Agilent N1914A Programming Guide

Agilent
N1913/1914A
EPM Series Power
Meters

Programming Guide

Agilent Technologies

Notices

CAUTION

WARNING

© Agilent Technolo gies, Inc. 2009

No p art o f this manual may b e rep roduced in
any form or by any means (including elec­tronic storage and retrieval or translation
into a foreign language) without prior agree­ment and written consent from Agilent
Technologies, Inc. as governed by United
States and international copyright laws.

Manual Part Number

N1913-90008

Edition

First Edition, May 13, 2009

Printed in Malaysia

Agilent Technologies, Inc.
5301 Stevens Creek Blvd.
Santa Clara, CA 95051 USA

Warranty

The material contained in this docu­ment is provided “as is,” and is sub­ject to being changed, without notice,
in future editions. Further, to the max­imum extent permitted by applicable
law, Agilent disclaims all warranties,
either express or implied, with regard
to this manual and any information
contained herein, including but not
limited to the implied warranties of
merchantability and fitness for a par­ticular purpose. Agilent shall not be
liable for errors or for incidental or
consequential damages in connec­tion with the furnishing, use, or per­formance of this document or of any
information contained herein. Should
Agilent and the user have a separate
written agreement with warranty
terms covering the material in this
document that conflict with these
terms, the warranty terms in the sep­arate agreement shall control.

Technology Licenses

The hardware and/or software described in
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and may be used or copied only in accor­dance with the terms of such license.

Restricted Rights Legend

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the federal government include only those
rights customarily provided to end user cus­tomers. Agilent provides this customary
commercial license in Software and techni­cal data pursuant to FAR 12.211 (Technical
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for the Department of Defense, DFARS

252.227-7015 (Technical Data - Commercial
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Commercial Computer Software or Com­puter Software Documentation).

Safety Notices

A CAUTION notice denotes a haz-
ard. It calls attention to an operat­ing procedure, practice, or the like
that, if not correctly performed or
adhered to, could result in damage
to the product or loss of important
data. Do not proceed beyond a
CAUTION notice until the indicated
conditions are fully understood and
met.

A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly per­formed or adhered to, could result
in personal injury or death. Do not
proceed beyond a WARNING
notice until the indicated condi­tions are fully understood and
met.

ii N1913A/1914A EPM Series Power Meters Programming Guide

General Warranty

The material contained in this document is provided “as is,” and is subject
to being changed, without notice, in future editions. Further, to the
maximum extent permitted by applicable law, Agilent disclaims all
warranties, either express or implied with regard to this manual and any
information contained herein, including but not limited to the implied
warranties of merchantability and fitness for a particular purpose. Agilent
shall not be liable for errors or for incidental or consequential damages in
connection with the furnishing, use, or performance of this document or
any information contained herein. Should Agilent and the user have a
separate written agreement with warranty terms covering the material in
this document that conflict with these terms, the warranty terms in the
separate agreement shall control. Duration and conditions of warranty for
this product may be superseded when the product is integrated into
(becomes a part of) other Agilent products. During the warranty period,
Agilent will, at its option, either repair or replace products which prove to
be defective. The warranty period begins on the date of delivery or on the
date of installation if installed by Agilent.

Restricted Rights Legend

The Software and Documentation have been developed entirely at private
expense. They are delivered and licensed as “commercial computer
software” as defined in DFARS 252.227-7013 (Oct 1988), DFARS

252.211-7015 (May 1991), or DFARS 252.227-7014 (Jun 1995), as a
“commercial item” as defined in FAR 2.101(a), or as “restricted computer
software” as defined in FAR 52.227-19 (Jun 1987) (or any equivalent
agency regulation or contract clause), whichever is applicable. You have
only those rights provided for such Software and Documentation by the
applicable FAR or DFARS clause or the Agilent standard software
agreement for the product involved.

N1913A/1914A EPM Series Power Meters Programming Guide iii

Equipment Operation

WARNING

CAUTION

Warnings and Cautions

This guide uses warnings and cautions to denote hazards.

A WARNING notice denotes a hazard. It calls attention to an operating
procedure, practice, or the like that, if not correctly performed or
adhered to, could result in personal injury or loss of life. Do not proceed
beyond a WARNING notice until the indicated conditions are fully
understood and met.

A CAUTION notice denotes a hazard. It calls attention to an operating
procedure, practice, or the like that, if not correctly performed or adhered
to, could result in damage to the product or loss of important data. Do not
proceed beyond a CAUTION notice until the indicated conditions are fully
understood and met.

Personal Safety Considerations

This is a Safety Class I product (provided with a protective earthing ground
incorporated in the power cord). The mains plug shall only be inserted in a
socket outlet provided with a protective earth contact. Any interruption of
the protective conductor, inside or outside the instrument, is likely to make
the instrument dangerous. Intentional interruption is prohibited. If this
instrument is not used as specified, the protection provided by the
equipment could be impaired. This instrument must be used in a normal
condition (in which all means of protection are intact) only.

iv N1913A/1914A EPM Series Power Meters Programming Guide

No operator serviceable parts inside. Refer servicing to qualified
personnel. To prevent electrical shock, do not remove covers. For
continued protection against fire hazard, replace the line fuse(s) only with
fuses of the same type and rating (for example, normal blow, time delay,
etc.). The use of other fuses or material is prohibited.

General Safety Considerations

WARNING

CAUTION

The following general safety precautions must be observed during all
phases of operation 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. Agilent Technologies, Inc. assumes no liability for the
customer’s failure to comply with these requirements.

• Before this instrument is switched on, make sure it has been
properly grounded through the protective conductor of the ac power
cable to a socket outlet provided with protective earth contact. Any
interruption of the protective (grounding) conductor, inside or
outside the instrument, or disconnection of the protective earth
terminal can result in personal injury.

• Any adjustments or service procedures that require operation of the
instrument with protective covers removed should be performed only
by trained service personnel.

User Environment

N1913A/1914A EPM Series Power Meters Programming Guide v

This instrument is designed for indoor use only.

In This Guide ...

Power Meter Remote Operation

1

that configure the power meter and helps you determine settings to
optimize performance.

MEASurement Commands

2

group of instructions to acquire data using a set of high level instructions.

CALCulate Subsystem

3

subsystem is used to perform post acquisition data processing.

CALibration Subsystem

4

command subsystem is used to zero and calibrate the power meter.

DISPlay Subsystem

5

used to control the selection and presentation of the windows used on the
power meter’s display.

FORMat Subsystem

6

used to set a data format for transferring numeric information.

MEMory Subsystem

7

subsystem is used to create, edit, and review sensor calibration tables.

OUTPut Subsystem

8

subsystem is used to switch the POWER REF output on and off.

Chapter 3 explains how the CALCulate

Chapter 4 explains how the CALibration

Chapter 5 explains how the DISPlay subsystem is

Chapter 6 explains how the FORMat subsystem is

Chapter 7 explains how the MEMory command

Chapter 8 explains how the OUTPut command

Chapter 1 describes the parameters

Chapter 2 explains how to use the MEASure

SENSe Subsystem

9

subsystem directly affects device specific settings that are used to make
measurements.

STATus Subsystem

10

subsystem enables you to examine the status of the power meter by
monitoring the “Device Status Register”, “Operation Status Register” and
the “Questionable Status Register”.

vi N1913A/1914A EPM Series Power Meters Programming Guide

Chapter 9 explains how the SENSe command

Chapter 10 explains how the STATus command

SYSTem Subsystem

11

subsystem is used to return error numbers and messages from the power
meter, preset the power meter, set the remote address, and query the SCPI
version.

