figure 4-10. In all senses, the filter
is a simple integrator.
Figure 4-10. Integration of Power
Clearing of Filter. When long filter times are used, it may become troublesome at times to wait for the filter to clear. If the
Auto filter function is selected, the filter is cleared after significant power changes, and filtering then resumes. Clearing can
also be accomplished by changing the filter length to any different value and then resetting it using the interface bus;
however, with bus operation, most of the trigger modes clear the filter at trigger time.
Partial Results. Measurement time is affected by the filter since valid readings to within a certain error band can be obtained
only when the filter is full. If the filter has been cleared, data is available at reduced accuracy immediately after the first 50
millisecond sample period. The filter uses the number of samples as a divisor when computing the average, and the
output/display does not ramp but homes in on the result instead as the samples accumulate.
4.6 Measurement Time
Step Response. The measurement time from a power input step is the sum of the overhead time and the length of the digital
filter, where the overhead time is defined as the time delay due to sensor response time and measurement software
(processing).
4-10
Operation
Boonton 4240 Series RF Power Meter
Continuous Response. Regardless of the overhead time or the digital filter length, the Model 4240 will output readings at a
maximum rate of about 200/second with the display operating. As the sensor and the digital filter settle, readings will ramp
up or down at that rate.
Overhead Time. Overhead time is <350 milliseconds for diode sensors and <450 milliseconds for thermal sensors under the
following conditions:
a. Settling to 99% or 0.04 dB of final power
b. Power step of 10 dB
c. Range does not change
d. Digital filter set to minimum
The power step may be upward or downward. Smaller power steps will decrease this time slightly; larger power steps in the
downward direction will increase the time significantly. A 40 dB downward step, for example, will take several seconds to
settle to 0.04 dB.
Digital Filter. The digital filter is a moving average or pipeline filter which simply integrates the readings over the last x
seconds, where x is the filter length. A step input to the filter will produce a linear ramp at the output, terminating when the
filter is full.
Default Filter Lengths. Although any filter length from 0 to 20 seconds may be chosen, default filter lengths are
programmed into the instrument for optimum general conditions. (Refer to Section 4.3 Filtering.) For diode sensors, the
range break-points are roughly in 10 dB steps, with the range 0 to 1 break-points at approximately -54 dBm.
Settled Measurement Time. In the free run settled mode, output data updates are held off until the measurements have
settled.
Fast Mode Measurement Time. The Fast Mode can be invoked over the bus to put the instrument into its fastest sampling
mode.
4.7 High Frequency Accuracy
Power measurements, particularly at high frequencies, have a number of uncertainties which generally arise from imperfect
SWRs. If all power sources and power meters had impedances that were resistive and equal to Zo (the characteristic
impedance of the measuring system), most problems would disappear. The incident, dissipated, and maximum available
powers would all be equal, and the indicated power would differ only by the inefficiency of the power sensor in converting
all dissipated power to indicated power. Tuning eliminates most of the SWR effects, but is cumbersome and is therefore
seldom done. The use of attenuator pads can mask imperfect SWRs, as can the use of a directional coupler to level the source
and reduce its reflection coefficient to a value equal to the directivity factor of the directional coupler. Boonton 51015 and
51033 power sensors have precision, built-in attenuators which improve the SWR over that of other power sensors.
When the complex coefficients of both an imperfect source and a power sensor are not known, but the maximum actual
SWRs of both are known, the maximum positive and negative uncertainties of the measured power, Pm, can be determined
from Figure 4-11. For example, if the SWR of the source is known to be 1.2 and the SWR of the power sensor is 1.25, the
uncertainty derived from Figure 4-11 is 2%.
Operation
4-11
Boonton 4240 Series RF Power Meter
Figure 4-11. Mismatch Uncertainties Chart
4.8 Waveform Sensitivity
Thermal sensors are insensitive to the waveform because they average RF power over many tens of milliseconds. Modulated
signals, non-sinusoidal waveforms, and even pulses can be detected without distortion of the measurement. Thermal sensors
are referred to as RMS responding.
4-12
Operation
Boonton 4240 Series RF Power Meter
Diode sensors are also RMS responding below about -20 dBm (-10 dBm and 0 dBm for attenuated models 51015 and
51033). This response characteristic is obtained because the sensors are dual diode types, and diodes respond in square-law
fashion at low and medium levels. This is not an approximation, but rather an inherent effect. This effect results from the fact
that the diodes do not turn on and off as switches, but behave as signal dependent resistors instead. Even with no signal input,
the diodes have a finite conductance, and this conductance is modulated on a cycle by cycle basis to give a net DC offset
proportional to the power.
The square-law response can be seen in Figure 4-12, where a 100% amplitude modulated signal is shown to have virtually no
effect on the measured power at low levels. Of course, frequency modulated and phase modulated signals can be measured at
any level, since the envelope of these modulated signals is flat. Frequency shift keyed (FSK) and quadrature modulated
signals also have flat envelopes and can be measured at any power level.
Figure 4-12. Error Due to AM Modulation (51013 Diode Sensor)
At higher power levels (above approximately -10 dBm for the 51013 sensor), the diodes operate as peak detectors. The
Model 4240 is software calibrated to calculate the RF power based on a shaping transfer function (RF to DC) for each sensor
type. However, only measurements of RF signals with flat envelopes (CW, FM, PM, FSK, quadrature, etc.) are valid in this
region and in the transition region from -20 dBm to -10 dBm.
A special provision is made for the case of rectangular pulses where the duty cycle (on-time percentage) is known and the top
level power of the pulse (pulse power) is to be measured. The duty cycle in percent is set into the DUTY entry in the
CHANNELS menu. For example, if the signal consists of pulses with a duty cycle of 25%, set DUTY to 25. This will add 6
dB to the displayed power and turn on the "Pk" indicator following the units.
Operation
4-13
Boonton 4240 Series RF Power Meter
Only the display is affected by the duty cycle calculation. The measurement process is subject to the same criteria discussed
above. For thermal sensor no correction is needed for level. However, pulse periods on the order of tens of milliseconds may
result in unstable readings because of inadequate averaging. If the filter time constant is too short, it can be increased by use
of the AVG function.
For diode sensors, the RMS power region extends up to -30 dBm with a gradual change to peak voltage response. For
accurate pulse power measurement, the power meter should read an average power of -30 dBm or less. This is the power
indication when the duty cycle is set to 100%. Somewhat useful measurements can be made up to -20 dBm average power,
but the uncertainty will typically be at least +1dB.
Extra care should be taken when using the pulse power feature to avoid overload damage to power sensors. Pulses with small
duty cycle have a very large peak to average power ratio. The average responding power meter may have a small indicated
power, but the peak signal at the sensor diode or thermal element may easily exceed the maximum ratings.
4.9 Chart Recorder Operation
The chart recorder output is a DC voltage from 0 to 10 volts. In the Watts mode, the output voltage is equal to the digits
displayed on the main data display divided by 1100 times 10. In the dBm or dBr modes, the output voltage is directly
proportional to the ratio of the difference of the measured value and the sonsor’s lower limit to the full dynamic range of the
sensor times 10. For example if the default upper limit is 23 dB and the lower limit is -75 dB for a particular sensor then at 0
dBm the corresponding Recorder Output voltage would be: (0 – (-75) * 10) / (23 – (-75)) = 750 / 98 = 7.65 volts. The
sensitivity over a 10 dB range would be (10 * 10) / 98 = 1.02 volts. Refer to Section 3.3.2 Sensor Key to locate the upper and
lower limits of the sensor in use in determining the expected Recorder Ouput response.
The output impedance is 9.06 kilohms, which gives the user the option of loading it with 1 kilohm, thereby reducing the full
scale output to 1 volt. The normal 12-bit resolution is still maintained with this method. With a 1 megohm load, the circuit is
essentially open and the error is small. Absolute accuracy is +5%.
4.10 Bar Graph Operation
The meter presents the power proportionally in the following manner.
Watts Mode. The meter follows the digital display as a percentage of the full scale. The bar graph consists of 100 segments
resulting in a 1% resolution. A main data display of 1100.0 µW drives the meter to 100 percent of full scale while a display
of 561.0 µW drives the meter to 51 percent of full scale. The meter reads full scale at 10 dB increments.
dBm Mode. The meter follows the digital display as a percentage of the full scale. The bar graph consists of 100 segments
resulting in a resolution of 0.1 dB/segment. A main data display of 0.00 dBm (or any 10 dB increment) drives the bar graph
to zero percent of full scale while 5.00 dBm and 9.99 dBm drives the meter to 45 percent and 90 percent of full scale
respectively. A value of –7 dBm would drive the meter to 27 percent of full scale while a value of –2 dBm would drive the
meter to 72 percent of full scale.
dBr Mode. Selecting the dBr mode positions the bar graph to 50 percent of full scale when the digital display reads 0 dBr.
The analog meter thereafter reads 100 percent of full scale at +5 dBr or more and zero percent of full scale at –5 dBr or less.
4-14
Operation
Boonton 4240 Series RF Power Meter
5. Remote Operation
5.1 GPIB Configuration
The 4240 GPIB interface is configured using the Menu > SETUP > IEEE menu. The primary listen/talk address (MLTA) can
be set to any value from 1 to 30 inclusive. The value assigned must be unique to each GPIB device. Secondary address is
not implemented.
To inform the instrument that a message has been completed, the bus controller must end all messages with a terminating
character and/or EOI control signal. The Model 4240 can be programmed for several combinations of terminating characters
as required by the controller employed. Selection of terminating characters is accomplished via the Menu > SETUP > IEEE
menu. There the instrument can be programmed for individual end of string characters in both listener and talker modes as
well as independently enabling the end or initiate control signal.
5.2 RS-232 Configuration
RS-232 interface is also available on the Model 4240. The command set and data transfer protocol are nearly identical to
those for IEEE. The Menu > SETUP > RS232 commands are used to configure the RS-232 interface to comply with the
terminal in use. Setting the end-of-string character and SRQ Mask is accomplished by using the EOS Talker/Listener and
SRQ Mask commands respectively.
Entering the Remote Mode. The Model 4240 enters the remote mode when the ASCII "SI" character (hexadecimal
0F/CTRL O) is received. In the remote state, the front panel keyboard is disabled, except for the <Menu> key which serves as
the return to local function. The display will show the REM indicator on the last line and enable the TLK, LSN and SRQ as
appropriate.
Returning to Local Mode. The instrument will return to the local state when; a) The <Menu> key is pressed or b) The
ASCII "SO" character (hexadecimal 0E/CTRL N) is received.
Note
The instrument must be placed in the remote state for it to respond to data messages. It is not possible to
store data in the local state for execution in the remote state.
Talk Operations. The Model 4240 can be requested to talk in two ways. The "??" mnemonic is available for requesting data
via the RS-232 port. Immediately after receiving this mnemonic, the instrument responds by transmitting data based on the
current talk mode. For example, the following interactive sequence causes the Model 4240 to transmit the measurement with
the associated units (4230 IEEE Emulation mode):
Note
Terminal Sends
O (CTRL O/hexadecimal 0F)
Model 4240 Response
REM displayed on bottom line, indicating remote operation.
DB TM1 ??<ENTER>
Set measurement to dBm, set the talk mode to 1 (talk measurement with units).
Data returned: “0,-3.00 dBm” - indicating no error at -3 dBm.
<ENTER> means transmit end-of-string as defined via the Menu > SETUP > RS232 > EOS LSTN
parameter (typically CR).
Remote Operation
5-1
Boonton 4240 Series RF Power Meter
Additionally, the ASCII "DC2" character (hexadecimal 12/CTRL R) will cause the instrument to immediately transmit data
based on the current talk mode. Continuing the above example:
Terminal Sends
TM0 <ENTER>
Model 4240 Response
Set the talk mode to send Floating Point Measurements.
R (CTRL R/hexadecimal 12)
Talk the error flag and the measurement in floating point notation.
Data returned: “0,-3.00” - indicating no error and the power is -3 dBm.
The rules for number and data strings are the same as for the IEEE-488 interface. Number formats are free form and data
strings are case insensitive.
5.3 SCPI Language
The 4240 Series instruments may be remotely controlled using commands that follow the industry-standard SCPI
programming conventions. The default language is:
SYSTem:LANGuage SCPI
All of the functions of the 4240 Series are accessible remotely via SCPI commands.
5.3.1 SCPI Structure
The SCPI instrument model defines a hierarchical command structure based on “command nodes”. Each node may contain
commands or names of a next-level command node. Each command is formed of a series of keywords joined together, and
delimited by a colon “:” character. The command begins with a colon at the “root node”, and traverses downwards through
the command tree to form a specific command. This structure is very similar to a DOS file system, where the file system
begins at the root level (“:”), and each directory (SCPI subsystem) may contain a list of files (SCPI commands) and lowerlevel directories. To execute an individual command, the entire command name (“path”) must generally be speficied,
although there are several shortcuts available to reduce the command string length.
SCPI subsystems or command groups are usually aligned with instrument functions, and the standard provides a number of
pre-defined subsystems that can be used for most instrument types. For example, the top level SENSe subsystem groups
commands that are related to sensing signals (detection, amplification, digitization, linearization), while the OUTPut
subsystem contains commands that control output functions of the instrument such as voltage output or controlling an RF
reference output.
5.3.2 Long and Short Form Keywords
Each command or subsystem may be represented by either its full keyword, or a short form of that keyword. The short form
is typically the first several characters of the full name, although this is not necessarily the case. The short form of each
keyword is identified in this manual by the keyword characters shown in UPPERCASE, while the long form will be shown in
mixed case. For example, the short form of “CALCulate” is “calc”, while the long form is “calculate”. Long form and short
form commands may be used interchangeably, but only the exact forms are permitted – intermediate length commands will
not be recognized. Sending “CALCUL” will cause an error.
Note that not all keywords have long forms – in this case, the entire keyword will be shown in uppercase.
While uppercase and lowercase text is used to identify keywords, SCPI is generally case-insensitive, so it is acceptable to
send uppercase, lowercase or mixed case keywords to the instrument. The only exception is when a command accepts a
literal string argument. In this case, quotes may be used to delimit a string of user-defined case.
5.3.3 Subsystem Numeric Suffixes
Certain subsystems, such as the SENSe or CALCulate subsystems in the 4240 Series, often exist as more than one instance
(often called a “channel” in an instrument). In this case, an optional numeric suffix may be used to define the channel. If this
5-2
Remote Operation
Boonton 4240 Series RF Power Meter
suffix is not present, the default channel is assumed. For example, SENSe or SENSe1 defines operation affecting the
instrument’s “Channel 1” measurement path, while SENSe2 commands will apply to channel 2.
5.3.4 Colon Keyword Separators
The colon (“:”) character is used similar to the way a slash or backslash is used in a filesystem. Prefixing a command string
with a colon resets parsing at the root command level, and a colon must separate each keyword in the command. Beginning a
new line always resets parsing to the root level, so the leading colon is optional if the command is the first command on a
line.