Chapter 11 explains how the SYSTem command

TRIGger Subsystem

12

subsystem is used to synchronize device actions with events.

UNIT Subsystem

13

subsystem is used to set the power meter measurement units to Watts
and % (linear), or dBm and dB (logarithmic).

SERVice Subsystem

14

subsystem is used to obtain and set information useful for servicing the
power meter.

IEEE 488.2 Command Reference

15

the IEEE488.2 Common Commands that the power meter supports.

Programming Examples

16

and examples to remotely control the EPM Series power meters using
SCPI commands.

Calibration Factor Block Layout

A

the calibration factor block layout for E4410 Series, E9300 Series, and
N8480 Series sensors (excluding Option CFT).

Measurement Polling Example

B

example of VEE program in measurement polling.

Chapter 12 explains how the TRIGger command

Chapter 13 explains how the UNIT command

Chapter 14 explains how the SERVice command

Chapter 15 contains information about

Chapter 16 contains programming sequences

Appendix A contains information on

Appendix B contains information on

HP436A/HP437B/HP438A Command Summary

C

information on the HP436A/HP437B/HP438A command summary.

N1913A/1914A EPM Series Power Meters Programming Guide vii

Appendix C contains

viii N1913A/1914A EPM Series Power Meters Programming Guide

Contents

Notices ii
General Warranty iii
Restricted Rights Legend iii
Equipment Operation iv
General Safety Considerations v
User Environment v
In This Guide ... vi

1 Power Meter Remote Operation

Introduction 4
Configuring the Remote Interface 5

• Interface Selection 5

• GPIB Address 5

• LAN Configuration 6

• USB Configuration 7

Zeroing and Calibrating 8

• Zeroing 8

• Calibration 9

Making Measurement 10

• Using MEASure? 11

• Using the CONFigure Command 16

• Using the Lower Level Commands 25

Using Frequency Dependent Offset Tables 27

• Overview 27

• Editing Frequency Dependent Offset Tables 29

• Selecting a Frequency Dependent Offset Table 32

• Enabling a Frequency Dependent Offset Table 32

• Making the Measurement 32

Setting the Range, Resolution and Averaging 34

• Resolution 34

• Averaging 34

• Auto Averaging Mode 35

• Filter Length 36

• Range 37

N1913/1914A EPM Series Power Meters Programming Guide ix

Setting Offsets 38

• Channel Offsets 38

• Display Offsets 38

Setting Measurement Limits 40

• Setting Limits 40

• Checking for Limit Failures 42

• Using STATus 43

Getting the Best Speed Performance 44

• Measurement Rate 44

• Sensor 45

• Trigger Mode 45

• Output Format 47

• Units 47

• Command Used 47

• Fast Mode 48

How Measurements are Calculated 49
Status Reporting 50

• The General Status Register Model 50

• How to Use Register 53

• The Condition Polling Method 53

• The SRQ Method 54

• Device Status Register 65

• Using the Operation Complete Commands 67

Saving and Recalling Power Meter Configurations 70

• How to Save and Recall a Configuration 70

Using Device Clear to Halt Measurements 71
An Introduction to the SCPI Language 72

• Mnemonic Forms 72

• Using a Colon (:) 72

• Using a Semicolon (;) 73

• Using a Comma (,) 73

• Using Whitespace 73

• Using “?” Commands 73

• Using “*” Commands 74

• Syntax Conventions 74

x N1913/1914A EPM Series Power Meters Programming Guide

• Syntax Diagram Conventions 74

• SCPI Data Types 75

• Input Message Terminators 80

SCPI Compliance Information 82
Summary of Commands 84

2 MEASurement Commands

MEASurement Commands 87
CONFigure[1] |2|3|4? 92
CONFigure [1] |2|3|4 Commands 97
CONFigure[1]|2|3|4[:SCALar][:POWer:AC] [<expected_value>[,<resolution>[,<source list>]]] 98
CONFigure[1]|2|3|4[:SCALar][:POWer:AC]:RELative [<expected_value>[,<resolution>[,<source

list>]]] 101
CONFigure[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence [<expected_value>[,<resolution>[,<source

list>]]] 104
CONFigure[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence: RELative

[<expected_value>[,<resolution>[,<source list>]]] 107
CONFigure[1]|2|3|4[:SCALar][:POWer:AC]:RATio [<expected_value>[,<resolution>[,<source

list>]]] 110
CONFigure[1]|2|3|4[:SCALar][:POWer:AC]:RATio: RELative[<expected_value>[,<resolution>[,<source

list>]]] 113
FETCh[1]|2|3|4 Queries 116
FETCh[1]|2|3|4[:SCALar][:POWer:AC]? [<expected_value>[,<resolution>[,<source list>]]] 117
FETCh[1]|2|3|4[:SCALar][:POWer:AC]:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 120
FETCh[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence? [<expected_value>[,<resolution>[,<source

list>]]] 123
FETCh[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence: RELative?

[<expected_value>[,<resolution>[,<source list>]]] 126
FETCh[1]|2|3|4[:SCALar][:POWer:AC]:RATio? [<expected_value>[,<resolution>[,<source list>]]] 129
FETCh[1]|2|3|4[:SCALar][:POWer:AC]:RATio:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 132
READ[1]|2|3|4 Commands 135
READ[1]|2|3|4[:SCALar][:POWer:AC]? [<expected_value>[,<resolution>[,<source list>]]] 136
READ[1]|2|3|4[:SCALar][:POWer:AC]:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 139

N1913/1914A EPM Series Power Meters Programming Guide xi

READ[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence? [<expected_value>[,<resolution>[,<source
list>]]] 142

READ[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence: RELative?
[<expected_value>[,<resolution>[,<source list>]]] 145

READ[1]|2|3|4[:SCALar][:POWer:AC]:RATio? [<expected_value>[,<resolution>[,<source list>]]] 148
READ[1]|2|3|4[:SCALar][:POWer:AC]:RATio:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 151
MEASure[1]|2|3|4 Commands 154
MEASure[1]|2|3|4[:SCALar][:POWer:AC]? [<expected_value>[,<resolution>[,<source list>]]] 155
MEASure[1]|2|3|4[:SCALar][:POWer:AC]:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 158
MEASure[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence? [<expected_value>[,<resolution>[,<source

list>]]] 161
MEASure[1]|2|3|4[:SCALar][:POWer:AC]:DIFFerence: RELative?

[<expected_value>[,<resolution>[,<source list>]]] 163
MEASure[1]|2|3|4[:SCALar][:POWer:AC]:RATio? [<expected_value>[,<resolution>[,<source

list>]]] 166
MEASure[1]|2|3|4[:SCALar][:POWer:AC]:RATio:RELative? [<expected_value>[,<resolution>[,<source

list>]]] 169

3 CALCulate Subsystem

CALCulate Subsystem 172
CALCulate[1]|2|3|4:HOLD:STAT <character_data> 175
CALCulate[1]|2|3|4:GAIN Commands 180
CALCulate[1]|2|3|4:GAIN[:MAGNitude] <numeric_value> 181
CALCulate[1]|2|3|4:GAIN:STATe <boolean> 183
CALCulate[1]|2|3|4:LIMit Commands 185
CALCulate[1]|2|3|4:LIMit:CLEar:AUTo <boolean>|ONCE 186
CALCulate[1]|2|3|4:LIMit:CLEar[:IMMediate] 188
CALCulate[1]|2|3|4:LIMit:FAIL? 189
CALCulate[1]|2|3|4:LIMit:FCOunt? 190
CALCulate[1]|2|3|4:LIMit:LOWer[:DATA] <numeric_value> 192
CALCulate[1]|2|3|4:LIMit:UPPer[:DATA] <numeric_value> 195
CALCulate[1]|2|3|4:LIMit:STATe <boolean> 198
CALCulate[1]|2|3|4:MATH Commands 200
CALCulate[1]|2|3|4:MATH[:EXPRession] <string> 201

xii N1913/1914A EPM Series Power Meters Programming Guide

CALCulate[1]|2|3|4:MATH[:EXPRession]:CATalog? 205
CALCulate[1]|2|3|4:RELative Commands 207
CALCulate[1]|2|3|4:RELative[:MAGNitude]:AUTO <boolean>|ONCE 208
CALCulate[1]|2|3|4:RELative:STATe <boolean> 210

4 CALibration Subsystem

CALibration Subsystem 214
CALibration[1]|2|3|4[:ALL] 216
CALibration[1]|2|3|4[:ALL]? 218
CALibration[1]|2|3|4:AUTO <boolean>|ONCE 220
CALibration[1]|2|3|4:RCALibration <boolean> 222
CALibration[1]|2|3|4:RCFactor <numeric_value> 224
CALibration[1]|2|3|4:ZERO:AUTO <boolean>|ONCE 226
CALibration3|4:ZERO:TYPE EXTernal|INTernal 228

5 DISPlay Subsystem

DISPlay Subsystem 232
DISPlay:ENABle <boolean> 233
DISPlay:SCReen:FORMat <character_data> 234
DISPlay[:WINDow[1]|2] Commands 236
DISPlay[:WINDow[1]|2]:ANALog Commands 237
DISPlay[:WINDow[1]|2]:ANALog:LOWer <numeric_value> 238
DISPlay[:WINDow[1]|2]:ANALog:UPPer <numeric_value> 241
DISPlay[:WINDow[1]|2]:METer Commands 244
DISPlay[:WINDow[1]|2]:METer:LOWer <numeric_value> 245
DISPlay[:WINDow[1]|2]:METer:UPPer <numeric_value> 248
DISPlay[:WINDow[1]|2][:NUMeric[1]|2]:RESolution <numeric_value> 251
DISPlay[:WINDow[1]|2]:SELect[1]|2 253
DISPlay[:WINDow[1]|2][:STATe] <boolean> 255
DISPlay[:WINDow[1]|2]:TRACe:FEED <character_data> 257

6 FORMat Subsystem

FORMat Subsystem 260
FORMat[:READings]:BORDer <character_data> 261
FORMat[:READings][:DATA] <character_data> 263

N1913/1914A EPM Series Power Meters Programming Guide xiii

7 MEMory Subsystem

MEMory Subsystem 266
MEMory[:METer]|:USB[1]|2:CATalog Commands 268
MEMory[:METer]|:USB[1]|2:CATalog[:ALL]? 269
MEMory[:METer]|:USB[1]|2:CATalog:STATe? 272
MEMory[:METer]|:USB[1]|2:CATalog:TABLe? 274
MEMory[:METer]|:USB[1]|2:CLEar Commands 277
MEMory[:METer]|:USB[1]|2:CLEar[:NAME] <character_data> 278
MEMory[:METer]|:USB[1]|2:CLEar:TABLe 280
MEMory[:METer]|:USB[1]|2:FREE Commands 281
MEMory[:METer]|:USB[1]|2:FREE[:ALL]? 282
MEMory[:METer]|:USB[1]|2:FREE:STATe? 283
MEMory[:METer]|:USB[1]|2:FREE:TABLe? 284
MEMory[:METer]|:USB[1]|2:NSTates? 285
MEMory[:METer]|:USB[1]|2:STATe Commands 286
MEMory[:METer]|:USB[1]|2:STATe:CATalog? 287
MEMory[:METer]|:USB[1]|2:STATe:DEFine <character_data>,<numeric_value> 288
MEMory[:METer]|:USB[1]|2:TABLe Commands 290
MEMory[:METer]|:USB[1]|2:TABLe:FREQuency <numeric_value>{,<numeric_value>} 291
MEMory[:METer]|:USB[1]|2:TABLe:FREQuency:POINts? 295
MEMory[:METer]|:USB[1]|2:TABLe:GAIN[:MAGNitude] <numeric_value>{,<numeric_value>} 296
MEMory[:METer]|:USB[1]|2:TABLe:GAIN[:MAGNitude]:POINts? 299
MEMory[:METer]|:USB[1]|2:TABLe:MOVE <character_data>,<character_data> 300
MEMory[:METer]|:USB[1]|2:TABLe:SELect <character_data> 302

8 OUTPut Subsystem

OUTPut Subsystem 304
OUTPut:RECorder[1]|2:FEED <data_handle> 305
OUTPut:RECorder[1]|2:LIMit:LOWer <numeric_value> 307
OUTPut:RECorder[1]|2:LIMit:UPPer <numeric_value> 309
OUTPut:RECorder[1]|2:STATe <boolean> 311
OUTPut:ROSCillator[:STATe] <boolean> 313
OUTPut:TRIGger[:STATe] <boolean> 315

xiv N1913/1914A EPM Series Power Meters Programming Guide

9 SENSe Subsystem

[SENSe] Subsystem 319
[SENSe[1]]|2|3|4:AVERage Commands 322
[SENSe[1]]|2|3|4:AVERage:COUNt <numeric_value> 323
[SENSe[1]]|2|3|4:AVERage:COUNt:AUTO <boolean> 326
[SENSe[1]]|2|3|4:AVERage:SDETect <boolean> 329
[SENSe[1]]|2|3|4:AVERage[:STATe] <boolean> 331
[SENSe[1]]|SENSe2:BUFFer:COUNt <numeric_value> 333
[SENSe[1]]|SENSe2:CORRection Commands 335
[SENSe[1]]|SENSe2:CORRection:CFACtor|GAIN[1][:INPut][:MAGNitude] <numeric_value> 336
[SENSe[1]]|SENSe2:CORRection:CSET[1]Commands 339
[SENSe[1]]|2|3|4:CORRection:CSET2 Commands 340
[SENSe[1]]|SENSe2:CORRection:CSET[1][:SELect] <string> 341
[SENSe[1]]|2|3|4:CORRection:CSET2[:SELect] <string> 343
[SENSe[1]]|SENSe2:CORRection:CSET[1]:STATe <boolean> 345
[SENSe[1]]|2|3|4:CORRection:DCYCle|GAIN3 Commands 349
[SENSe[1]]|2|3|4:CORRection:DCYCle|GAIN3[:INPut] [:MAGNitude] <numeric_value> 350
[SENSe[1]]|2|3|4:CORRection:DCYCle|GAIN3:STATe <boolean> 353
[SENSe[1]]|2|3|4:CORRection:FDOFfset|GAIN4[:INPut][:MAGNitude]? 355
[SENSe[1]]|2|3|4:CORRection:FDOFfset:UNIT <character_data> 356
[SENSe[1]]|2|3|4:CORRection:GAIN2 Commands 358
[SENSe[1]]|2|3|4:CORRection:GAIN2:STATe <boolean> 359
[SENSe[1]]|2|3|4:CORRection:GAIN2[:INPut][:MAGNitude] <numeric_value> 361
[SENSe[1]]|2|3|4:FREQuency[:CW|:FIXed] <numeric_value> 363
[SENSe[1]]|SENSe2:FREQuency[:CW|:FIXed]:STARt <numeric_value> 366
[SENSe[1]]|SENSe2:FREQuency[:CW|:FIXEd]:STEP <numeric_value> 369
[SENSe[1]]|SENSe2:FREQuency[:CW|:FIXed]:STOP <numeric_value> 372
[SENSe[1]]|2|3|4:MRATe <character_data> 375
[SENSe[1]]|2|3|4:POWer:AC:RANGe <numeric_value> 378
[SENSe[1]]|2|3|4:POWer:AC:RANGe:AUTO <boolean> 380
[SENSe[1]]|SENSe2:SPEed <numeric_value> 382
[SENSe[1]]|SENSe2:V2P ATYPe|DTYPe 385