5.3.5 Command Arguments and Queries
Many commands require arguments. In this case, the entire command string is sent, followed by the argument. A space is
used to separate the command from the argument. For example, “SENSe:CORRection:DCYCle 25.0” sets duty cycle
correction to a value of 25.0. Arguments may be numeric, or alphanumeric. If a command requires more than one numeric
argument, the arguments must be sent as a comma delimited list.
To read the current value of a particular parameter, the Query Form of its command may be used. A command query is
formed by appending a question-mark (“?”) suffix to the command instead of an argument list. There should not be any
whitespace between the command and the suffix. For example, “SENSe:CORRection:DCYCle?” queries the duty cycle
correction parameter, and causes the instrument to return its current value.
5.3.6 Semicolon Command Separators
The semicolon (“;”) character is used to separate multiple commands on a single line. However, the parsing path is affected
when more than one command is combined on a line. As noted previously, the first command of a line is always referenced
to the root level whether or not the command is prefixed by a colon. However, for the second and succeeding commands, the
parsing level is NOT reset to the root level, but rather referenced from the current node. This allows the parser to remain at
the current node, and execute other commands from that node without resending the entire node string. For example, the
following multi-command strings are equivalent:
:SENSe:CORRection:DCYCle 25.0; :SENSe:CORRection:CALFactor 2.12;
(two full-path commands)
:SENSe:CORRection:DCYCle 25.0; CALFactor 2.12;
( second command referenced to CORRection node)
SENSe:CORRection:DCYCle 25.0; CALFactor 2.12;
(leading colon omitted from first command)
If a command does not belong to the same subsystem as the preceding command on the same line, then its full path must be
specified, including the colon prefix.
5.3.7 Command Terminators
All SCPI command strings transmitted to the instrument must be terminated. For commands sent via the GPIB bus, any
character with the IEEE488 EOI (End-Or-Identify) control line asserted may be used as a terminator. This may be the last
letter of the command, query or argument. Optionally, a CR (ASCII 13) and/or LF (ASCII 10) may be included.
For commands sent via the RS-232 interface a CR and/or LF must be included to match the desired protocol.
When the terminating condition is met, the SCPI path is first reset to the root level, and the received message is then passed
to the SCPI parser for evaluation.
5.3.8 4240 Series SCPI Implementation
The SCPI Model of the 4240 provides a single or dual SENSe sub-system to handle sensor input and a matching single or
dual CALCulate sub-system to process the data obtained from the sensors into useful results. The CALibration sub-system is
used to calibrate power sensors. Channel dependent commands end with a number to indicate the desired channel as follows:
Remote Operation
5-3
Boonton 4240 Series RF Power Meter
Examples:
:CALCulate:STATe ON
Turn on measurement channel 1 (default channel number)
:CALCulate1:STATe ON
Turn on measurement channel 1 (specified channel number)
:CALC:STAT ON
Turn on measurement channel 1 (short form, default chan #)
:CALC1:STAT ON
Turn on measurement channel 1 (short form, specified chan #)
:CALCulate:STATe?
Query the state of measurement channel 1 (default chan #)
:CALC:STAT?
Query the state of channel 1 (short form, default chan #)
:CALCulate1:STATe?
Query the state of measurement channel 1 (specified chan #)
:CALC1:STAT?
Query the state of channel 1 (short form, specified chan #)
:SENSe:CORRection:OFFSet 0.42
Set channel 1 offset correction to 0.42 dB (chan units dBm)
In the discussion and tables below, the following notation will be used:
Command name long and short form:
SYSTem
Optional command name in brackets:
SYSTem:ERRor[:NEXT]?
Command with channel dependence:
CALCulate[1|2]:STATe OFF
Default channel 1:
CALibration:AUTO
Explicit channel 1:
CALibration1:AUTO
Select channel 2:
CALibration2:AUTO
Short Form:
CAL2:AUTO
Command which takes numeric argument: SENSe1:AVERage <numeric value>
Same command; query:
SENSe1:AVERage?
Command with literal text argument:
CALCulate1:UNITs <character data>
Command with no query form:
*CLS
Command with query form only:
FETCh1:CW:POWer?
SYNTAX NOTES
Square brackets [ ] are used to enclose the list of valid channels for a command, or a list of command options separated by
the vertical separator bar | character. This character is for syntax only, and is not to be entered as part of the command. By
default, if no channel number is specified, Channel 1 is selected.
A literal argument denoted by <character data> indicates a word or series of characters, which must exactly match one of
the choices for the command. An argument denoted by <numeric value> requires a string which, when converted to a
number, is within the range of valid arguments. Numerical values can generally be in any common form including decimal
and scientific notation. <Boolean> indicates an argument which must be either true or false. Boolean arguments are
represented by the values 0 or OFF for false, and 1 or ON for true. Queries of Boolean parameters always return 0 or 1.
Curly braces { } are used to enclose two or more possible choices for a mandatory entry, separated by the comma character.
One of the enclosed options MUST be inserted into the command, and the braces are not to be entered as part of the
command.
5-4
Remote Operation
Boonton 4240 Series RF Power Meter
5.4 Basic Measurement Information
The easiest way to obtain a reading is by use of the MEASure command. This command initiates one complete measurement
sequence which includes a default configuration. Examples are:
MEAS1:POWER?
To return the average power of channel 1, or
MEAS1:VOLTAGE?
To return the average voltage of channel 1.
For finer control over the measurement, individual configuration and function commands should be used. Readings are
obtained using the FETCh[ ]? command for current data or the READ[ ]? command for fresh data.
Readings are in fundamental units as set by the CALCulate[1|2]:UNIT command. Each reading is preceded by a condition
code, which has the following meaning:
-1
Measurement is STOPPED. Value returned is not updated.
0
Error return. Measurement is not valid.
1
Normal return. No error.
2
An Under-range condition exists.
3
An Over-range condition exists.
With the INITiate:CONTinuous OFF condition, a single measurement cycle is started by use of the
INITiate[:IMMEDIATE] command, where bracketed commands are optional. Multiple triggered measurement cycles are
enabled by INITiate:CONTinuous ON.
5.4.1 Service Request
Service requests provide a means to signal the host that a particular event or group of events have occurred in the instrument.
Service requests are controlled by the Status Byte Register and the Service Request Enable Register. The Service Request
Enable Register is a bit mask that determines which summary bits of the Status Byte Register can cause a request for service
to be sent to the Controller. The summary bits of the Status Byte are the MAV, or Message Available bit, and three bits from
event driven registers. The first of these is the Standard Event Status Register. The bits of this register are set and latched by
specific events within the instrument and cleared when the register is read. The remaining two registers are the Operation
Status Register and the Questionable Status Register. These two registers are similar to the Standard Event Status Register
but have the additional capability to detect changes in the individual bits of the associated register’s condition register. The
bits are not only selected by a mask register, but a change in a selected bit, either a high to low, low to high or either
transition, can be specified by transition mask registers.
The Status Byte is read by the *STB? command. The bit enable mask is set by the *SRE command and read by the *SRE?
query. The Standard Event Status Register is read by the *ESR? Command and the bit enable mask is set by the *ESE
command or read by the *ESE? Command.
The Operation Status Register is read by the STATus:OPERation:CONDition? command. The transition masks are set by
the STATus:OPERation:NTransition and STATus:OPERation:PTransition commands. The bit enable mask is set by the
STATus:OPERation:ENABle command and read by the STATus:OPERation:ENABle? query. The Operation Event
Register is read by the STATus:OPERation:EVENt? query.
The Questionable Event Status Register has the same structure as the Operation Status Register. Refer to the command
descriptions that follow for detailed information.
Remote Operation
5-5
Boonton 4240 Series RF Power Meter
5.5 SCPI Command Reference
This section contains a list of all SCPI remote commands accepted by the 4240 Series. The list is grouped by SCPI subsystem
or IEEE488.2 function, and includes a detailed description of each command.
5.5.1 IEEE 488.2 Commands
The purpose of IEEE488.2 commands is to provide management and data communication instructions for the system by
defining a set of “*” commands (an asterisk followed by a three character code). These commands allow device control and
status monitoring, and are the basis for some of the commands of the SCPI STATus subsystem (see Section 5.5.12).
*CLS
Description:
Clear Status command. This command resets the SCPI status registers (Questionable Status and
Operation Status), the error queue, the IEEE488.2 Status Byte (STB) and Standard Event Status
(ESR) registers, and the measurement.
Syntax:
*CLS
Argument:
None
Description:
Set or return the Standard Event Status Enable Register. The mask value in this register is used to
enable bits of the Standard Event Status Register that are or’ed together to form the ESB summary
bit in the instrument Status Byte. When a mask bit is set, and the corresponding ESR bit goes
true, an SRQ will be generated, provided the Event Status Summary bit (ESB, bit 5) is enabled in
the SRE register. No SRQ can be generated for that condition if the mask bit is cleared. To clear
the entire Standard Event Status Enable Register, send *ESE = 0. See the *ESR command for bit
assignments. This register is not cleared by *CLS, *RST or DCLR.
Syntax:
*ESE <numeric value>
Argument:
<numeric value> = 0 to 255
*ESE
5-6
Remote Operation
Boonton 4240 Series RF Power Meter
*ESR?
Description:
Return the current value of the Standard Event Status Register, then clear the register. This register
has bits assigned to a number of possible events or conditions of the instrument. When the event
occurs, the corresponding bit is latched. The register value is read using this command.
Individual bits may be enabled or disabled for SRQ generation using the ESE mask (see *ESE
command). The following table shows the bit assignments in the Standard Event Status Register:
Bit Value
0
1
2
3
4
5
6
7
1
2
4
8
16
32
64
128
Definition
Operation Complete Flag
Not used
Not used
Device Dependent Error
Not used
Command Error
Not used
Not used
1 = all current operations have completed execution.
1 = the instrument encountered a device dependent error.
always returns 0
1 = a remote interface command error exists.
always returns 0
always returns 0
Syntax:
*ESR?
Returns:
Current Value of Event Status Register (0 to 255)
Description:
Return the instrument identification string. This string contains the manufacturer, model number,
serial number and firmware version number.
Syntax:
*IDN?
Returns:
< Mfgr, Model#, Serial#, Version# >
Description:
Clears the OPC (Operation Complete) status flag. This command is issued before the command to
be checked for completion. After this, the flag may be queried by *OPC? until a value of one is
returned, indicating the command has completed. Note that the query is not a true query - a value
of zero will never be returned.
Syntax:
*OPC
Argument:
None
Description:
This command examines the OPC (Operation Complete) status flag and returns a “1” if all
pending operations are complete. If pending operations are not yet complete, it does not return.
Syntax:
*OPC?
Returns:
Always returns 1 to indicate operations complete. Otherwise, does not return.
*IDN?
*OPC
*OPC?
Remote Operation
5-7
Boonton 4240 Series RF Power Meter
*OPT?
Description:
Return the status of Channel 1 and Channel 2 followed by a list of installed options.
Syntax:
*OPT?
Returns:
<f1, f2, f3, f4, opt1, opt2, …> : f1 – Chan 1 installed?, f2 – Chan1 sensor present?, f3 – Chan 2
installed?, f4 – Chan 2 sensor present?, opt1, opt2, etc. (option list may be empty).
Description:
Set the instrument to a known “default” configuration. Set measurements to STOP. Set the sensor
temperature offset flag to FALSE, set the SCPI file over-write permission to FALSE, turn the
internal Calibrator output OFF and clear the error queues. System communication parameters are
not changed. Instrument measurement functions are set their default values (See Table 3-3,
Initialized Parameters).
Syntax:
*RST
Argument:
None
Description:
Set or return the mask value in the Service Request Enable Register. This value is used to enable
particular bits for generating a service request (SRQ) over the GPIB when certain conditions exist
in the Status Byte register. When a mask bit in the SRE Register is set, and the corresponding
STB register bit goes true, an SRQ will be generated. No SRQ can be generated for that condition
if the mask bit is clear. The bits in the Status Byte register are generally summary bits, which are
the logical OR of the enabled bits from other registers. See the *STB command for bit
assignments.
Syntax:
*SRE <numeric value>
Argument:
<numeric value> = 0 to 255
*RST
*SRE
5-8
Remote Operation
Boonton 4240 Series RF Power Meter
*STB?
Description:
Return the current value of the Status Byte register. This register has bits assigned to a number of
possible events or conditions of the instrument. The register value may be read using this
command, or may be used to generate a service request (SRQ) over the GPIB when certain
conditions exist. Individual bits may be enabled or disabled for SRQ generation using the SRE
mask (see *SRE command). Note that the bits in the Status Byte register are generally summary
bits, which are the logical OR of the enabled bits from other registers. The following table shows
the bit assignments in the Status Byte register:
Bit Value
0
1
2
3
4
5
6
7
1
2
4
8
16
32
64
128
Definition
Not used
Not used
Error/Event queue status
QUEStionable Status Summary
Message AVailable flag bit
Event Status Summary
MSS Summary Status
OPERation Status Summary
1 = there is at least one event in the error queue.
1 = an enabled QUEStionable condition is true.
1 = an output message is ready to transmit.
1 = an enabled Event Status condition is true.
1 = at least one other Status Byte bit is true.
1 = an enabled OPERation condition is true.
Syntax:
*STB?
Returns:
Current Value of Status Byte register (0 to 255)
Description:
Simulate the bus trigger command. This command has the same effect as the GPIB command
GET (Group Execute Trigger), except it must be parsed and decoded before the action takes place.
There is no query form of this command.
Syntax:
*TRG
Argument:
None
Description:
Self-test query. This command initiates a self-test of the instrument, and returns a result code
when complete. The result is zero for no errors, or a signed, 16-bit number if any errors are
detected.
Syntax:
*TST
Returns:
Error Code
Description:
Wait command. This command insures sequential, non-overlapped execution. The 4240 always
operates in non-overlapped, sequential mode, therefore this command is accepted as valid, but
takes no action.
Syntax:
*WAI
Argument:
None
*TRG
*TST?
*WAI
Remote Operation
5-9
Boonton 4240 Series RF Power Meter
5.5.2 CALCulate Subsystem
The CALCulate group of the command subsystem is used to configure post acquisition data processing. Functions in the
CALCulate subsystem are used to configure the measurement mode and control which portions of the acquired measurement
data is used and how it is processed to yield a finished measurement. In addition to measurement mode, CALCulate is used
to define mathematical operations, measurement units, and limit monitoring. The numeric suffix of the CALCulate program
mnemonic in the CALCulate commands refers to a processing and display “channel”, that is CALCulate1 and CALCulate2
represent the power meter’s Channel 1 and Channel 2 functions. The CALCulate commands generally DO NOT affect the
data acquisition portion of the measurement (see the SENSe subsystem, Section 5.5.11 ). In a signal-flow block diagram, the
CALCulate block operations will follow those of the SENSe block. Note that CALCulate2 commands will generate an error
if used with a single channel Model 4241.
CALCulate:LIMit:CLEar[:IMMediate]
Description:
Clear all latched alarms for the selected channel.
Syntax:
CALCulate[1|2]:CLEar[:IMMediate]
Argument:
None
CALCulate:LIMit:FAIL?