10 STATus Subsystem

STATus Subsystem 388

N1913/1914A EPM Series Power Meters Programming Guide xv

Status Register Set Commands 390
Device Status Register Sets 395
Operation Status Register Sets 397
STATus:OPERation 398
STATus:OPERation:CALibration[:SUMMary] 399
STATus:OPERation:LLFail[:SUMMary] 400
STATus:OPERation:MEASuring[:SUMMary] 401
STATus:OPERation:SENSe[:SUMMary] 402
STATus:OPERation:TRIGger[:SUMMary] 403
STATus:OPERation:ULFail[:SUMMary] 404
STATus:PRESet 405
Questionable Status Register Sets 406
STATus:QUEStionable 407
STATus:QUEStionable:CALibration[:SUMMary] 408
STATus:QUEStionable:POWer[:SUMMary] 409

11 SYSTem Subsystem

SYSTem Subsystem 413
SYSTem:COMMunicate:GPIB[:SELF]:ADDRess <numeric_value> 415
SYSTem:COMMunicate:LAN:AIP[:STATe] <boolean> 417
SYSTem:COMMunicate:LAN:CURRent:ADDRess? 418
SYSTem:COMMunicate:LAN:CURRent:DGATeway? 419
SYSTem:COMMunicate:LAN:CURRent:DNAMe? 420
SYSTem:COMMunicate:LAN:CURRent:SMASk? 421
SYSTem:COMMunicate:LAN:ADDRess <character_data> 422
SYSTem:COMMunicate:LAN:DGATeway <character_data> 424
SYSTem:COMMunicate:LAN:DHCP[:STATe] <boolean> 426
SYSTem:COMMunicate:LAN:DNAMe <character_data> 427
SYSTem:COMMunicate:LAN:HNAMe <character_data> 429
SYSTem:COMMunicate:LAN:MAC? 431
SYSTem:COMMunicate:LAN:RESTart 432
SYSTem:COMMunicate:LAN:SMASk <character_data> 433
SYSTem:DISPlay:BMP 435
SYSTem:ERRor? 436
SYSTem:HELP:HEADers? 444

xvi N1913/1914A EPM Series Power Meters Programming Guide

SYSTem:LOCal 451
SYSTem:REMote 452
SYSTem:RWLock 453
SYSTem:VERSion? 454

12 TRIGger Subsystem

TRIGger Subsystem 458
ABORt[1]|2|3|4: 460
INITiate Commands 461
INITiate[1]|2|3|4:CONTinuous <boolean> 462
INITiate[1]|2|3|4[:IMMediate] 464
INITiate:CONTinuous:ALL <boolean> 465
INITiate:CONTinuous:SEQuence[1]|2|3|4 <boolean> 467
INITiate[:IMMediate]:ALL 469
INITiate[:IMMediate]:SEQuence[1]|2 |3|4 470
TRIGger Commands 471
TRIGger[1]|2|3|4:DELay:AUTO <boolean> 472
TRIGger[1]|2|3|4[:IMMediate] 474
TRIGger[1]|2|3|4:SOURce BUS|EXTernal|HOLD|IMMediate 475
TRIGger[:SEQuence[1]|2|3|4]:SLOPe <character_data> 478
TRIGger[:SEQuence[1]|2|3|4]:COUNt <numeric_value> 480
TRIGger[:SEQuence[1]|2|3|4]:DELay:AUTO <boolean> 482
TRIGger[:SEQuence[1]|2|3|4]:IMMediate 484
TRIGger[:SEQuence[1]|2|3|4]:SOURce BUS|EXTernal|HOLD|IMMediate 485

13 UNIT Subsystem

UNIT Subsystem 488
UNIT[1]|2|3|4:POWer <amplitude_unit> 489
UNIT[1]|2|3|4:POWer:RATio <ratio_unit> 491

14 SERVice Subsystem

SERVice Subsystem 495
SERVice:BIST:CALibrator <boolean> 505
SERVice:BIST:CW[1]|2:LINearity 507
SERVice:BIST:CW[1]|2:LINearity:PERRor? 508

N1913/1914A EPM Series Power Meters Programming Guide xvii

SERVice:BIST:CW[1]|2:ZSET 509
SERVice:CALibrator:ADJ:COUR <numeric_value> 511
SERVice:CALibrator:ADJ:FINE <numeric_value> 512
SERVice:LAN:PHOStname 521
SERVice:SECure:ERASe 522
SERVice:SENSor[1]|2:CALFactor <cal_factor_data> 523
SERVice:SENSor[1]|2|3|4:CDATe? 525
SERVice:SENSor[1]|2|3|4:CPLace? 526
SERVice:SENSor[1]|2|3|4:FREQuency:MAXimum? 527
SERVice:SENSor[1]|2|3|4:FREQuency:MINimum? 528
SERVice:SENSor[1]|2|3|4:POWer:AVERage:MAXimum? 529
SERVice:SENSor[1]|2|3|4:POWer:USABle:MAXimum? 530
SERVice:SENSor[1]|2|3|4:POWer:USABle:MINimum? 531
SERVice:SENSor[1]|2|3|4:RADC? 532
SERVice:SENSor[1]|2|3|4:TNUMber? 534
SERVice:SENSor[1]|2|3|4:TYPE? 535
SERVice:SNUMber? 536
SERVice:STATe <boolean> 537
SERVice:VERSion:PROCessor <character_data> 539
SERVice:VERSion:SYSTem <character_data> 540

15 IEEE 488.2 Command Reference

SCPI Compliance Information 542
*CLS 543
*DDT <arbitrary block program data>|<string program data> 544
*ESE <NRf> 546
*ESR? 548
*IDN? 549
*OPC 550
*OPT? 551
*RCL <NRf> 552
*RST 553
*SAV <NRf> 554
*SRE <NRf> 555
*STB? 557

xviii N1913/1914A EPM Series Power Meters Programming Guide

*TRG 559
*TST? 560
*WAI 561
GPIB Universal Commands 562

16 Programming Examples

Example 1: Identifying the EPM Series Power Meter In Use 568
Example 2: FETCh, MEASure, and READ Queries 569
Example 3: Making Repetitively Pulsed RF Power Measurement With Duty Cycle Correction 571
Example 4: CW Power Measurement 572
Example 5: Low Power Measurement 573
Example 6: Power Sweep Operation 574
Example 7: Frequency Sweep Operation 575
Example 8: Status of Various Settings 577
Example 9: Window Offset, Min/Max Hold, and Limits Settings 578

Appendix A Calibration Factor Block Layout

Calibration Factor Block Layout A-580

Appendix B Measurement Polling Example

Measurement Polling Example using VEE program B-586

Appendix C HP436A/HP437B/HP438A Command Summary

HP436A Command Summary C-590
HP437B Command Summary C-591
HP438A Command Summary C-594

N1913/1914A EPM Series Power Meters Programming Guide xix

List of Figures

Figure B-1-1 Frequency Dependent Offset Tables 28
Figure B-1-2 Typical Averaged Readings on 8480 Series Sensors 35
Figure B-1-3 Averaging Range Hysteresis 36
Figure B-1-4 Limits Checking Application 40
Figure B-1-5 Limits Checking Results 41
Figure B-1-6 How Measurement are Calculated 49
Figure B-1-7 Generalized Status Register Model 51
Figure B-1-8 Typical Status Register Bit Changes 52
Figure B-1-9 Status System 58
Figure B-1-10 Hierarchical structure of SCPI 72
Figure B-1-11 Format of <character_data> 75
Figure B-1-12 Format of <non-decimal numeric> 77
Figure B-1-13 Format of <NR1> 78
Figure B-1-14 Format of <NR2> 78
Figure B-1-15 Format of <NR3> 79
Figure B-1-16 Format of <string> 80
Figure B-2-1 Measurement Display CALCulate Block Window 88
Figure B-3-1 Measurement Display CALCulate Block Window 172
Figure B-3-2 CALCulate Block 173
Figure B-9-1 Example of Averaged Readings 326
Figure B-11-1 IEEE 488.2 Arbitrary Block Program Data Format 444
Figure B-1 Example of VEE program used in measurement polling 587

xx N1913/1914A EPM Series Power Meters Programming Guide

List of Tables

Ta bl e 1 -1 MEASure? and CONFigure Preset States 10
Ta bl e 1 -2 Possibilities of the defaulted source list parameter 15
Ta bl e 1 -3 Range of Values for Window Limits 42
Ta bl e 1 -4 Model of Sensor and Measurement Rates 45
Ta bl e 1 -5 Bit Definitions - Status Byte Register 59
Ta bl e 1 -6 Bit Definitions - Standard Event Register 60
Ta bl e 1 -7 Bit Definitions - Questionable Status Registers 62
Ta bl e 1 -8 Bit change conditions for Questionable Status Register 62
Ta bl e 1 -9 Bit Definitions - Operation Status 63
Table 1-10 Bit change conditions for Operation Status 64
Table 1-11 Bit Definitions - Device Status Register 65
Table 1-12 Bit change conditions for Device Status Register 66
Ta bl e 3 -1 Measurement Units 192
Ta bl e 3 -2 Measurement Units 195
Ta bl e 5 -1 Measurement Units 238
Ta bl e 5 -2 Measurement Units 241
Ta bl e 5 -3 Measurement Units 245
Ta bl e 5 -4 Measurement Units 248
Ta bl e 7 -1 8480 Series Power Sensor Tables 270
Ta bl e 7 -2 8480 Series Power Sensor Tables 275
Ta bl e 7 -3 Frequency and Calibration/Offset Factor List 292
Ta bl e 7 -4 Frequency and Calibration/Offset Factor List 296
Ta bl e 1 0- 1 Commands and events affecting Status Register 388
Ta bl e A- 1 Calibration Factor Block Layout: E4410 Series Sensors A-2
Ta bl e A- 2 Calibration Factor Block Layout: E9300 Series Sensors A-3
Ta bl e A- 3 Calibration Factor Block Layout: N8480 Series Sensors

N1913/1914A EPM Series Power Meters Programming Guide xxi

xxii N1913/1914A EPM Series Power Meters Programming Guide

N1913/1914A EPM Series Power Meters
Programming Guide

1
Power Meter Remote Operation

Introduction 4
Configuring the Remote Interface 5

• Interface Selection 5

• GPIB Address 5

• LAN Configuration 6

• USB Configuration 7

Zeroing and Calibrating 8

• Zeroing 8

• Calibration 9

Making Measurement 10

• Using MEASure? 11

• Using the CONFigure Command 16

• Using the Lower Level Commands 25

Using Frequency Dependent Offset Tables 27

• Overview 27

• Editing Frequency Dependent Offset Tables 29

• Selecting a Frequency Dependent Offset Table 32

• Enabling a Frequency Dependent Offset Table 32

• Making the Measurement 32

Setting the Range, Resolution and Averaging 34

• Resolution 34

• Averaging 34

• Auto Averaging Mode 35

• Filter Length 36

Range 37

Agilent Technologies

1

1 Power Meter Remote Operation

Configuring the Remote Interface 5

• Interface Selection 5

• GPIB Address 5

• LAN Configuration 6

Setting Offsets 38

• Channel Offsets 38

• Display Offsets 38

Setting Measurement Limits 40

• Setting Limits 40

• Checking for Limit Failures 42

• Using STATus 43

Getting the Best Speed Performance 44

• Measurement Rate 44

• Sensor 45

• Trigger Mode 45

• Output Format 47

• Units 47

• Command Used 47

• Fast Mode 48

How Measurements are Calculated 49

2 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Status Reporting 50

• The General Status Register Model 50

• How to Use Register 53

• The Condition Polling Method 53

• The SRQ Method 54

• Device Status Register 65

• Using the Operation Complete Commands 67

Saving and Recalling Power Meter Configurations 70

• How to Save and Recall a Configuration 70

Using Device Clear to Halt Measurements 71

An Introduction to the SCPI Language 72

• Mnemonic Forms 72

• Using a Colon (:) 72

• Using a Semicolon (;) 73

• Using a Comma (,) 73

• Using Whitespace 73

• Using “?” Commands 73

• Using “*” Commands 74

• Syntax Conventions 74

• Syntax Diagram Conventions 74

• SCPI Data Types 75

• Input Message Terminators 80

SCPI Compliance Information 82

Summary of Commands 84

This chapter describes the parameters that configure the power meter and
helps you determine settings to optimize performance.

N1913/1914A EPM Series Power Meters Programming Guide 3

1 Power Meter Remote Operation

Introduction

This chapter describes the parameters which configure the power meter
and help you determine settings to optimize performance. It contains the
following sections:

• “Configuring the Remote Interface” on page 5.

• “Zeroing and Calibrating” on page 8.

• “Making Measurement” on page 10.

• “Using Frequency Dependent Offset Tables” on page 27.

• “Setting the Range, Resolution and Averaging” on page 34.

• “Setting Offsets” on page 38.

• “Setting Measurement Limits” on page 40.

• “Getting the Best Speed Performance” on page 44.

• “How Measurements are Calculated” on page 49.

• “Status Reporting” on page 50.

• “Saving and Recalling Power Meter Configurations” on page 70.

• “Using Device Clear to Halt Measurements” on page 71.

• “An Introduction to the SCPI Language” on page 72.

• “SCPI Compliance Information” on page 82.

• “Summary of Commands” on page 84.

4 N1913/1914A EPM Series Power Meters Programming Guide

Configuring the Remote Interface

NOTE

NOTE

This section briefly describes how to configure the GPIB, LAN and USB
remote interfaces.

For more information on configuring the remote interface connectivity, refer to the Agilent
Technologies USB/LAN/GPIB Interfaces Connectivity Guide. If you have installed the IO
Libraries Suite, you can access the Connectivity Guide via the Agilent IO Libraries Control

icon. Alternatively, you can access the Connectivity Guide via the Web at
www.agilent.com/find/connectivity.