Description:
Returns the status of all limit alarms for the specified channel in five flags. The first flag is the
logical sum of the remaining four. They are: low-limit active, high-limit active, low-limit latched
and high-limit latched. Active means that the limit is exceeded when the command is executed;
Latched means that the limit has been exceeded since the last limit clear command.
Syntax:
CALCulate[1|2]:LIMit:FAIL? <Boolean1>, … <Boolean5>
Returns:
<Boolean1> = summary, <Boolean2> = low-limit active, <Boolean3> = high limit active,
<Boolean4> = low-limit latched, <Boolean5> = high-limit latched
CALCulate:LIMit:LOWer[:POWer]
Description:
Set or return the lower limit power level for the selected channel. This limit is used for level
alarms. When the measured average power is below the lower limit, a down arrow ▼ will appear
on the display to the left of the measured value, and flag bits are set in the alarm register which
may be accessed using CALCulate:LIMit:FAIL? query and CALCulate:LIMit:CLEAR
commands.
Syntax:
CALCulate[1|2]:LIMit:LOWer[:POWer] <numeric value>
Argument:
<numeric value> = -99.99 to +99.99 dBm
5-10
Remote Operation
Boonton 4240 Series RF Power Meter
CALCulate:LIMit:UPPer[:POWer]
Description:
Set or return the upper limit power level for the selected channel. This limit is used for level
alarms. When the measured average power is above the upper limit, an up arrow ▲ will appear on
the display to the left of the measured value and flag bits are set in the alarm register which may
be accessed using CALCulate:LIMit:FAIL? query and CALCulate:LIMit:CLEAR commands.
Syntax:
CALCulate[1|2]:LIMit:UPPer[:POWer] <numeric value>
Argument:
<numeric value> = -99.99 to +99.99 dBm
CALCulate:LIMit:LOWer:STATe
Description:
Set or return the lower limit alarm system state for the selected channel. When the lower alarm is
enabled (ON), the measured average power is compared to the preset lower power limit, and the
error flag is set if out of range. When OFF, no action occurs if the power is out of range.
Syntax:
CALCulate[1|2]:LIMit:LOWer:STATe <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
CALCulate:LIMit:UPPer:STATe
Description:
Set or return the upper limit alarm system state for the selected channel. When the upper alarm is
enabled (ON), the measured average power is compared to the preset upper power limit, and the
error flag is set if out of range. When OFF, no action occurs if the power is out of range.
Syntax:
CALCulate[1|2]:LIMit:UPPer:STATe <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
CALCulate:LIMit[:BOTH]:STATe
Description:
Set or return the combined upper and lower limit alarm system state for the selected channel.
When alarms are enabled (ON), the measured average power is compared to the preset upper and
lower limits, and the error flags are set if out of range. When OFF, no action occurs if the power
is out of range. A query returns 1 if either the upper or lower limit alarm is enabled. A query
forces both upper and lower ON if either is enabled.
Syntax:
CALCulate[1|2]:LIMit:[BOTH]:STATe <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
Remote Operation
5-11
Boonton 4240 Series RF Power Meter
CALCulate:MATH:ARGA
Description:
Set or return the first argument to be used for channel math operations.
Syntax:
CALCulate:MATH:ARGA <character data>
Argument:
<character data> = { CH1, CH2 }
CALCulate:MATH:ARGB
Description:
Set or return the second argument to be used for channel math operations.
Syntax:
CALCulate:MATH:ARGB <character data>
Argument:
<character data> = { CH1, CH2 }
CALCulate:MATH:DATA?
Description:
Returns the channel math result.
Syntax:
CALCulate:MATH:DATA?
CALCulate:MATH:OPERator
Description:
Set or return the channel math operator.
Syntax:
CALCulate:MATH:OPERator <character data>
Argument:
<character data> = { CH_SUM, CH_DIFF, CH_RAT }
CALCulate:MODe
Description:
Set or return the system remote measurement mode. These measurement modes are only available
under bus control. NORMal is the default mode of operation at approximately 20 readings per
second. FAST returns data at over 200 readings per second. FILTered will only return data when
the filter is full. FILTered works best when INITiate:CONTinuous is OFF and a trigger is issued.
In this case the measurement will not be returned until the filter is full. When the instrument is
returned to local the MODE defaults to NORMal.
Syntax:
CALCulate:MODe <character data>
Argument:
<character data> = { NORMal, FAST, FILTered }
5-12
Remote Operation
Boonton 4240 Series RF Power Meter
CALCulate:REFerence:COLLect
Description:
For the selected channel, make the current power the reference level for ratiometric measurements,
replacing the previous reference level.
Syntax:
CALCulate[1|2]:REFerence:COLLect
Argument:
None
CALCulate:REFerence:DATA
Description:
For the selected channel, set the power level specified by the argument as the reference level for
ratiometric measurements, replacing the previous reference level.
Syntax:
CALCulate[1|2]:REFerence:DATA <numeric value>
Argument:
<numeric value> = -99.99 dBm to +99.99 dBm
CALCulate:REFerence:STATe
Description:
For the selected channel, sets or returns the state of the ratiometric measurement mode. The
ratiometric mode causes the reading to be expressed relative to a user specified value. The
resulting reading will have units of dBr (dB relative) or percentage depending upon the type of
units in use. When the ratiometric mode is disabled, the reading will be restored to express a
power or voltage level.
Syntax:
CALCulate[1|2]:REFerence:STATe <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }, accepts all, returns OFF, ON
CALCulate:STATe
Description:
Set or return the measurement state of the selected channel. When ON, the channel performs
measurements; when OFF, the channel is disabled and no measurements are performed.
Syntax:
CALCulate[1|2]:STATe <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }, accepts all, returns OFF, ON
Restrictions:
Only pertains to channel 2 of the 4242. Channel 1 cannot be individually disabled. 1 is accepted as
the default argument but no action is taken.
CALCulate:UNITs
Description:
Set or return units for the selected channel. For power sensors, voltage is calculated with
reference to the sensor input impedance. Note that for ratiometric results, logarithmic units will
always return dBr (dB relative) while linear units return percent.
Syntax:
CALCulate[1|2]:UNITs <character data>
Argument:
<character data> = {DBW, DBMW, DBUW, DBNW, WATTS, VOLTS, DBV, DBMV, DBUV,
DBNV}
Remote Operation
5-13
Boonton 4240 Series RF Power Meter
5.5.3 CALibration Subsystem
The CALibration group of commands is used to control automatic zero offset and linearity adjustments to the RF power
sensor and the channel to which it is connected. Zero offset adjustment can be performed at any time if no RF signal is
applied to the sensor. Linearity calibration requires that the sensor be connected to the instrument’s built-in RF calibrator.
The numeric suffix of the CALibration commands refers to a measurement channel, that is CALibration1 and CALibration2
refer to CH1 and CH2 input channels, respectively.
Note that CALibration2 commands will generate an error if used with a single channel Model 4241. Also note that although
CALibration commands do not accept any arguments, all have a query form, which returns a status code upon completion of
the zero or calibration process. This allows the user to determine when the process has completed, and whether or not it was
successful.
CALibration:AUTOcal
Description:
Performs a multi-point sensor gain calibration of the selected sensor with the internal 50 MHz
calibrator. This procedure calibrates the sensor’s linearity at a number of points across its entire
dynamic range.
Syntax:
CALibration[1|2]:AUTOcal[?]
Returns:
0 if successful, 1 otherwise (using query form only)
CALibration:FIXedcal
Description:
Performs a calibration at a fixed frequency and level. Fixed-cal does provide for automatic control
of the internal 50 MHz calibrator setting the output level to 0 dBm prior to performing the
calibration. The RF output level of any other source in use must be set to 0 dBm by the user.
Fixed-cal assumes that a valid Zero has already been performed.
Syntax: CALibration[1|2]:FIXedcal[?]
Returns:
0 if successful, 1 otherwise (using query form only)
CALibration:ZERO
Description:
Performs a zero offset null adjustment. The sensor does not need to be connected to any calibrator
for zeroing – the procedure is often performed in-system. However, this command will turn off
the internal calibrator prior to zeroing to avoid the need to perform this step explicitly.
Syntax:
CALibration[1|2]:ZERO[?]
Returns:
0 if successful, 1 otherwise (using query form only)
5-14
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.4 DISPlay Subsystem
The DISPlay group of commands is used to control the selection and presentation of measurements.
DISPlay:ACTive[?]
Description:
Set or return the active channel for talk commands.
Syntax:
DISPlay:ACTive <numeric value>
Argument:
<numeric value> = 1 to 2
DISPlay:CLEar
Description:
Clear all data buffers for CH1 and CH2. Clears averaging filters to empty. Does NOT clear errors.
Syntax:
DISPlay:CLEar
DISPlay:LIN:RESolution
Description:
Set or return the display resolution for linear power and voltage readings. The number of
significant digits displayed is equal to the argument. This command also sets the resolution of
measurements returned in remote mode.
Syntax:
DISPlay[1|2]::LIN:RESolution <numeric value>
Argument:
<numeric value> = 3 to 5
DISPlay:LOG:RESolution
Description:
Set or return the display resolution for logarithmic power and voltage readings. The number of
decimal places displayed is equal to the argument. This command also sets the resolution of
measurements returned in remote mode.
Syntax:
DISPlay[1|2]::LOG:RESolution <numeric value>
Argument:
<numeric value> = 1 to 3
DISPlay:LABel:MODE
Description:
Turns on/off the user message display mode enabling the user to place text messages on the front
panel display.
Syntax:
DISPlay:LABel:MODE <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
Remote Operation
5-15
Boonton 4240 Series RF Power Meter
DISPlay:LABel:TEXTA
Description:
Displays a text message of up to 20 characters in the first label field when Display Label Mode is
enabled.
Syntax:
DISPlay:LABel:TEXTA <alphanumeric value>
Argument:
<alphanumeric value> = A to Z, a to z, 0 to 9, ! @ # $ % ^ & * ( ) _ - + = { } [ ] ? / < > : .
DISPlay:LABel:TEXTB
Description:
Displays a text message of up to 20 characters in the second label field when Display Label Mode
is enabled.
Syntax:
DISPlay:LABel:TEXTB <alphanumeric value>
Argument:
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & * ( ) _ - + = { } [ ] ? / < > : .
DISPlay:LABel:TEXTC
Description:
Displays a text message of up to 20 characters in the third label field when Display Label Mode is
enabled.
Syntax:
DISPlay:LABel:TEXTC <alphanumeric value>
Argument:
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & * ( ) _ - + = { } [ ] ? / < > : .
DISPlay:LABel:TEXTD
Description:
Displays a text message of up to 20 characters in the fourth label field when Display Label Mode
is enabled.
Syntax:
DISPlay:LABel:TEXTD <alphanumeric value>
Argument:
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & * ( ) _ - + = { } [ ] ? / < > : .
5-16
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.5 FETCh Queries
The FETCh? group of queries is used to return specific measurement data from a measurement cycle that has been INITiated
and is complete or free-running. FETCh? performs the data output portion of the measurement. FETCh? does not start a
new measurement, so a series of FETCh? queries may be used to return more than one set of processed measurements from a
complete set of acquired data. FETCh? usually returns the current value of measurements, and should be used anytime free
running data acquisition is taking place (INITiate:CONTinuous ON). If FETCh? is used for single measurements
(INITiate:CONTinuous OFF), no data will be returned until a measurement has been INITiated and is complete.
FETCh:CW:POWer?
Description:
Return current average amplitude reading in channel units.
Syntax:
FETCh[1|2]:CW:POWer?
Returns:
CC, average power
Where CC is the measurement condition code.
FETCh:KEY?
Description:
Return the key code of the last key depressed; e.g. MENU = 1.
Syntax:
FETCh:KEY?
Returns:
key code
Key
Code
Menu
1
Sensor
2
FREQ
4
AVG
8
Zero/Cal
16
REF Level
32
Up Arrow
64
Left Arrow
128
Enter
256
Right Arrow
512
Down Arrow
1024
Remote Operation
5-17
Boonton 4240 Series RF Power Meter
5.5.6 INITiate and ABORt Commands
The purpose of the INITiate group of commands is to start and control the process of data acquisition once a measurement
has been configured. Depending on settings, the 4240 RF Power Meter may be commanded to begin either a single
measurement (INITiate:CONTinuous OFF) which stops when complete, or enter a “free-run” mode where data acquisition
occurs continuously (INITiate:CONTinuous ON). The ABORt command terminates any operation in progress and prepares
the instrument for an INITiate command.
ABORt
Description:
Terminates any measurement in progress and resets the state of the trigger system. Note that
ABORt will leave the measurement in a stopped condition with all current measurements cleared,
and forces INITiate:CONTinuous to OFF.
Syntax:
ABORt
Argument:
None
INITiate:CONTinuous
Description:
Set or return the data acquisition mode for single or free-run measurements.
If
INITiate:CONTinuous is set to ON, the 4240 immediately begins taking measurements. If set to
OFF, the measurement will begin as soon as the INITiate command is issued, and will stop once
the measurement criteria (averaging, filtering or sample count) has been satisfied. Note that
INITiate:IMMediate and READ commands are invalid when INITiate:CONTinuous is set to
ON; however, by convention this situation does not result in a SCPI error.
Syntax:
INITiate:CONTinuous <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
INITiate[:IMMediate[:ALL]]
Description:
Starts a single measurement cycle when INITiate:CONTinuous is set to OFF. The measurement
will complete once the power has been integrated for the full FILTer time. No reading will be
returned until the measurement is complete. This command is not valid when
INITiate:CONTinuous is ON, however, by convention this situation does not result in a SCPI
error.
Syntax:
INITiate[:IMMediate[:ALL]]
Argument:
None
Restrictions:
INITiate:CONTinuous must be OFF
5-18
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.7 MEASure Queries
The MEASure group of commands is used to acquire data using a set of high level instructions. They are structured to allow
the user to trade off fine control of the measurement process for easy operability. MEASure? provides a complete capability
where the power meter is configured, a measurement taken, and results returned in one operation. The instrument is set to a
basic, predefined measurement state with little user intervention necessary or possible. Sometimes, more precise control of
measurement is required. In these cases, MEASure? should not be used. Rather, a sequence of configuration commands,
generally from the CALCulate and SENSe groups should be used to set up the instrument for the measurement, then READ?
or FETCH? commands are used to return the desired measurement data in a specific format.
MEASure:POWer?
Description:
Return a power measurement in dBm using a default instrument configuration. The instrument
remains stopped after a measurement.
Syntax:
Measure[1|2]:POWer?
Returns:
CC, Power in dBm
Where CC is the measurement condition code.
MEASure:VOLTage?
Description:
Return average voltage using a default instrument configuration in volts units. Instrument remains
stopped after a measurement.
Syntax:
MEASure[1|2]:VOLTage?
Returns:
CC, Average voltage in linear volts
Where CC is the measurement condition code.