Interface Selection

You can choose to control the power meter remotely using the GPIB, LAN
or USB interfaces.

For information on selecting and configuring the remote interface
manually from the front panel, refer to the EPM Series Power Meters
Installation Guide.

Power Meter Remote Operation 1

It is expected that most users will use the front panel keys to set up the remote interfaces.
The remote interface commands are provided for completeness (for the front panel
operation).

GPIB Address

Each device on the GPIB (IEEE- 488) interface must have a unique
address. You can set the power meter’s address to any value between 0
and 30. The power meter is shipped with a default address set to 13. The
GPIB address is stored in non- volatile memory, and does not change when
the power meter is switched off, or after a remote interface reset.

Your GPIB bus controller has its own address. Avoid using the bus
controller’s address for any instrument on the interface bus. Agilent
Technologies controllers generally use address 21.

N1913/1914A EPM Series Power Meters Programming Guide 5

1 Power Meter Remote Operation

For information on setting the GPIB address manually from the front
panel, refer to the EPM Series Power Meters Installation Guide.

• To set the GPIB address from the remote interface use the:

SYSTem:COMMunicate:GPIB:ADDRess command.

• To query the GPIB address from the remote interface use the:

SYSTem:COMMunicate:GPIB:ADDRess? query.

LAN Configuration

The power meter has three LAN operating modes:

• Dynamic IP (Dynamic Host Configuration Protocol or DHCP)

• Auto IP (Local PC Control or isolated (non-site) LAN)

•Static IP (Manual mode)

These three modes can be set up from the front panel. For front panel
operation refer to the EPM Series Power Meter Installation Guide.

Configuring the LAN Remotely

To automatically configure the LAN settings, enable DHCP operation using
the SYSTem:COMMunicate:LAN:DHCP[:STATe] command.

In this Dynamic IP mode the IP Address, Subnet Mask, and Default
Gateway values are obtained from a DHCP server. Using this Dynamic IP
mode does not require a detailed knowledge of your network
configuration.

The IP Address, Subnet Mask, Default Gateway, and Host settings can be
changed manually or remotely. To individually specify the LAN settings,
use the following commands:

• IP Address -SYSTem:COMMuniucate:LAN:ADDRess

• Subnet Mask - SYSTem:COMMunicate:LAN:SMASk

• Default Gateway - SYSTem:COMMunicate:LAN:DGATeway

• Domain Name -SYSTem:COMMunicate:LAN:DNAMe

6 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

NOTE

NOTE

NOTE

NOTE

• Hostname - SYSTem:COMMunicate:LAN:HNAMe

• Restart Network -SYSTem:COMMunicate:LAN:RESTart

The character_data values for the IP address, Subnet Mask, and Default
Gateway can range between 0.0.0.0 and 255.255.255.255.

If you configure an invalid IP Address or an IP address that is used by another device or
host, an error message is generated. This error can be read by using the SYSTem:ERRor?
command.

The LAN setting values are stored in non- volatile memory and are not
part of the save- recall function.

USB Configuration

The USB interface requires no front panel or remote configuration.

The USB address cannot be changed - it is set at the factory and is
unique for each power meter.

For further information about the USB configuration refer to the EPM Series Power Meters
Installation Guide.

Before connecting the USB cable, make sure that I/O software is installed on your
computer.

For more information about Agilent IO Libraries software refer to the Connectivity Guide.

If you have installed other I/O Software, refer to documentation that accompanies the
software

N1913/1914A EPM Series Power Meters Programming Guide 7

.

1 Power Meter Remote Operation

Zeroing and Calibrating

Zeroing

Zeroing adjusts the power meter’s specified channel for a zero power
reading.

The command CALibration[1]|2|3|4:ZERO:AUTO [ONCE|ON|OFF|0|1]
causes the power meter to perform its zeroing routine on the specified
channel when enabled. This adjusts the power meter for a zero power
reading with no power supplied to the power sensor.

1|ON can only be used with a U2000 Series USB sensor. When 1|ON is
enabled the the zero is maintained by a combination of zero on- the- fly
for measurements and temperature compensation.

8 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

NOTE

Calibration

The command used to calibrate the power meter is:

CALibration[1|2]:AUTO ONCE

It is recommended that you zero the power meter before calibrating.

Calibration Sequence

This feature allows you to perform a complete calibration sequence with a
single query. The query is:

CALibration[1|2][:ALL]?

The query assumes that the power sensor is connected to the power
reference oscillator. It turns the power reference oscillator on, then after
calibrating, returns the power reference oscillator to the same state it was
in prior to the command being received. The calibration sequence consists
of:

1 Zeroing the power meter (CALibration[1|2]:ZERO:AUTO ONCE)

2 Calibrating the power meter (CALibration[1|2]:AUTO ONCE)

The query enters a number into the output buffer when the sequence is
complete. If the result is 0 the sequence was successful. If the result is 1
the sequence failed. Refer to “CALibration[1]|2|3|4[:ALL]?” on page 218
for further information.

The CALibration[1]|2|3|4[:ALL] command is identical to the
CALibration[1]|2|3|4[:ALL]? query except that no number is returned to

indicate the outcome of the sequence. You can examine the Questionable Status Register
or the error queue to discover if the sequence has passed or failed. Refer to “Status

Reporting” on page 50 for further information.

N1913/1914A EPM Series Power Meters Programming Guide 9

1 Power Meter Remote Operation

Making Measurement

The MEASure? and CONFigure commands provide a straight-forward
method to program the power meter for measurements. You can select the
measurement’s expected power level, resolution and with the N1914A the
measurement type (that is single channel, difference or ratio
measurements) all in one command. The power meter automatically
presets other measurement parameters to default values as shown in

Table 1- 1 below.

Ta b le 1 -1 MEASure? and CONFigure Preset States

Command MEASure? and CONFigure Setting

Tri g g e r so u rc e
(TRIGger:SOURce)

Filter
(SENSe:AVERage:COUNt:AUTO)

Filter
state(SENSe:AVERage:STATe)

Tri g g e r cy c le
(INITiate:CONTinuous)

Tr ig g e rD e l a y
(TRIGger:DELay:AUTO)

Immediate

On

On

Off

On

An alternative method to program the power meter is to use the lower
level commands. The advantage of using the lower level commands over
the CONFigure command is that they give you more precise control of the
power meter. As shown in Table 1- 1, the CONFigure command presets
various states in the power meter. It may be likely that you do not want
to preset these states. Refer to “Using the Lower Level Commands” on
page 25 for further information.

10 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Using MEASure?

The simplest way to program the power meter for measurements is by
using the MEASure? query. However, this command does not offer much
flexibility. When you execute the command, the power meter selects the
best settings for the requested configuration and immediately performs the
measurement. You cannot change any settings (other than the expected
power value, resolution and with the N1914A the measurement type)
before the measurement is taken. This means you cannot fine tune the
measurement, for example, you cannot change the filter length. To make
more f lexible and accurate measurements use the CONFIGure command.
The measurement results are sent to the output buffer. MEASure? is a
compound command which is equivalent to an ABORT, followed by a
CONFigure, followed by a READ?.

MEASure? Examples

The following commands show a few examples of how to use the
MEASure? query to make a measurement. It is advisable to read through
these examples in order as they become increasingly more detailed. These
examples configure the power meter for a measurement (as described in
each individual example), automatically place the power meter in the
“wait-for- trigger” state, internally trigger the power meter to take one
reading, and then sends the reading to the output buffer.

These examples give an overview of the MEASure? query. For further
information on the MEASure? commands refer to the section

“MEASure[1]|2|3|4 Commands” on page 154.

Example 1 - The Simplest Method

The following commands show the simplest method of making single
channel (for example A or B) measurements. Using MEAS1? results in an
upper window measurement, and MEAS2? in a lower window measurement.
The channel associated with the window can be set using the source list
parameter (see “Example 2 - Specifying the Source List Parameter”), or

N1913/1914A EPM Series Power Meters Programming Guide 11

1 Power Meter Remote Operation

MEAS1?

specifies window

MEAS2?

MEAS1? DEF,DEF,(@1)

specifies window

specifies channel

NOTE

defaults as in this example (see “Agilent N1914A Only” on page 14).

Example 2 - Specifying the Source List Parameter

The MEASure command has three optional parameters, an expected power
value, a resolution and a source list. These parameters must be entered in
the specified order. If parameters are omitted, they default from the right.
The parameter DEFault is used as a place holder.

The following example uses the source list parameter to specify the
measurement channel as Channel A. The expected power and resolution
parameters are defaulted, leaving them at their current settings. The
measurement is carried out on the upper window.

The operation of the MEAS1? command when the source list parameter is
defaulted is described in the note “Agilent N1914A Only” on page 14.

For the N1913A it is not necessary to specify a channel as only one channel is available.

Example 3 - Specifying the Expected Power Parameter

The previous example details the three optional parameters which can be
used with the MEASure? command. The first optional parameter is used to
enter an expected power value. Entering this parameter is only relevant if
you are using an E-Series power sensor or N8480 Series power sensor
(excluding Option CFT). The value entered determines which of the power
sensor’s two ranges is used for the measurement. If the current setting of
the power sensor’s range is no longer valid for the new measurement,
specifying the expected power value decreases the time taken to obtain a
result.

12 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

MEAS2? -50,DEF,(@2)

specifies window specifies channel

specifies expected power value

MEAS1? DEF,3

specifies window

specifies resolution setting

The following example uses the expected value parameter to specify a
value of –50 dBm. This selects the power sensor’s lower range (refer to

“Range” on page 37 for details of the range breaks). The resolution

parameter is defaulted, leaving it at its current setting. The source list
parameter specifies a Channel B measurement. The measurement is
displayed on the lower window.

Example 4 - Specifying the Resolution Parameter

The previous examples detailed the use of the expected value and source
list parameters. The resolution parameter is used to set the resolution of
the specified window. This parameter does not affect the resolution of the
data, however it does affect the auto averaging setting (refer to

Figure 1- 2).

Since the filter length used for a channel with auto- averaging enabled is
dependent on the window resolution setting, a conflict arises when a given
channel is set up in both windows and the resolution settings are
different. In this case, the higher resolution setting is used to determine
the filter length.

The following example uses the resolution parameter to specify a
resolution setting of 3. This setting represents 3 significant digits if the
measurement suffix is W or %, and 0.01 dB if the suffix is dB or dBm.

Refer to Chapter 2, “MEASurement Commands”on page 85, for further

details on the resolution parameter. The expected power and source list
parameters are defaulted in the example. The expected power value
remains unchanged at its current setting. The source list parameter

defaults as described in the note “Agilent N1914A Only” on page 14. Note

that as the source list parameter is the last specified parameter you do
not have to specify DEF. The measurement is carried out on the upper

window.

N1913/1914A EPM Series Power Meters Programming Guide 13

1 Power Meter Remote Operation

MEAS2:POW:AC:DIFF? DEF,DEF,(@2),(@1)

specifies window

specifies between which channels
the difference is calculated

Channel B - A

MEAS1:POW:AC:RAT? DEF,DEF,(@1),(@2)

specifies window

specifies the relationship of the
channels in the ratio

Channel A / B

NOTE

Example 5 - Making a Difference Measurement

The following command is performed on the N1914A. It queries the lower
window to make a difference measurement of Channel B - Channel A. The
expected power and resolution parameters are defaulted, leaving them at
their current settings.

Example 6 - Making a Ratio Measurement

The following command is performed on the N1914A. It queries the upper
window to make a ratio measurement of Channel A/B. The expected
power and resolution parameters are defaulted, leaving them at their
current settings.

Agilent N1914A Only

The operation of the MEASure? command when the source list parameter is defaulted
depends on the current setup of the window concerned (for example, A, B, A/B, A-B etc.)
and on the particular command used (for example, MEAS[:POW][:AC]? and
MEAS:POW:AC:RAT?).

This means that when the source list parameter is defaulted, there are a number of
possibilities.

14 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Ta b le 1 -2 Possibilities of the defaulted source list parameter

Command Current Window Setup Measurement

MEAS1[:POW][AC]? Upper Window: A A

BB

Any Other Any Other A

MEAS2[:POW][AC]? Lower Window: A A

BB

Any Other B

MEAS1:POW:AC:RAT Upper Window: A/B A/B

B/A B/A

Any Other A/B

MEAS2:POW:AC:RAT Lower Window: A/B A/B

B/A B/A

Any Other A/B

MEAS1:POW:AC:DIFF? Upper Window: A-B A-B

B-A B-A

Any Other A-B

MEAS2:POW:AC:DIFF? Lower Window: A-B A-B

B-A B-A

Any Other A-B

N1913/1914A EPM Series Power Meters Programming Guide 15

1 Power Meter Remote Operation

Using the CONFigure Command

When you execute this command, the power meter presets the optimum
settings for the requested configuration (like the MEASure? query).
However, the measurement is not automatically started and you can
change measurement parameters before making measurements. This allows
you to change the power meter’s configuration from the preset conditions.
The power meter offers a variety of low-level commands in the SENSe,
CALCulate, and TRIGger subsystems. For example, if you want to change
the averaging use the [SENSe[1]]|SENSe2:AVERage:COUNt command.

Use the INITiate or READ? query to initiate the measurement.

Using READ?

CONFigure does not take the measurement. One method of obtaining a
result is to use the READ? query. The READ? query takes the measurement
using the parameters set by the CONFigure command then sends the
reading to the output buffer. Using the READ? query obtains new data.

Using INITiate and FETCh?

CONFigure does not take the measurement. One method of obtaining the

result is to use the INITiate and FETCh? commands. The INITiate
command causes the measurement to be taken. The FETCh? query
retrieves a reading when the measurement is complete, and sends the
reading to the output buffer. FETCh? can be used to display the
measurement results in a number of different formats (for example, A/B
and B/A) without taking fresh data for each measurement.

CONFigure Examples

The following program segments show how to use the commands READ?,
INITiate and FETCh? and CONFigure to make measurements.

It is advisable to read through these examples in order as they become
increasingly more detailed.

These examples give an overview of the CONFigure command. For further
information on the CONFigure commands refer to Chapter 2,
“MEASurement Commands”.

16 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Example 1 - The Simplest Method

The following program segments show the simplest method of querying the
upper and lower window’s measurement results respectively.

Using READ?

*RST Reset instrument
CONF1 Configure upper window - defaults to a Channel A

measurement

READ1? Take upper window (Channel A) measurement

*RST Reset instrument

CONF2 Configure lower window - defaults to a Channel A (N1913A),

Channel B (N1914A) measurement

READ2? Take lower window measurement (Channel A on N1913A, B

on N1914A)

Using INITiate and FETCh?