Remote Operation
5-19
Boonton 4240 Series RF Power Meter
5.5.8 MEMory Subsystem
The MEMory group of commands is used to save and recall instrument operating configurations, and to edit and review usersupplied frequency dependent offset (FDOF) tables for external devices in the signal path. Up to ten configurations may be
saved, and two frequency dependent offset tables. Note, however that assigning a stored FDOF table to a particular
measurement channel is not a MEMory command; it is handled through the SENSe subsystem.
MEMory:SNSR:CF?
Description:
Return the sensor frequency cal-factor table.
Syntax:
MEMory:SNSR[1|2]:CF?
Argument:
None, query only.
MEMory:SNSR:CWRG?
Description:
Return sensor AC cal data.
Syntax:
MEMory:SNSR[1|2]:CWRG?
Argument:
None, query only.
MEMory:SNSR:INFO?
Description:
Return the sensor ID and parameter data.
Syntax:
MEMory:SNSR[1|2]:INFO?
Argument:
None
MEMory:SYS:LOAD
Description:
Recall a previously stored configuration of an instrument setup.
Syntax:
MEMory:SYS:LOAD <filename>
Argument:
Alphanumeric filename, "USER0" thru "USER10"
MEMory:SYS:STORe
Description:
Save the configuration of the current instrument setup.
Syntax:
MEMory:SYS:STORe <filename>
Argument:
Alphanumeric filename, "USER1" thru "USER10"
5-20
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.9 OUTPut Subsystem
The OUTPut group of commands is used to control various outputs of the 4240. These outputs include the internal 50 MHz
calibrator and the Recorder Output. The internal 50 MHz calibrator is primarily used for automatic calibration of power
sensors. Precise level continuous wave (CW) signals can also be sourced by the internal calibrator. OUTPut commands for
the Recorder Output include setting the DC output to the MAXimum or MINimum level or can be forced to any level in
between. Also the Recorder Output can be assigned to either channel 1 or 2.
OUTPut:LEVel[:POWer]
Description:
Set or return the power level of the internal 50 MHz calibrator output signal.
Syntax:
OUTPut:LEVel[:POWer ]< numeric value >
Argument:
< numeric value > = -60.0 to +20.0 dBm (0.1dB resolution)
OUTPut:SIGNal
Description:
Set or return the on/off state of the internal 50 MHz output signal.
Syntax:
OUTPut:SIGNal <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
OUTPut:RECorder:FORCe
Description:
Command sets the output voltage to the argument. Query returns the output voltage previously set
by FORCe or causes error -221 “Settings conflict” if the Recorder Ouput has been assigned to a
channel.
Syntax:
OUTPut:RECorder:FORCe <numeric value>
Argument:
<numeric value> = 0.000 to + 10.000 V
OUTPut:RECorder:MAX
Description:
Set or return the recorder output maximum, or full scale (+10.0V) power reference level.
Syntax:
OUTPut:RECorder:MAX
Argument:
none
OUTPut:RECorder:MIN
Description:
Set or return the recorder output minimum, or downscale (0.0V) power reference level.
Syntax:
OUTPut:RECorder:MIN
Argument:
none
Remote Operation
5-21
Boonton 4240 Series RF Power Meter
OUTPut:RECorder:SOURce
Description:
Set or return the source channel for the Recorder Output.
Syntax:
OUTPut:RECorder:SOURce <character data>
Argument:
<character data> = CH1, CH2, ACTIVE
5-22
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.10 READ Queries
The purpose of the READ? group of queries is to initiate a measurement cycle, acquire data, and return specific measurement
data. READ? performs the initiation, data acquisition, postprocessing, and data output portions of the measurement. READ?
is equivalent to ABORting any operation in progress, INITiating a new measurement, then FETChing the data when it is
ready. READ? generally does not return data unless acquisition is complete. Since READ? INITiates a new measurement
every time it is issued, READ? queries should not be used for free running data acquisition (INITiate:CONTinuous ON) - in
this case, use FETCh queries instead. The measurement is generally considered complete when the integration filter (see
SENSe:FILTer) is filled.
READ:CW:POWer?
Description:
Return current average amplitude reading in channel units.
Syntax:
READ[1|2]:CW:POWer?
Returns:
CC, Average power (watts, dBm)
Where CC is the measurement condition code.
Remote Operation
5-23
Boonton 4240 Series RF Power Meter
5.5.11 SENSe Subsystem
The purpose of the SENSe command subsystem is to directly configure device specific settings used to make measurements,
generally parameters related to the RF power sensor and signal processing. The SENSe commands are used to configure the
power meter for acquiring data. SENSe enables you to change measurement parameters such as filtering or averaging,
operating frequency and calfactors, and measurement gain or offset. The numeric suffix of the SENSe program mnemonic in
the SENSe commands refers to a hardware measurement “channel”, that is SENSe1 and SENSe2 represent the instrument’s
SENSOR 1 and SENSOR 2 signal paths, respectively. The SENSe commands generally DO NOT affect the data processing
and display portion of the measurement (see the CALCulate subsystem, Section 5.5.2). Note that SENSe2 commands will
generate an error if used with a single channel 4240 Series instrument.
SENSe:CORRection:CALFactor
Description:
Set or return the frequency calfactor currently in use on the selected channel. Note setting a
calfactor with this command will override the “automatic” frequency calfactor that was calculated
and applied when the operating frequency was set, and setting the operating frequency will
override this calfactor setting.
Syntax:
SENSe[1|2]:CORRection:CALFactor <numeric value>
Argument:
<numeric value> = –3.00 to 3.00 dB
SENSe:CORRection:DCYCle
Description:
Set or return the duty cycle correction factor currently in use on the selected channel.
Syntax:
SENSe[1|2]:CORRection:DCYCle
Argument:
<numeric value> = 0.01 to 100.00 percent
SENSe:CORRection:FREQuency
Description:
Set or return the RF frequency for the current sensor, and apply the appropriate frequency
calfactor from the sensor’s EEPROM table. Application of this calfactor cancels out the effect of
variations in the flatness of the sensor’s frequency response. If an explicit calfactor has been set,
either manually or via the SENSe:CORRection:CALFactor command, entering a new frequency
will override this calfactor and use only the “automatic” frequency calfactor.
Syntax:
SENSe[1|2]:CORRection:FREQuency <numeric value>
Argument:
<numeric value> = 0.01e9 to 110.0e9 Hz (actual sensor may have narrower range)
SENSe:CORRection:OFFSet
Description:
Set or return a measurement offset in dB for the selected sensor. This is used to compensate for
external couplers, attenuators or amplifiers in the RF signal path ahead of the power sensor.
Syntax:
SENSe[1|2]:CORRection:OFFSet <numeric value>
Argument:
<numeric value> = -99.99 to 99.99 dB
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Remote Operation
Boonton 4240 Series RF Power Meter
SENSe:FILTer:STATe
Description:
Set or return the current setting of the integration filter on the selected channel. OFF provides no
filtering, and can be used at high signal levels when absolute minimum settling time is required.
ON allows a user-specified integration time, from 50 milliseconds to 20 seconds (see
SENSe:FILTer:TIMe command). Note that setting the filter time will force the state to ON.
AUTO uses a variable amount of filtering, which is set automatically by the power meter based on
the current signal level to a value that gives a good compromise between measurement noise and
settling time at most levels.
Syntax:
SENSe[1|2]:FILTer:STATe <character data>
Argument:
<character data> = {OFF, ON, AUTO}
SENSe:FILTer:TIMe
Description:
Set or return the current length of the integration filter on the selected channel. If the filter state is
set to AUTO, querying the time will return -0.01, and if set to OFF, a time query will return 0.00.
Note that setting the filter time will force the state to ON.
Syntax:
SENSe[1|2]:FILTer:TIMe <numeric value>
Argument:
<numeric value> = 0.05 to 20.00 seconds in 50 millisecond increments
Remote Operation
5-25
Boonton 4240 Series RF Power Meter
5.5.12 STATus Commands
The STATus command subsystem enables you to control the SCPI defined status reporting structures. The user may
examine the status or control status reporting of the power meter by accessing the Device, Operation and Questionable status
groups.
STATus:DEVice:CONDition?
Description:
Return the current value of the Device Condition register. The following table shows the bit
assignments in the register. These bits are updated by the instrument in real time, and can change
in response to changes in the instrument’s operating condition.
Bit
Value
Definition
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
Not used
Channel 1 Connected
Channel 2 Connected
Channel 1 Error
Channel 2 Error
Shape Cal 1
Shape Cal 2
Smart Cal 1
Smart Cal 2
Auto Cal 1
Auto Cal 2
Not used
Not used
Key Press
Not used
Not used
Syntax:
STATus:DEVice:CONDition?
Returns:
16-bit register value (0 to 65535)
always returns 0.
1 = A sensor or probe is connected to channel 1.
1 = A sensor or probe is connected to channel 2.
1 = Channel 1 is reporting an error.
1 = Channel 2 is reporting an error.
1 = Channel 1 is using a CW shape cal table.
1 = Channel 2 is using a CW shape cal table.
1 = Channel 1 is using a CW smart cal table.
1 = Channel 2 is using a CW smart cal table.
1 = Channel 1 is using an auto cal table.
1 = Channel 2 is using an auto cal table.
always returns 0.
always returns 0.
1 = A key has been pressed.
always returns 0.
always returns 0.
STATus:DEVice:ENABle
Description:
Sets or returns the Device Enable register, which contains the bit mask that defines which true
conditions in the Device Status Event register will be reported in the Device Summary bit of the
instrument Status Byte. If any bit is 1 in the Device Enable register and its corresponding Device
Event bit is true, the Device Status summary bit will be set.
Syntax:
STATus:DEVice:ENABle <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
5-26
Remote Operation
Boonton 4240 Series RF Power Meter
STATus:DEVice:EVENt?
Description:
Returns the current contents of the Device Event register then resets the register value to 0. The
Device Event register contains the latched events from the Device Condition register as specified
by the Device status group’s positive and negative transition filters.
Syntax:
STATus:DEVice:EVENt?
Returns:
16-bit register value (0 to 65535)
STATus:DEVice:NTRansition
Description:
Set or return the value of the negative transition filter bitmask for the Device status group. Setting
a bit in the negative transition filter causes a 1 to 0 (negative) transition in the corresponding bit of
the Device Condition register to cause a 1 to be written in the associated bit of the Device Event
register.
Syntax:
STATus:DEVice:NTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:DEVice:PTRansition
Description:
Set or return the value of the positive transition filter bitmask for the Device status group. Setting
a bit in the positive transition filter causes a 0 to 1 (positive) transition in the corresponding bit of
the Device Condition register to cause a 1 to be written in the associated bit of the Device Event
register.
Syntax:
STATus:DEVice:PTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
Remote Operation
5-27
Boonton 4240 Series RF Power Meter
STATus:OPERation:CONDition?
Description:
Return the current value of the Operation Condition register. The following table shows the bit
assignments in the register. These bits are updated by the instrument in real time, and can change
in response to changes in the instrument’s operating condition.
Bit
Value
Definition
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
Calibrating
Settling
Ranging
Not used
Measuring
Triggering
Not used
Not used
Alarm 1
Alarm 2
Alarm Latch 1
Alarm Latch 2
Not used
Not used
Not used
Not used
1 = sensor calibration in progress.
1 = averaging filter is not full.
1 = range change in progress.
always returns 0.
1 = measurement in progress.
1 = Trigger mode enabled waiting for a trigger.
always returns 0.
always returns 0.
1 = Channel 1 is in an alarm condition.
1 = Channel 2 is in an alarm condition.
1 = Channel 1 alarm is latched.
1 = Channel 2 alarm is latched.
always returns 0
always returns 0.
always returns 0.
always returns 0.
Syntax:
STATus:OPERation:CONDition?
Returns:
16-bit register value (0 to 65535)
STATus:OPERation:ENABle
Description:
Sets or returns the Operation Enable register, which contains the bit mask that defines which true
conditions in the Operation Status Event register will be reported in the Operation Summary bit of
the instrument Status Byte. If any bit is 1 in the Operation Enable register and its corresponding
Operation Event bit is true, the Operation Status summary bit will be set.
Syntax:
STATus:OPERation:ENABle <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:OPERation:EVENt?
Description:
Returns the current contents of the Operation Event register then resets the register value to 0. The
Operation Event register contains the latched events from the Operation Condition register as
specified by the Operation status group’s positive and negative transition filters.
Syntax:
STATus:OPERation:EVENt?
Returns:
16-bit register value (0 to 65535)
5-28
Remote Operation
Boonton 4240 Series RF Power Meter
STATus:OPERation:NTRansition
Description:
Set or return the value of the negative transition filter bitmask for the Operation status group.
Setting a bit in the negative transition filter causes a 1 to 0 (negative) transition in the
corresponding bit of the Operation Condition register to cause a 1 to be written in the associated
bit of the Operation Event register.
Syntax:
STATus:OPERation:NTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:OPERation:PTRansition
Description:
Set or return the value of the positive transition filter bitmask for the Operation status group.
Setting a bit in the positive transition filter causes a 0 to 1 (positive) transition in the
corresponding bit of the Operation Condition register to cause a 1 to be written in the associated
bit of the Operation Event register.
Syntax:
STATus:OPERation:PTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:PRESet
Description:
Sets SCPI enable registers and transition filters to the default state. The Operational Enable and
Questionable Enable mask registers are both cleared so an SRQ will not be generated for these
conditions. All bits for the device and questionable calibration registers are enabled. All positive
transition filters are enabled and all negative transition filters are cleared.
Syntax:
STATus:PRESet
Argument:
None
Remote Operation
5-29
Boonton 4240 Series RF Power Meter
STATus:QUEStionable:CONDition?
Description:
Return the current value of the Questionable Condition register. The following table shows the
bit assignments in the register. These bits are updated by the instrument in real time, and can
change in response to changes in the instrument’s operating condition.
Bit
Value
Definition
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768
Not used
Not used
Not used
Power
Not used
Not used
Not used
Not used
Calibration
Not used
Not used
Not used
Not used
Not used
Not used
Not used
always 0.
always 0.
always 0.
1 = a power measurement may be invalid.
always 0.
always 0.
always 0.
always 0.
1 = sensor requires calibration and/or zeroing
always 0.
always 0.
always 0.
always 0.
always 0.
always 0.
always 0.
Syntax:
STATus:QUEStionable:CONDition?
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:ENABle
Description:
Sets or returns the Questionable Enable register, which contains the bit mask that defines which
true conditions in the Questionable Status Event register will be reported in the Questionable
Summary bit of the instrument Status Byte. If any bit is 1 in the Questionable Enable register and
its corresponding Questionable Event bit is true, the Questionable Status summary bit will be set.
Syntax:
STATus:QUEStionable:ENABle <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:EVENt?
Description:
Returns the current contents of the Questionable Event register then resets the register value to 0.
The Questionable Event register contains the latched events from the Questionable Condition
register as specified by the Questionable status group’s positive and negative transition filters.
Syntax:
STATus:QUEStionable:EVENt?
Returns:
16-bit register value (0 to 65535)
5-30
Remote Operation
Boonton 4240 Series RF Power Meter
STATus:QUEStionable:NTRansition
Description:
Set or return the value of the negative transition filter bit mask for the Questionable status group.
Setting a bit in the negative transition filter causes a 1 to 0 (negative) transition in the
corresponding bit of the Questionable Condition register to cause a 1 to be written in the
associated bit of the Questionable Event register.
Syntax:
STATus:QUEStionable:NTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:PTRansition
Description:
Set or return the value of the positive transition filter bit mask for the Questionable status group.
Setting a bit in the positive transition filter causes a 0 to 1 (positive) transition in the
corresponding bit of the Questionable Condition register to cause a 1 to be written in the
associated bit of the Questionable Event register.
Syntax:
STATus:QUEStionable:PTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:CALibration:CONDition?
Description:
Return the current value of the Questionable Calibration Condition register. This register is used
to notify the user of questionable quality with respect to calibration. The following table shows
the bit assignments in the register. These bits are updated by the instrument in real time, and can
change in response to changes in the instrument’s operating condition.
Bit
Value
0
1
2
3
1
2
4
8
Definition
Not Used
Not used
Sens1 Default Shape
Sens2 Default Shape
1 = Channel 1 using default shape table.
1 = Channel 2 using default shape table.
Syntax:
STATus:QUEStionable:CALibration:CONDition?
Returns:
16-bit register value (0 to 65535)
Remote Operation
5-31
Boonton 4240 Series RF Power Meter
STATus:QUEStionable:CALibration:ENABle
Description:
Sets or returns the Questionable Calibration Enable register, which contains the bit mask that
defines which true conditions in the Questionable Calibration Event register will be reported in the
Questionable Calibration Summary bit of the Questionable Condition register. If any bit is 1 in
the Questionable Calibration Enable register and its corresponding Questionable Calibration Event
bit is true, the Questionable Calibration summary bit will be set.
Syntax:
STATus:QUEStionable:CALibration:ENABle <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:CALibration:EVENt?
Description:
Returns the current contents of the Questionable Calibration Event register then resets the register
value to 0. The Questionable Calibration Event register contains the latched events from the
Questionable Calibration Condition register as specified by the Questionable Calibration status
group’s positive and negative transition filters.
Syntax:
STATus:QUEStionable:CALibration:EVENt?
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:CALibration:NTRansition
Description:
Set or return the value of the negative transition filter bit mask for the Questionable Calibration
status group. Setting a bit in the negative transition filter causes a 1 to 0 (negative) transition in the
corresponding bit of the Questionable Calibration Condition register to cause a 1 to be written in
the associated bit of the Questionable Calibration Event register.
Syntax:
STATus:QUEStionable:CALibration:NTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
STATus:QUEStionable:CALibration:PTRansition
Description:
Set or return the value of the positive transition filter bit mask for the Questionable Calibration
status group. Setting a bit in the positive transition filter causes a 0 to 1 (positive) transition in the
corresponding bit of the Questionable Calibration Condition register to cause a 1 to be written in
the associated bit of the Questionable Calibration Event register.
Syntax:
STATus:QUEStionable:CALibration:PTRansition <numeric value>
Argument:
<numeric value> = 0 to 65535
Returns:
16-bit register value (0 to 65535)
5-32
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.13 SYSTem Subsystem
The SYSTem group of commands is used to control system-level functions not directly related to instrument measurement
performance. SYSTem commands are used to return error codes or messages from the power meter error queue, control
hardware features and configure communication parameters for the GPIB.
SYSTem:BEEP[:ENABle]
Description:
Set or return the status of the audible keyboard beeper.
Syntax:
SYSTem:BEEP[:ENABle] <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
SYSTem:BEEP:IMMediate
Description:
Causes the system to emit an audible beep. Command only; does not respond to a query.
Syntax:
SYSTem:BEEP:IMMediate
Argument:
None
SYSTem:COMMunicate:GPIB:ADDRess
Description:
Set or return the GPIB bus address.
Syntax:
SYSTem:COMMunicate:GPIB:ADDRess <numeric value>
Argument:
<numeric value> = 1 to 30
SYSTem:COMMunicate:GPIB:EOI
Description:
Set or return the status of the GPIB EOI .
Syntax:
SYSTem:COMMunicate:GPIB:EOI <Boolean>
Argument:
<Boolean> = { 0, 1, OFF, ON }
SYSTem:COMMunicate:GPIB:LISTen
Description:
Set or return the GPIB Listen end-of-string terminator .
Syntax:
SYSTem:COMMunicate:GPIB:LISTen <character data>
Argument:
<character data> = {LF, CR, CRLF, EOIONLY}
Remote Operation
5-33
Boonton 4240 Series RF Power Meter
SYSTem:COMMunicate:GPIB:TALK
Description:
Set or return the GPIB Talk end-of-string terminator .
Syntax:
SYSTem:COMMunicate:GPIB:TALK <character data>
Argument:
<character data> = {LF, CR, CRLF, EOIONLY}
SYSTem:COMMunicate:SERial:BAUD
Description:
Set or return the RS232 baud rate.
Syntax:
SYSTem:COMMunicate:SERial:BAUD <numeric value>
Argument:
<numeric value> = 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
SYSTem:COMMunicate:SERial:BITS
Description:
Set or return the RS232 serial word length (Data Bits).
Syntax:
SYSTem:COMMunicate:SERial:BITS <numeric value>
Argument:
<numeric value> = 7, 8
SYSTem:COMMunicate:SERial:PARity
Description:
Set or return the RS232 parity.
Syntax:
SYSTem:COMMunicate:SERial:PARity < character data >
Argument:
<character data> = ODD, EVEN, NONE
SYSTem:COMMunicate:SERial:SBITs
Description:
Set or return the number of RS232 serial stop bits.
Syntax:
SYSTem:COMMunicate:SERial:SBITs <numeric value>
Argument:
<numeric value> = 1, 2
5-34
Remote Operation
Boonton 4240 Series RF Power Meter
SYSTem:ERRor[:NEXT]?
Description:
Returns the next queued error code number followed by a quoted ASCII text string describing the
error. Note that errors are stored in a “first-in-first-out” queue, so if more than one error has
occurred, repeating this command will report the errors in the sequence they happened. The action
of reading an error removes that error from the queue, so once the most recent error has been read,
further queries will report a code of zero, and “No Error”. See Appendix A for detailed
descriptions of the error codes that may be returned.
Syntax:
SYSTem:ERRor[:NEXT]?
Returns:
<numeric error code>, “QUOTED ERROR DESCRIPTION”
SYSTem:ERRor:CODE?
Description:
Returns the next queued error code number. Note that errors are stored in a “first-in-first-out”
queue, so if more than one error has occurred, repeating this command will report the error codes
in the sequence they happened. The action of reading an error removes that error from the queue,
so once the most recent error has been read, any more queries will report a code of zero. See
Appendix A for a more detailed description of the error codes that may be returned.
Syntax:
SYSTem:ERRor:CODE?
Returns:
<numeric error code>
SYSTem:ERRor:COUNt?
Description:
Returns the number of errors that currently exist in the error queue. A value of 0 means that there
are no errors in the queue. Therefore, either no errors have occurred, or all errors have been read.
See Appendix A for a more detailed description of the error codes that may be returned.
Syntax:
SYSTem:ERRor:COUNt?
Returns:
<numeric error code>
SYSTem:PRESet
Description:
Set 4240 default parameters. Equivalent to SETUP > RECALL > DEFAULT. See Tables 3-2, 3-3
and 3-4 for a list of the default values for each parameter.
Syntax:
SYSTem:PRESet
Argument:
None
SYSTem:VERSion?
Description:
Return the SCPI version compliance claimed.
Syntax:
SYSTem:VERSion?
Returns:
<character data> = Version Code as <year.version> YYYY.V (will return 1999.0)
Remote Operation
5-35
Boonton 4240 Series RF Power Meter
5.5.14 INSTrument:VERSion Commands
INSTrument:VERSion group of commands is used to query the firmware and FPGA revision codes. The firmware code
follows a “YYYYMMDD” format. The FPGA revision format has a major and minor representation in the form of
“MM.mm” where “MM” is the major revision number and “mm” in the minor revision number.
INSTrument:VERSion:FIRMware?
Description:
Returns the firmware revision code.
Syntax:
INSTrument:VERSion:FIRMware?
Returns:
YYYYMMDD
INSTrument:VERSion:FPGA?
Description:
Returns the FPGA revision code.
Syntax:
INSTrument:VERSion:FPGA?
Returns:
MM.mm
5-36
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.15 SCPI Command Summary
Table 5-1. SCPI COMMAND SUMMARY
*CLS
Clear Status Command
*ESE
Set/get Standard Event Status Enable
*ESR?
Standard Event Status Register Query
*IDN
Identification Query
*OPC
Operation Complete Command
*OPC?
Operation Complete Query
*OPT?
Return the instrument options
*RST
Reset Command
*SRE
Set/get Service Request Enable
*STB?
Read Status Byte Query
*TRG
Simulate Group Execute Trigger
*TST?
Self-Test Query
ABORt
Immediately set measurement trigger system to idle
CALCulate[1|2]:LIMit:CLEar[:IMMediate]
Clear all latched limit alarms
CALculate[1|2]:LIMit:FAIL?
Return the status of all alarms.
<Boolean> = {summary, LL, UL, LLL, ULL}
CALCulate[1|2]:LIMit:LOWer[:POWer]
Set/return lower limit power level.
< numeric value > = -99.99 to +99.99 dBm
CALCulate[1|2]:LIMit[:BOTH]:STATe
Set or return the combined upper and lower limit alarm system
state for the selected channel.
CALCulate[1|2]:LIMit:LOWer:STATe
Set/return lower limit alarms. <Boolean> = 0, 1, OFF, ON
CALCulate[1|2]:LIMit:UPPer:STATe
Set/return upper limit alarms. <Boolean> = 0, 1, OFF, ON
CALCulate[1|2]:LIMit:UPPer[:POWer]
Set/return upper limit power level.
< numeric value > = -99.99 to +99.99 dBm
CALCulate:MATH:ARGA
Set or return the first argument to be used for channel math
operations.
Remote Operation
5-37
Boonton 4240 Series RF Power Meter
Table 5-1. SCPI COMMAND SUMMARY (continued)
CALCulate:MATH:ARGB
Set or return the second argument to be used for channel math
operations.
CALCulate:MATH:DATA?
Returns the channel math result.
CALCulate:MATH:OPERator
Set or return the channel math operator.
CALCulate:MODE
Set/return remote measurement mode
<character data> = NORMal, FAST, FILTered
CALCulate[1|2]:REFerence:COLLect
Set the current reading to be the ratiometric measurement reference
level.
CALCulate[1|2]:REFerence:DATA
Set or return the ratiometric measurement reference level in dBm.
<numeric value> = -99.99 to +99.99 dBm
CALCulate[1|2]:REFerence:STATe
Set or return the ratiometric measurement mode state.
<Boolean> = 0, 1, OFF, ON
CALCulate[1|2]:STATe
Enable currently selected channel allowing measurements to be
made.
<Boolean> = 0, 1, OFF, ON
CALCulate[1|2]:UNITs
Change channel units. <character value> = DBM, Watts, Volts,
DBV, DBMV, DBUV
CALibration[1|2]:AUTOcal
Start auto calibration with internal calibrator.
CALibration[1|2]:FIXedcal
Start fixed calibration with internal calibrator.
CALibration[1|2]:ZERO
Start zero process.
DISPlay:ACTive
Set/return the active channel for talk commands.
DISPlay:CLEar
Clear measurement data and display.
DISPlay:LIN:RESolution
Set number of significant digits for linear displays and remote
return values. <numeric value> = 3 to 5
DISPlay:LOG:RESolution
Set number of decimal places for log displays and remote return
values. <numeric value> = 1 to 3
DISPlay:LABel:MODE
Enables/disables the user message display.
<Boolean> = 0, 1, OFF, ON
DISPlay:Label:TEXTA
Displays a text message in the first label field.
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & *
()_-+={}[]?/<>:.
DISPlay:Label:TEXTB
Displays a text message in the second label field.
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & *
()_-+={}[]?/<>:.
5-38
Remote Operation
Boonton 4240 Series RF Power Meter
Table 5-1. SCPI COMMAND SUMMARY (continued)
DISPlay:Label:TEXTC
Displays a text message in the third label field.
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & *
()_-+={}[]?/<>:.
DISPlay:Label:TEXTD
Displays a text message in the fourth label field.
<alphanumeric value> = A to Z, a to z, 0 to 9 ! @ # $ % ^ & *
()_-+={}[]?/<>:.
FETCh[1|2]:CW:POWer?
Return current average reading in power units
FETCh:KEY?
Return code of last key depressed
INITiate:CONTinuous
Set/return state of mode which triggers meas cycles continuously.
<Boolean> = 0, 1, OFF, ON
INITiate[:IMMediate[:ALL]]
Set mode which starts a measurement cycle when trigger event
occurs
MEASure[1|2]:POWer?
Return the average power measurement in dBm
MEASure[1|2]:VOLTage?
Return the average power measurement in equivalent volts.
MEMory[1|2]:SNSR:CF?
Return the sensor frequency cal-factor table.
MEMory[1|2]:SNSR:CWRG?
Return sensor AC cal data.
MEMory[1|2]:SNSR:INFO?
Return the sensor ID and parameter data.
MEMory:SYST:LOAD
Load saved instrument setup by filename.
<character data> = "USER0" ... "USER10".
MEMory:SYST:STORe
Save instrument setup by filename.
<character data> = "USER1" ... "USER10".
OUTPut:LEVel[:POWer]
Set or return the power level of the internal 50 MHz calibrator
output signal.
OUTPut:SIGNal
Set or return the on/off state of the internal 50 MHz output signal.
OUTPut:RECorder:FORCe
Command sets the Recorder Output voltage to the argument.
<numeric value> = 0.0 to + 10.0 V
OUTPut:RECorder:MAX
Set or return the Recorder Output maximum, or full scale (+10.0V)
power reference level.
OUTPut:RECorder:MIN
Set or return the Recorder Output minimum, or downscale (0.0V)
power reference level
OUTPut:RECorder:SOURce
Set or return the source channel for the Recorder Output.
<character data> = CH1, CH2, ACTIVE
READ[1|2]:CW:POWer?
Return new average reading in power units.
Remote Operation
5-39
Boonton 4240 Series RF Power Meter
5-1. SCPI COMMAND SUMMARY (continued)
SENSe[1|2]:CORRection:CALFactor
Set correction factor in dB.
<numeric value> = -3.00 to 3.00
SENSe[1|2]:CORRection:DCYCle
Set/return duty cycle correction factor in percent.
<numeric value> = 0.0 to 100.0%
SENSe[1|2]:CORRection:FREQuency
Set channel frequency.
<numeric value> = 0.01e9 to 110.00e9 Hz
SENSe[1|2]:CORRection:OFFSet
Set/return sensor offset value in dB.
<numeric value> = -99.99 to 99.99
SENSe[1|2]:FILTer:STATe
Set/return filter state.
<character data> = OFF, AUTO, ON
SENSe[1|2]:FILTer:TIMe
Set or return the current length of the integration filter on the
selected channel. <numeric value> = 0.05 to 20.00 seconds
STATus:DEVice:CONDition?
Return value of Device Condition Register
STATus:DEVice:ENABle
Set/return value of Device Enable Mask
STATus:DEVice:EVENt?
Return value of Device Event Register
STATus:DEVice:NTRansition
Set/return the Negative Transition filter
STATus:DEVice:PTRansition
Set/return the Positive Transition filter
STATus:OPERation:CONDition?
Return value of Operation Condition Register
STATus:OPERation:ENABle
Set/return value of Operation Enable Mask
STATus:OPERation:EVENt?
Return value of Operation Event Register
STATus:OPERation:NTRansition
Set/return the Negative Transition filter
STATus:OPERation:PTRansition
Set/return the Positive Transition filter
STATus:PRESet
Set device dependent SCPI registers to default states
STATus:QUEStionable:CONDition?
Return value of Questionable Condition Register
STATus:QUEStionable:ENABle
Set/return value of Questionable Enable Mask
STATus:QUEStionable:EVENt?
Return value of Questionable Event Register
STATus:QUEStionable:NTRansition
Set/return the negative transition filter
STATus:QUEStionable:PTRansition
Set/return the positive transition filter
STATus:QUEStionable:CALibration:CONDition?
Return value of the questionable calibration condition register
STATus:QUEStionable:CALibration:ENABle
Set/return value of the questionable calibration enable mask
5-40
Remote Operation
Boonton 4240 Series RF Power Meter
Table 5-1. SCPI COMMAND SUMMARY (continued)
STATus:QUEStionable:CALibration:EVENt?
Return value of the questionable calibration event register
STATus:QUEStionable:CALibration:NTRansition
Set/return the negative transition filter
STATus:QUEStionable:CALibration:PTRansition
Set/return the positive transition filter
SYSTem:BEEP[:ENABle]
Set/return keypad audible beeper status.
<Boolean> = 0, 1, OFF, ON
SYSTem:BEEP:IMMediate
Causes a beep to be emitted. No argument. No return.
SYSTem:COMMunicate:GPIB:ADDRess
Set or return the GPIB bus address.
<numeric value> = 1 to 30
SYSTem:COMMunicate:GPIB:EOI
Set/return the status of the GPIB EOI.
<Boolean> = 0, 1, OFF, ON
SYSTem:COMMunicate:GPIB:LISTen
Set/return the GPIB Listen end-of-string terminator.
<character data> = LF, CR, CRLF, EOIONLY
SYSTem:COMMunicate:GPIB:TALK
Set/return the GPIB Talk end-of-string terminator.
<character data> = LF, CR, CRLF, EOIONLY
SYSTem:COMMunicate:SERial:BAUD
Set/return the RS232 baud rate.
<numeric value> = 300, 600, 1200, 2400, 4800, 9600, 19200,
38400, 57600, 115200
SYSTem:COMMunicate:SERial:BITS
Set/return the RS232 serial Data Bits.
<numeric value> = 7,8
SYSTem:COMMunicate:SERial:PARity
Set/return the RS232 Parity.
<character data> = ODD, EVEN, NONE
SYSTem:COMMunicate:SERial:SBITS
Set/return the RS232 serial Stop Bits.
<numeric value> = 1,2
SYSTem:ERRor[:NEXT]?
Return system error code and description
SYSTem:ERRor:CODE?
Return system error code
SYSTem:ERRor:COUNt?
Return the number of errors in the queue
SYSTem:PRESet
Set instrument to default conditions.
SYSTem:VERSion?
Return SCPI version compliance.
<numeric value> = yyyy.v
INSTrument:VERSion:FIRMware?
Returns the firmware revision code.
<numeric value> = yyyymmdd
INSTrument:VERSion:FPGA?
Returns the FPGA revision code.
<numeric value> = MM.mm
Remote Operation
5-41
Boonton 4240 Series RF Power Meter
5.5.16 4230 Emulation GPIB Commands
Table 5-2. 4230 EMULATION GPIB COMMANDS
Code
Description
AM
Measure A-B
AP
Measure A + B
AR
Measure A/B
BD
Measure B - A
BR
Measure B/A
BN
4230A Native mode
CH
Channel select 1 - 2
CF
Calibrator off
CL
Clear
CN
Calibrator on
CP
Calibrate
DB
dBm select
DF
Display off
DN
Display on
DR
dBr select
DU
Display user message
DY
Duty cycle value
FA
Auto filter
FD
dB calibration factor
FI
Send high frequency calibration data to instrument
FL
Filter time select
FO
Get high frequency calibration data from instrument
FR
Frequency select
HPS
Enable HP 437B emulation mode
HPD
Enable HP 438A emulation mode
?ID
Talk instrument ID
*IDN?
Talk instrument ID 1
LH
High limit
-99.99 to 99.99 in 0.01 steps
LL
Low limit
-99.99 to 99.99 in 0.01 steps
LM0
Disable limits checking function
LM1
Enable limits checking function
LR
Load reference
5-42
Remote Operation
Comments
0.01 - 100.00 in 0.01 steps
-3.00 to 3.00 in 0.01 steps
0 to 20.00 in 0.05 steps
Boonton 4240 Series RF Power Meter
Table 5-2. 4230 EMULATION GPIB COMMANDS (continued)
Code
Description
Comments
MF
Measure filtered
MFD
Measure Fast Dual Channels
MFS
Measure fast single channel
MN
Measure normal, free run
MS
Measure settled
OS
Offset value
PW
Watts select
RA
Autorange
RB
Recorder bottom
RC
Recall instrument configuration
1 - 10
RE
Resolution
1-3
RN
Recorder normal
RS
Range select
RT
Recorder top
SCPI
Set remote programming language to SCPI
SI
Send linearity data to instrument
SM
Service request (SRQ) mask
SO
Get linearity data from instrument
SR
Set dBr reference
-99.99 to 99.99 in 0.01 steps
SS
Sensor select
1-6
ST
Store instrument configuration
1 - 10
TF
Trigger filtered
TFD
Trigger fast dual channels
TFS
Trigger fast single channel
TN
Trigger normal
TM
Talk mode
TR
Bus trigger
TS
Trigger settled
ZR
Instrument zero
-99.99 to 99.99 in 0.01 steps
0-6
0 - 255
0-6
1 The * must be included as part of the GPIB command string.
Remote Operation
5-43
Boonton 4240 Series RF Power Meter
5.5.17 HP 437B Emulation GPIB Commands
Table 5-3. HP 437B EMULATION GPIB COMMANDS
Code
Description
Comments
1
CL
0 dBm Calibration
*CLS
Clear the status register3
CS
Clear the status byte
CT0 - CT9
Clear sensor data tables 0 - 91
DA
All display segments on
DC0
Duty cycle on ('DY' ARG # 100)
NOT SUPPORTED
DC1
Duty cycle off ('DY' ARG = 100)
NOT SUPPORTED
DD, DF
Display disable
DE
Display enable
DN
Down arrow key
DU
Display user message
DY
Duty cycle value1
EN
ENTER
ERR?
Device error query
*ESE
Set event status enable mask3
*ESE?
Event status register query3
*
ESR?
Event status register (ESR) query3
ET0 - ET9
Edit sensor calibration factor table 0 - 91
EX
EXIT
FA
Automatic filter selection
FH
Filter hold
FM
Manual filter selection1
FR
Frequency entry1
GT0
Ignore group execute trigger (GET) bus command
GT1
Trigger immediate response to GET command
GT2
Trigger with delay response to GET command
GZ
Gigahertz
HZ
Hertz
ID
GPIB identification query
*IDN?
GPIB identification query2
KB
calibration factor1 in percent
5-44
Remote Operation
NOT SUPPORTED
NOT SUPPORTED
Boonton 4240 Series RF Power Meter
Table 5-3. HP 437B EMULATION GPIB COMMANDS
Code
Description
KZ
Kilohertz
LG
Log display
LH
High limit1
LL
Low limit1
LM0
Disable limits checking function
LM1
Enable limits checking function
LN
Linear display
LP
Learn Mode
LT
Left arrow key
MZ
Megahertz
OC0
Reference oscillator off
OC1
Reference oscillator on
OD
Output display text
Comments
NOT SUPPORTED
NOT SUPPORTED
Offset off
4
NOT SUPPORTED
OF1
Offset on
4
NOT SUPPORTED
OS
Offset value1
PCT
Percent
PR
Preset
RA
Autorange
RC
RECALL1
RE
Resolution1
OF0
1 - 10
1-3
1
RF0 - RF9
Enter sensor reference calibration factor
RH
Range hold
RL0
Exit REL mode
RL1
Enter REL mode using new REL value
RL2
Enter REL mode using old REF value
RM
Set range1
*RST
Soft reset3
RT
Right arrow key
RV
Read Service Request Mask value
SCPI
Set remote programming language to SCPI
SE
Sensor number1
Remote Operation
NOT SUPPORTED
1 - 6 only
5-45
Boonton 4240 Series RF Power Meter
Table 5-3. HP 437B EMULATION GPIB COMMANDS
Code
Description
SM
Status message
SN0 - SN9
Enter sensor serial number
SP - N0P
SPECIAL
Comments
NOT SUPPORTED
2
NOT SUPPORTED
NOT SUPPORTED
3
*SRE
Set the service request mask
*SRE?
Service request mask query3
ST
STORE1
*STB?
Read the status byte
TR0
Trigger hold
TR1
Trigger immediate
TR2
Trigger with delay
TR3
Trigger-free run
*TST?
Self test query3
UP
Up arrow key
ZE
ZERO
@1
Set the service request mask
@2
Learn mode prefix
%
Percent
1 - 10
NOT SUPPORTED
1 A numeric entry is required by these GPIB codes, followed by the code EN (ENTER).
2 This GPIB code uses the next 6 characters (0 - 9, A - Z, or an underscore) as input data.
3 The * must be included as part of the GPIB command string.
4 Offset value is always applied. Set the offset value to 0 dB for off condition. Any other value the offset is on.
5-46
Remote Operation
Boonton 4240 Series RF Power Meter
5.5.18 HP 438A Emulation GPIB Commands
Table 5-4. HP 438A EMULATION GPIB COMMANDS
Code
Description
AD
Measure A-B
AE
Set A
AP
Measure sensor A
AR
Measure A/B
BD
Measure B-A
BE
Set B
BP
Measure sensor B
BR
Measure B/A
CL
CAL ADJ1,2
CS
Clear status byte1
DA
Display all1
DD
Display disable1
DE
Display enable1
DO
Measured offset entry
EN
ENTER1
FA
Set auto average filtering
(precede with AE or BE)
FH
Hold present average number
(precede with AE or BE)
FM
Set filter number
Comments
1,2
(precede with AE or BE)
1
GT0
Group execute trigger cancel
GT1
Group execute trigger single measurement1
GT2
Group execute trigger full measurement with settling1
GZ
Gigahertz1
HZ
Hertz1
?ID
Ask of ID1
KB
Calibration factor1,2
KZ
Kilohertz1
LG
Set log units
LH
High limit1,2
LL
Low limit1,2
LM0
Disable limit checking1
LM1
Enable limit checking1
LN
Set linear units
Remote Operation
(dB or dBm) 1
(Watts or %)1
5-47
Boonton 4240 Series RF Power Meter
LP1
Set learn mode #1
NOT SUPPORTED
Table 5-4. HP 438A EMULATION GPIB COMMANDS
Code
Description
Comments
LP2
Set learn mode #2
NOT SUPPORTED
1
MZ
Megahertz
OC0
Turn off calibrator source1
OC1
Turn on calibrator source1
OS
Offset1,2
PR
Preset instrument to a known state1
RA
Resume autorange1
RC
RECALL1,2
RH
Range hold1
RL0
Relative mode off 1
RL1
Relative mode on1
RL2
Relative mode with old REL value1
RM
Set manual range 1,2
RV
Ask for status request mask1
SCPI
Set remote programming language to SCPI
SM
Ask for status message1
ST
STORE1,2
1 - 10
1 - 10
1
TR0
Trigger hold mode
TR1
Trigger single measurement1
TR2
Trigger full measurement with settling1
TR3
Free run trigger mode1
ZE
Zero sensor
@1
Prefix for service request mask1
(precede with AE or BE) 1
1 These commands are fully compatible with the HP437B Power Meter command codes.
2 Requires numeric entry followed by program code EN.
5-48
Remote Operation
Boonton 4240 Series RF Power Meter
6. Application Notes
This section provides supplementary material to enhance your knowledge of the 4240 Series' advanced features and
measurement accuracy. Topics covered in this section include pulse measurement fundamentals, automatic measurement
principles, and an analysis of measurement accuracy.
6.1 Pulse Measurements
6.1.1 Measurements Fundamentals
The following is a brief review of power measurement fundamentals.
Unmodulated Carrier Power. The average power of an unmodulated carrier consisting of a continuous, constant amplitude
sinewave signal is also termed CW power. For a known value of load impedance R, and applied voltage Vrms,
the average power is:
P = Vrms²/R
watts
Power meters designed to measure CW power can use thermoelectric detectors which respond to the heating effect of the
signal or diode detectors which respond to the voltage of the signal. With careful calibration accurate measurements can be
obtained over a wide range of input power levels.
Modulated Carrier Power. The average power of a modulated carrier which has varying amplitude can be measured
accurately by a CW type power meter with a thermoelectric detector, but the lack of sensitivity will limit the range. Diode
detectors can be used at low power, square-law response levels. At higher power levels the diode responds in a more linear
manner and significant error results.
Pulse Power. Pulse power refers to power measured during the on time of pulsed RF signals (Figure 6-1). Traditionally,
these signals have been measured in two steps: (1) thermoelectric sensors measure the average signal power, (2) the reading
is then divided by the duty cycle to obtain pulse power, Ppulse:
Ppulse = Average Power/ Duty Cycle
(measured)
where Duty Cycle = Pulse Width/Pulse Period
Pulse power provides useful results when applied to rectangular pulses, but is inaccurate for pulse shapes that include
distortions, such as overshoot or droop (Figure 6-2).
Application Notes
6-1
Boonton 4240 Series RF Power Meter
Figure 6-1.
Pulsed RF Signal
Figure 6-2.
Distorted Pulse Signal
6-2
Application Notes
Boonton 4240 Series RF Power Meter
6.1.2 Diode Detection
Wideband diode detectors are the dominant power sensing device used to measure pulsed RF signals. However, several diode
characteristics must be compensated to make meaningful measurements. These include the detector’s nonlinear amplitude
response, temperature sensitivity, and frequency response characteristic. Additional potential error sources include detector
mismatch, signal harmonics and noise.
Detector Response. The response of a single-diode detector to a sinusoidal input is given by the diode equation:
where:
i = diode current
v = net voltage across the diode
Is = saturation current
α = constant
An ideal diode response curve is plotted in Figure 6-3.
Figure 6-3.
Ideal Diode Response
The curve indicates that for low microwave input levels (Region A), the single-diode detector output is proportional to the
square of the input power. For high input signal levels (Region C), the output is linearly proportional to the input. In between
these ranges (Region B), the detector response lies between square-law and linear.
For accurate power measurements over all three regions illustrated in Figure 6-3, the detector response is pre-calibrated over
the entire range. The calibration data is stored in the instrument and recalled to adjust each sample of the pulse power
measurement.
Application Notes
6-3
Boonton 4240 Series RF Power Meter
Frequency Response. The carrier frequency response of a diode detector is determined mostly by the diode junction
capacitance and the device lead inductances. Accordingly, the frequency response will vary from detector to detector and
cannot be compensated readily. Power measurements must be corrected by constructing a frequency response calibration
table for each detector.
Mismatch. Sensor impedance matching errors can contribute significantly to measurement uncertainty, depending on the
mismatch between the device under test (DUT) and the sensor input. This error cannot be easily calibrated out, but can be
minimized by employing an optimum matching circuit at the sensor input.
Signal Harmonics. Measurement errors resulting from harmonics of the carrier frequency are level-dependent and cannot be
calibrated out. In the square-law region of the detector response (Region A, Figure 6-3), the signal and second harmonic
combine on a root mean square basis. The effects of harmonics on measurement accuracy in this region are relatively
insignificant. However, in the linear region (Region C, Figure 6-3), the detector responds to the vector sum of the signal and
harmonics. Depending on the relative amplitude and phase relationships between the harmonics and the fundamental,
measurement accuracy may be significantly degraded. Errors caused by even-order harmonics can be reduced by using
balanced diode detectors for the power sensor. This design responds to the peak-to-peak amplitude of the signal, which
remains constant for any phase relationship between fundamental and even-order harmonics. Unfortunately, for odd-order
harmonics, the peak-to-peak signal amplitude is sensitive to phasing, and balanced detectors provide no harmonic error
improvement.
Noise. For low-level signals, detector noise contributes to measurement uncertainty and cannot be calibrated out. Balanced
detector sensors improve the signal-to-noise ratio by 3 dB, because the signal is twice as large.
6.1.3 4240 Series Features
The 4240 Series design incorporates several significant features to reduce measurement error, simplify operation, and speed
internal processing. These features include:
6-4
•
Balanced diode sensors enhance error performance by increasing signal-to-noise and suppressing evenorder signal harmonics.
•
Smart Sensors (sensor-mounted EEPROM) store sensor frequency calibration eliminating operator entry.
•
Digital Signal Processor provides fast processing for near real-time measurements.
•
A built-in programmable calibrator which creates a unique calibration table for each sensor.
Application Notes
Boonton 4240 Series RF Power Meter
6.2 Measurement Accuracy
The 4240 Series includes a precision, internal, 50 MHz RF reference calibrator that is traceable to the National Institute for
Standards and Technology (NIST). When the instrument is maintained according to the factory recommended one year
calibration cycle, the calibrator enables you to make highly precise measurements of CW signals. The error analyses in this
chapter assumes that the power meter is being maintained correctly and is within its valid calibration period.
Measurement uncertainties are attributable to the instrument, calibrator, sensor, and impedance mismatch between the sensor
and the device under test (DUT). Individual independent contributions from each of these sources are combined
mathematically to quantify the upper error bound and probable error. The probable error is obtained by combining the linear
(percent) sources on a root-sum-of-squares (RSS) basis. RSS uncertainty calculations also take into account the statistical
shape of the expected error distribution.
Note that uncertainty figures for individual components may be provided given in either percent or dB. The following
formulas may be used to convert between the two units:
U% = (10(UdB/10) - 1) × 100
and
UdB = 10 × Log10(1 + (U% / 100))
Section 6.2.1 outlines all the parameters that contribute to the power measurement uncertainty followed by a discussion on
the method and calculations used to express the uncertainty.
Section 6.2.2 continues discussing each of the uncertainty terms in more detail while presenting some of their values.
Section 6.2.3 provides Power Measurement Uncertainty calculation example for a CW Power sensors with complete
Uncertainty Budgets.
6.2.1 Uncertainty Contributions.
The total measurement uncertainty is calculated by combining the following terms:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Uncertainty Source
Instrument Uncertainty
Calibrator Level Uncertainty
Calibrator Mismatch Uncertainty
Source Mismatch Uncertainty
Sensor Shaping Error
Sensor Temperature Coefficient
Sensor Noise
Sensor Zero Drift
Sensor Calibration Factor Uncertainty
Distribution Shape
Normal
Rectangular
U-shaped
U-shaped
Rectangular
Rectangular
Normal
Rectangular
Normal
K
0.500
0.577
0.707
0.707
0.577
0.577
0.500
0.577
0.500
The formula for worst-case measurement uncertainty is:
UWorstCase = U1 + U2 + U3 + U4 + ... UN
where U1 through UN represent each of the worst-case uncertainty terms.
Application Notes
6-5
Boonton 4240 Series RF Power Meter
The worst case approach is a very conservative method in which the extreme conditions of each of the individual
uncertainties are added together. If the individual uncertainties are all independent of one another, the probability of
all being at their worst-case conditions simultaneously is extremely small. For this reason, the uncertainties are more
commonly combined using the RSS method. RSS is an abbreviation for “root-sum-of-squares”, a technique in which
each uncertainty is squared, the squares are summed, and the square root of the summation is calculated.
Before the RSS calculation can be performed, however, the worst-case uncertainty values must be scaled, or
“normalized” to adjust for differences in each term’s probability distribution or “shape”. The distribution shape is a
statistical description of how the actual error values are likely to vary from the ideal value. Once normalized in this
way, terms with different distribution shapes can be combined freely using the RSS method.
Three main types of distributions are Normal (Gaussian), Rectangular, and U-shaped. The multipliers for each type of
distribution are as follows:
Distribution
Normal
Rectangular
U-shaped
Multiplier “K”
0.500
sqrt(1/3) = 0.577
sqrt(1/2) = 0.707
The formula for calculating RSS measurement uncertainty from worst-case values and scale factors is:
‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗‗
URSS = √ (U1K1)2 + (U2K2)2 + (U3K3)2 + (U4K4)2 + ... (UNKN)2
where U1 through UN represent each of the worst-case uncertainty terms, and K1 through KN represent the normalizing
multipliers for each term based on its distribution shape.
This calculation yields what is commonly referred to as the combined standard uncertainty, or UC, with a level of
confidence of approximately 68%. To gain higher levels of confidence an Expanded Uncertainty is often employed.
Using a coverage factor of 2 (U = 2UC ) will provide an Expanded Uncertainty with a confidence level of
approximately 95%.
6.2.2 Discussion of Uncertainty Terms.
Following is a discussion of each term, its definition, and how it is calculated.
Instrument Uncertainty. This term represents the amplification and digitization uncertainty in the power meter, as
well as internal component temperature drift. In most cases, this is very small, since absolute errors in the circuitry
are calibrated out by the AutoCal process. The instrument uncertainty is 0.23% for the 4240 Series.
Calibrator Level Uncertainty. This term is the uncertainty in the calibrator’s output level for a given setting for
calibrators that are maintained in calibrated condition. The figure is a calibrator specification which depends upon
the output level:
50MHz Calibrator Level Uncertainty:
At 0 dBm:
±0.055 dB (1.27%)
+20 to -39 dBm: ±0.075 dB (1.74%)
-40 to -60 dBm: ±0.105 dB (2.45%)
6-6
Application Notes
Boonton 4240 Series RF Power Meter
The value to use for calibration level uncertainty depends upon the sensor calibration technique used. If AutoCal
was performed, the calibrator’s uncertainty at the measurement power level should be used. For sensors calibrated
with FixedCal, the calibrator is only used as a single-level source, and you should use the calibrator’s uncertainty at
the FixedCal level, (0dBm, for most sensors). This may make FixedCal seem more accurate than AutoCal at some
levels, but this is usually more than offset by the reduction in shaping error afforded by the AutoCal technique.
Calibrator Mismatch Uncertainty. This term is the mismatch error caused by impedance differences between the
calibrator output and the sensor’s termination. It is calculated from the reflection coefficients of the calibrator (ρCAL)
and sensor (ρSNSR) at the calibration frequency with the following equation:
Calibrator Mismatch Uncertainty = ±2 × ρCAL × ρSNSR × 100 %
The calibrator reflection coefficient is a calibrator specification:
50 MHz Calibrator Reflection Coefficient (ρCAL):
0.024 (at 50MHz)
The sensor reflection coefficient, ρSNSR is frequency dependent, and may be looked up in the sensor datasheet or the
Boonton Electronics Power Sensor Manual.
Source Mismatch Uncertainty. This term is the mismatch error caused by impedance differences between the
measurement source output and the sensor’s termination. It is calculated from the reflection coefficients of the
source (ρSRCE) and sensor (ρSNSR) at the measurement frequency with the following equation:
Source Mismatch Uncertainty = ±2 × ρSRCE × ρSNSR × 100 %
The source reflection coefficient is a characteristic of the RF source under test. If only the SWR of the source is
known, its reflection coefficient may be calculated from the source SWR using the following equation:
Source Reflection Coefficient (ρSRCE) = (SWR - 1) / (SWR + 1)
The sensor reflection coefficient, ρSNSR is frequency dependent, and may be looked up in the sensor datasheet or the
Boonton Electronics Power Sensor Manual. For most measurements, this is the single largest error term, and care
should be used to ensure the best possible match between source and sensor.
Sensor Shaping Error. This term is sometimes called “linearity error”, and is the residual non-linearity in the
measurement after an AutoCal has been performed to characterize the “transfer function” of the sensor (the
relationship between applied RF power, and sensor output, or “shaping”). Calibration is performed at discrete level
steps and is extended to all levels. Generally, sensor shaping error is close to zero at the autocal points, and
increases in between due to imperfections in the curve-fitting algorithm.
An additional component of sensor shaping error is due to the fact that the sensor’s transfer function may not be
identical at all frequencies. The published shaping error includes terms to account for these deviations. If your
measurement frequency is close to your AutoCal frequency, it is probably acceptable to use a value lower than the
published uncertainty in your calculations.
For CW sensors using the fixed-cal method of calibrating, the shaping error is higher because it relies upon stored
"shaping coefficients" from a factory calibration to describe the shape of the transfer function, rather than a transfer
calibration using a precision power reference at the current time and temperature. For this reason, use of the AutoCal
method is recommended for CW sensors rather than simply performing a FixedCal. The shaping error for CW
sensors using the FixedCal calibration method is listed as part of the "Sensor Characteristics" outlined in Section 2
of the Boonton Electronics Power Sensor Manual. If the AutoCal calibration method is used with a CW sensor, a
fixed value of 1.0% may be used for all signal levels.
Application Notes
6-7
Boonton 4240 Series RF Power Meter
Sensor Temperature Coefficient. This term is the error which occurs when the sensor’s temperature has changed
significantly from the temperature at which the sensor was AutoCal’d. Refer to the Boonton Electronics Power
Sensor Manual for the Temperature Coefficient for the sensor being used.
Sensor Noise. For CW measurements it depends on the integration time of the measurement, which is set by the
“AVG” menu setting. In general, increasing averaging reduces measurement noise. Sensor noise is typically
expressed as an absolute power level. The uncertainty due to noise depends upon the ratio of the noise to the signal
power being measured. The following expression is used to calculate uncertainty due to noise:
Noise Error = ± Sensor Noise (in watts) / Signal Power (in watts) × 100 %
The noise rating of a particular power sensor may be found on the sensor datasheet, or the Boonton Electronics
Power Sensor Manual. It may be necessary to adjust the sensor noise for more or less averaging, depending upon
the application. As a general rule (within a decade of the datasheet point), noise is inversely proportional to the
filter time or averaging used. Noise error is usually insignificant when measuring at high levels (25dB or more
above the sensor’s minimum power rating).
Sensor Zero Drift. Zero drift is the long-term change in the zero-power reading that is not a random, noise
component. Increasing averaging will not reduce zero drift. For low-level measurements, this can be controlled by
zeroing the meter just before performing the measurement. Zero drift is typically expressed as an absolute power
level, and its error contribution may be calculated with the following formula:
Zero Drift Error = ± Sensor Zero Drift (in watts) / Signal Power (in watts) × 100 %
The zero drift rating of a particular power sensor may be found on the sensor datasheet, or the Boonton Electronics
Power Sensor Manual. Zero drift error is usually insignificant when measuring at high levels (25dB or more above
the sensor’s minimum power rating). The drift specification usually indicates a time interval such as one hour. If
the time since performing a sensor Zero or AutoCal is very short, the zero drift is greatly reduced.
Sensor Calibration Factor Uncertainty. Sensor frequency calibration factors (“calfactors”) are used to correct for
sensor frequency response deviations. These calfactors are characterized during factory calibration of each sensor
by measuring its output at a series of test frequencies spanning its full operating range, and storing the ratio of the
actual applied power to the measured power at each frequency. This ratio is called a calfactor. During measurement
operation, the power reading is multiplied by the calfactor for the current measurement frequency to correct the
reading for a flat response.
The sensor calfactor uncertainty is due to uncertainties encountered while performing this frequency calibration (due
to both standards uncertainty, and measurement uncertainty), and is different for each frequency. Both worst case
and RSS uncertainties are provided for the frequency range covered by each sensor, and are listed on the sensor
datasheet and in the Boonton Electronics Power Sensor Manual.
If the measurement frequency is between sensor calfactor entries, the most conservative approach is to use the
higher of the two corresponding uncertainty figures. It is also be possible to estimate the figure by linear
interpolation.
If the measurement frequency is identical to the AutoCal frequency, a calfactor uncertainty of zero should be used,
since any absolute error in the calfactor cancels out during AutoCal. At frequencies that are close to the AutoCal
frequency, the calfactor uncertainty is only partially cancelled out during AutoCal, so it is generally acceptable to
take the uncertainty for the next closest frequency, and scale it down.
6-8
Application Notes
Boonton 4240 Series RF Power Meter
6.2.3 Sample Uncertainty Calculations.
The following example shows calculations for a CW power sensors. The figures used in these examples are meant to show
the general technique, and do not apply to every application. Some “common sense” assumptions have been made to
illustrate the fact that uncertainty calculation is not an exact science, and requires some understanding of your specific
measurement conditions.
Typical Example #1: Model 51075 CW Power Sensor
4240 Series measurement conditions:
Source Frequency:
10.3 GHz
Source Power:
-55 dBm (3.16 nW)
Source SWR :
.50 (reflection coefficient = 0.2) at 10.3 GHz
AutoCal Source:
Internal 50MHz Calibrator
AutoCal Temperature:
25C
Current Temperature:
25C
In this example, we will assume that an AutoCal has been performed on the sensor immediately before the measurement.This
will reduce certain uncertainty terms, as discussed below.
Step 1: The Instrument Uncertainty figure for the 4240 Series is ± 0.23%. Since a portion of this figure is meant to include
temperature drift of the instrument, and we know an AutoCal has just been performed, we’ll estimate (for lack of more
detailed, published information) that the instrument uncertainty is ± 0.115%, or half the published figure.
UInstrument
= ± 0.115%
Step 2: The Calibrator Level Uncertainty for the power meter’s 50MHz calibrator may be read from the calibrator’s
specification. It is ± 0.105dB, or ± 2.45% at a level of -55dBm.
= ± 2.45%
UCalLevel
Step 3: The Calibrator Mismatch Uncertainty is calculated using the formula in the previous section, using the 50MHz
calibrator’s published figure for ρCAL and calculating the value ρSNSR from the SWR specification on the 51075’s datasheet.
ρCAL = 0.024 (calibrator’s reflection coefficient at 50MHz)
ρSNSR = (1.15 - 1) / (1.15 + 1) = 0.070 (calculate reflection coefficient of 51075, max SWR = 1.15 at 50MHz)
UCalMismatch
= ± 2 × ρCAL × ρSNSR × 100 %
= ± 2 × 0.024 × 0.070 × 100 %
= ± 0.34%
Step 4: The Source Mismatch Uncertainty is calculated using the formula in the previous section, using the DUT’s
specification for ρSRCE and calculating the value ρSNSR from the SWR specification on the 51075’s datasheet.
ρSRCE = 0.20 (source reflection coefficient at 10.3GHz)
ρSNSR = (1.40 - 1) / (1.40 + 1) = 0.167 (calculate reflection coefficient of 51075, max SWR = 1.40 at 10.3GHz)
USourceMismatch
= ± 2 × ρSRCE × ρSNSR × 100 %
= ± 2 × 0.20 × 0.167 × 100 %
= ± 6.68%
Step 5: The uncertainty caused by Sensor Shaping Error for a 51075 CW sensor that has been calibrated using the AutoCal
method can be assumed to be 1.0%, as per the discussion in the previous section.
UShapingError
= ± 1.0 %
Application Notes
6-9
Boonton 4240 Series RF Power Meter
Step 6: The Sensor Temperature Drift Error depends on how far the temperature has drifted from the sensor calibration
temperature, and the temperature coefficient of the sensor. In this example, an AutoCal has just been performed on the
sensor, and the temperature has not drifted at all, so we can assume a value of zero for sensor temperature drift uncertainty.
USnsrTempDrift
= ± 0.0 %
Step 7: This is a relatively low-level measurement, so the noise contribution of the sensor must be included in the uncertainty
calculations. We’ll assume default filtering. The signal level is -55dBm, or 3.16nW. The RMS noise specification for the
51075 sensor is 30pW, from the sensor’s datasheet. Noise uncertainty is the ratio of these two figures.
= ± (Sensor Noise (in watts) / Signal Power (in watts)) × 100%
UNoise Error
= ± (30.0e-12 / 3.16e-9) × 100 %
= ± 0.95%
Step 8: The Sensor Zero Drift calculation is very similar to the noise calculation. For sensor zero drift, the datasheet
specification for the 51075 sensor is 100pW, so we’ll take the liberty of cutting this in half to 50pW, since we just performed
an AutoCal, and it’s likely that the sensor hasn’t drifted much.
UZero Drift
= ± (Sensor Zero Drift (in watts) / Signal Power (in watts)) × 100%
= ± (50.0e-12 / 3.16e-9) × 100 %
= ± 1.58%
Step 9: The Sensor Calfactor Uncertainty is calculated from the uncertainty values in the Boonton Electronics Power Sensor
Manual. There is no entry for 10.3GHz, so we’ll have to look at the two closest entries. At 10GHz, the calfactor uncertainty
is 4.0%, and at 11GHz it is 4.3%. These two values are fairly close, so we’ll perform a linear interpolation to estimate the
uncertainty at 10.3GHz:
UCalFactor
= [ ( F - F1 ) * (( CF2 - CF1 ) / ( F2 - F1 )) ] + CF1
= [ ( 10.3 - 10.0 ) * (( 4.3 - 4.0 ) / ( 11.0 - 10.0 )) ] + 4.0
= 4.09%
6-10
Application Notes
Boonton 4240 Series RF Power Meter
Step 10: Now that each of the individual uncertainty terms has been determined, we can combine them to calculate the worstcase and RSS uncertainty values:
U (±%)
K
(U×K)2 ( %2 )
1. instrument uncertainty
0.115
0.500
0.0033
2. calibrator level uncertainty
2.45
0.577
1.9984
3. calibrator mismatch uncertainty
0.34
0.707
0.0578
4. source mismatch uncertainty
6.68
0.707
22.305
5. sensor shaping error uncertainty
1.00
0.577
0.3333
6. sensor temperature drift uncertainty 0.00
0.577
0.0000
7. sensor noise uncertainty
0.95
0.500
0.2256
8. sensor zero drift uncertainty
1.58
0.577
0.8311
9. sensor calibration factor uncertainty 4.09
0.500
4.1820
___________________________
Total worst case uncertainty:
±17.21%
Total sum of squares:
Combined Standard uncertainty UC (RSS) :
Expanded Uncertainty U (coverage factor k = 2) :
29.937 %2
±5.47 %
±10.94 %
From this example, it can be seen that the two largest contributions to total uncertainty are the source mismatch, and the
sensor calfactor. Also note that the expanded uncertainty is approximately one-half the value of the worst-case uncertainty.
This is not surprising, since the majority of the uncertainty comes from just two sources. If the measurement frequency was
lower, these two terms would be reduced, and the expanded uncertainty would probably be less than half the worst-case.
Conversely, if one term dominated (for example if a very low level measurement was being performed, and the noise
uncertainty was 30%), the expanded uncertainty value would be expected to approach the worst-case value. The expanded
uncertainty is 0.45 dB.
It should be noted that measurement uncertainty calculation is a very complex process, and the techniques shown here are
somewhat simplified to allow easier calculation. For a more complete information, the following publications may be
consulted:
1.
“ISO Guide to the Expression of Uncertainty in Measurement” (1995)
International Organization for Standardization, Geneva, Switzerland
ISBN 92-67-10188-9
2.
“U.S. Guide to the Expression of Uncertainty in Measurement” (1996)
National Conference of Standards Laboratories, Boulder, CO 80301
ANSI/NCSL Z540-2-1996
Application Notes
6-11
Boonton 4240 Series RF Power Meter
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6-12
Application Notes
Boonton 4240 Series RF Power Meter
7. Maintenance
This section presents procedures for maintaining the 4240 Series.
7.1 Safety
Although the 4240 Series has been designed in accordance with international safety standards,
general safety precautions must be observed during all phases of operation and maintenance.
Failure to comply with the precautions listed in the Safety Summary located in the front of this
manual could result in serious injury or death. Service and adjustments should be performed only
by qualified service personnel.
7.2 Cleaning
Painted surfaces can be cleaned with a commercial spray-type window cleaner or a mild detergent
and water solution.
CAUTION
Avoid using chemical cleaning agents which can damage painted or plastic surfaces.
7.3 Inspection
If a 4240 Series instrument malfunctions, perform a visual inspection of the instrument. Inspect
for signs of damage caused by excessive shock, vibration or overheating. Inspect for broken
wires, loose electrical connections, or accumulations of dust or other foreign matter.
Correct any problems you discover and conduct a performance test to verify that the instrument is
operational. If the malfunction persists of the instrument fails the performance verification, contact
Boonton Electronics for service.
7.4 Firmware Upgrade
Operating Firmware has been loaded into the 4240 Series instrument at the factory. The Firmware
will be updated from time to time to correct errors and add new features. Users can upgrade their
firmware by downloading a special Firmware Upgrade file from the Boonton Electronics
webpage, www.boonton.com.
Maintenance
7-1
Boonton 4240 Series RF Power Meter
7.5 Firmware Upgrade Instructions
Requirements
The Firmware Update file is a text file in S-record format. Any utility that can send a text file over
the GPIB interface could be used, however, it is recommended that National Instruments VISA
Interactive Controller (VIC) utility that is available with installation of their VISA (Virtual
Instrument Software Architecture) product be used as this has been tried and tested. Please refer to
the specific vendor’s website for license and download details.
Procedure
7-2
1.
Save the file "Srecord_4240.hex" to your hard drive in a folder such as "C:\4240\Update"
2.
On the 4240 configure the following IEEE parameters as shown;
EMULATION 4230
EOS LSTN
LF
3.
Start the VISA Interactive Controller utility
4.
Double click on the 4240 Resource (in this example ‘GPIB0::13::INSTR’) to open a VISA
Session. Ensure that the ‘Show All VISA Operations’ box is checked. Then click the ‘Basic
I/O’ tab and then the ‘viWriteFromFile’ tab on that form.
5.
Set the count to 2000000 then either Browse for or enter the Filename.
6.
Click the ‘Execute’ button to send the file to the instrument.
Maintenance
Boonton 4240 Series RF Power Meter
7.
During this time the 4240 will display "FIRMWARE DOWNLOAD". The download takes
approximate 45 seconds to completely transfer.
8.
When the End-Of-File is reached the message “PROGRAMMING FLASH” will be
displayed on the 4240. Flash programming takes approximately 5 seconds to complete.
9.
When programming is complete the instrument returns to the measurement display.
10. At this time cycle the power to the instrument to run the new firmware.
11. Note the ‘Rev.’ number should indicate the latest revision. For example: 20100717.
Maintenance
7-3
Boonton 4240 Series RF Power Meter
This page intentionally left blank.
7-4
Maintenance
Boonton 4240 Series RF Power Meter
8. Appendix A
SCPI Error Messages
8.1 SCPI Error Messages
NO.
0
MESSAGE
DESCRIPTION
“No Error”
-100
"Command Error"
-101
“SubCmd not found”
-102
"Syntax error"
-103
“Too many qry”
-108
"Parameter not allowed"
-109
"Missing parameter"
-113
"Undefined header"
-115
“Channel out of range”
-121
“Invalid argument”
-131
"Invalid suffix"
-200
“Execution error”
-213
"Init ignored”
-221
"Settings conflict"
-222
"Data out of range"
-224
"Illegal parameter value"
-227
"CAL Level > Limit"
-240
“Hardware Error”
-241
"Error hardware missing"
-242
"CH2 Not Responding"
Channel 2 is not responding to instrument control.
-243
"CH1 Not Responding"
Channel 1 is not responding to instrument control.
-244
"No channel responding"
CH1 and CH2 do not respond to instrument control.
Attempt to set the calibrator level greater than the Max Power level.
Appendix A
8-1
Boonton 4240 Series RF Power Meter
NO.
MESSAGE
DESCRIPTION
-245
"Sensor Disconnected."
-246
“Sensor voltage error”
-247
"No Calibrator"
-248
"Keyboard error"
-249
"FPGA download err"
-263
“MFS Init”
-264
“Flash init”
-266
“Mem restore”
-280
“Program error”
-295
"Command not in language."
-296
"Data out of range, set to limit."
-297
"Command not supported."
-313
“Cal mem lost”
-340
“Calibration failed”
-350
"Error queue overflow"
-360
“Communication Error”
-362
“Snsr2 Page Blank”
-363
“Snsr1 Page Blank”
-364
“Sensor access fault”
-371
"Err CH2 Sensor Data"
Checksum failure of the Channel 2 sensor EEPROM.
-372
"Err CH1 Sensor Data"
Checksum failure of the Channel 1 sensor EEPROM .
-373
“Measurement Error”
-375
"Cmd not accepted"
-376
"I2C Timeout"
Software has timed-out while communicating over the I2C bus.
-377
"No I2C Ack"
Missing Acknowledge signal while assessing the I2C bus.
-397
"Err CW signal."
8-2
The calibrator is not responding to instrument control.
Appendix A
Boonton 4240 Series RF Power Meter
9. Appendix B Warranty & Repair
Repair Policy
4240 Series Instrument.
If the Boonton 4240 Series RF Power Meter is not operating correctly and requires service, contact the Boonton Electronics
Service Department for return authorization. You will be provided with an RMA number and shipping instructions.
Customers outside the USA should contact the authorized Boonton distributor for your area. The entire instrument must be
returned in its original packing container. If the original container is not available, Boonton Electronics will ship a
replacement container and you will be billed for the container cost and shipping charges. See section 2.1 of this manual for
packing instructions.
Boonton Power Sensors.
Damaged or defective peak power sensors are repaired as separate accessories. Note that sensors which have failed due to
overloading, improper mating, or connecting to an out-of-tolerance connector are not considered defective and will not be
covered by the Boonton Warranty. If repair is needed, contact the Boonton Electronics Service Department for return
authorization. You will be provided with an RMA number and shipping instructions. Customers outside the USA should
contact the authorized Boonton distributor for your area. Only the defective sensor should be returned to Boonton, not the
entire instrument. The sensor must be returned in its original packing container. If the original container is not available,
Boonton Electronics will ship a replacement container and you will be billed for the container cost and shipping charges. If a
new sensor is ordered, note that it does not include a sensor cable - this item must be ordered separately.
Contacting Boonton.
Customers in the United States having questions or equipment problems may contact Boonton Electronics directly during
business hours (8 AM to 5 PM Eastern) by phoning (973) 386-9696. FAX messages may be sent at any time to (973) 3869191. E-mail inquiries should be sent to [email protected] International customers should contact their
authorized Boonton Electronics representative for assistance. A current list of authorized US and international representatives
is available on the Boonton website at www.boonton.com.
HT
HT
TH
TH
Limited Warranty
Boonton Electronics warrants its products to the original Purchaser to be free from defects in material and workmanship and
to operate within applicable specifications for a period of one year from date of shipment for instruments, probes, power
sensors and accessories. Boonton Electronics further warrants that its instruments will perform within all current
specifications under normal use and service for one year from date of shipment. These warranties do not cover active devices
that have given normal service, sealed assemblies which have been opened, or any item which has been repaired or altered
without Boonton’s authorization.
Boonton’s warranties are limited to either the repair or replacement, at Boonton’s option, of any product found to be
defective under the terms of these warranties.
There will be no charge for parts and labor during the warranty period. The Purchaser shall prepay inbound shipping charges
to Boonton or its designated service facility and shall return the product in its original or an equivalent shipping container.
Boonton or its designated service facility shall pay shipping charges to return the product to the Purchaser for domestic
shipping addresses. For addresses outside the United States, the Purchaser is responsible for prepaying all shipping charges,
duties and taxes (both inbound and outbound).
At Boonton's option, an extended Warranty period may be available for an additional charge. If an extended warranty option
has been purchased, the extended period is substituted for the 1 year period above. Note that the extended warranty does not
extend the instrument's calibration interval past 12 months. The instrument must be maintained in a calibrated state
throughout the warranty period to be eligible for warranty service to remedy "out of spec"operation.
Appendix B
9-1
Boonton 4240 Series RF Power Meter
THE FOREGOING WARRANTIES ARE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR
IMPLIED, INCLUD-ING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PAR-TICULAR PURPOSE. Boonton will not be liable
for any incidental damages or for any consequential damages, as defined in Section 2-715 of the
Uniform Commercial Code, in connection with products covered by the foregoing warranties.
END OF 4240 SERIES MANUAL
9-2
Appendix B
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