*RST Reset instrument

CONF1 Configure upper window - defaults to a Channel A

measurement

INIT1? Causes Channel A to make a measurement

FETC1? Retrieves the upper window’s measurement

For the N1913A only:

*RST Reset instrument

CONF2 Configure lower window - N1913A defaults to Channel A
INIT1 Causes Channel A to make a measurement

FETC2? Retrieves the lower window’s measurement

For the N1914A only:

*RST Reset instrument

CONF2 Configure lower window
INIT2? Causes Channel B to make a measurement

N1913/1914A EPM Series Power Meters Programming Guide 17

1 Power Meter Remote Operation

NOTE

FETC2? Retrieves the lower window’s measurement

Example 2 - Specifying the Source List Parameter

The CONFigure and READ? commands have three optional parameters, an
expected power value, a resolution and a source list. These parameters
must be entered in the specified order. If parameters are omitted, they
default from the right. The parameter DEFault is used as a place holder.

The following examples use the source list parameter to specify the
measurement channel as Channel A. The expected power and resolution
parameters are defaulted, leaving them at their current settings. The
measurement is carried out on the upper window.

Although the READ? and FETCh? queries have three optional parameters it
is not necessary to define them as shown in these examples. If they are
defined they must be identical to those defined in the CONFigure
command otherwise an error occurs.

For the N1913A it is not necessary to specify a channel as only one channel is available.

Using READ?

ABOR1 Aborts Channel A
CONF1 DEF,DEF,(@1) Configures the upper window to make a

Channel A measurement using the current
expected power and resolution settings

READ1? Takes the upper window’s measurement

18 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Using INITiate and FETCh?

ABOR1 Aborts Channel A

CONF1 DEF,DEF,(@1) Configures the upper window to make a

Channel A measurement using the current
expected power and resolution settings

INIT1 Causes Channel A to make a measurement

FETC1? DEF,DEF,(@1) Retrieves the upper window’s

measurement

Example 3 - Specifying the Expected Power Parameter

The previous example details the three optional parameters which can be
used with the CONFigure and READ? commands. The first optional
parameter is used to enter an expected power value. Entering this
parameter is only relevant if you are using an E- Series power sensor or
N8480 Series power sensor (excluding Option CFT). The value entered
determines which of the power sensor’s two ranges is used for the
measurement. If the current setting of the power sensor’s range is no
longer valid for the new measurement, specifying the expected power
value decreases the time taken to obtain a result.

The following example uses the expected value parameter to specify a
value of –50 dBm. This selects the power meter’s lower range (refer to

“Range” on page 37 for details of the range breaks). The resolution

parameter is defaulted, leaving it at its current setting. The source list
parameter specifies a Channel B measurement. The measurement is
carried out on the upper window.

N1913/1914A EPM Series Power Meters Programming Guide 19

1 Power Meter Remote Operation

Using READ?

ABOR2 Aborts Channel B

CONF1 -50,DEF,(@2) Configures the upper window to make a

READ1? Takes the upper window’s measurement

Some fine tuning of measurements can be performed using the CONFigure
and READ? commands. For example, in the above program segment some
fine tuning can be performed by setting the filter length to 1024 and the
trigger delay off.

1 ABOR2

2 CONF1 -50,DEF,(@2)

3 SENS2:AVER:COUN 1024

4 TRIG2:DEL:AUTO OFF

5 READ1?

Channel B measurement using an expected
power of –50 dBm and the current resolution
setting

Using INITiate and FETCh?

ABOR2 Aborts Channel B
CONF1 -50,DEF,(@2) Configures the upper window to make a

Channel B measurement using an expected
power of –50 dBm and the current resolution
setting

INIT2 Causes Channel B to make a measurement
FETC1? -50,DEF,(@2) Retrieves the upper window’s measurement

Some fine tuning of measurements can be carried out using the
CONFigure command and INITiate and FETCh? commands. For example,
in the above program segment some fine tuning can be carried out by

20 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

setting the filter length to 1024 and the trigger delay off.

1 ABOR2

2 CONF1 -50,DEF,(@2)

3 SENS2:AVER:COUN 1024

4 TRIG2:DEL:AUTO OFF

5 INIT2

6 FETC1? -50,DEF,(@2)

Example 4 - Specifying the Resolution Parameter

The previous examples detailed the use of the expected value and source
list parameters. The resolution parameter is used to set the resolution of
the specified window. This parameter does not affect the resolution of the
data, however it does affect the auto averaging setting (refer to Figure 1- 2
on page 35).

Since the filter length used for a channel with auto- averaging enabled is
dependent on the window resolution setting, a conflict arises when a given
channel is set up in both windows and the resolution settings are
different. In this case, the higher resolution setting is used to determine
the filter length.

The following example uses the resolution parameter to specify a
resolution setting of 3. This setting represents 3 significant digits if the
measurement suffix is W or %, and 0.01 dB if the suffix is dB or dBm (for
further details on the resolution parameter refer to the commands in

Chapter 2, “MEASurement Commands”). Also, in this example the

expected power and source list parameters are defaulted. The expected
power value is left unchanged at its current setting. The source list
parameter is defaulted as described in the note “Agilent N1914A Only” on
page 14. Note that as the source list parameter is the last specified
parameter you do not have to specify DEF.

N1913/1914A EPM Series Power Meters Programming Guide 21

1 Power Meter Remote Operation

Using READ?

ABOR1 Aborts Channel A

CONF1 DEF,3 Configures the upper window to make a measurement

READ1? Takes the upper window’s measurement. This is

Some fine tuning of the above program segment can be carried out for
example, by setting the trigger delay off. The following program segment
assumes that Channel A is currently being measured on the upper
window.

1 ABOR1

2 CONF1 DEF,3

3 TRIG1:DEL:AUTO OFF

4 READ1?

using the current setting of the expected power and
source list and a resolution setting of 3

Channel A or B measurement depending on current
window setup.

Using INITiate and FETCh?

The following program segment assumes that Channel A is currently being
measured on the upper window.

ABOR1 Aborts Channel A

CONF1 DEF,3 Configures the upper window to make a

measurement using the current setting of the
expected power and source list and a resolution
setting of 3

INIT1 Causes Channel A to make a measurement

FETC1? DEF,3 Retrieves the upper window’s measurement

Some fine tuning of the above program segment can be carried out for
example, by setting the trigger delay off.

1 ABOR1

2 CONF1 DEF,3

22 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

3 TRIG1:DEL:AUTO OFF

4 INIT1:IMM

5 FETC1? DEF,3

Example 5 - Making a Difference Measurement

The following program segment can be carried out on the N1914A. It
queries the lower window to make a difference measurement of
Channel A - Channel B. The expected power level and resolution
parameters are defaulted, leaving them at their current settings. Some fine
tuning of the measurement is carried out by setting the averaging, and the
trigger delay to off.

Using READ?

ABOR1
ABOR2
CONF2:POW:AC:DIFF DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 1024
SENS2:AVER:COUN 1024
TRIG1:DEL:AUTO OFF
TRIG2:DEL:AUTO OFF
READ2:POW:AC:DIFF?

READ2:POW:AC:DIFF? DEF,DEF,(@2),(@1) (A second READ? query is sent

to make a Channel B - Channel A measurement using fresh measurement
data).

Using INITiate and FETCh?

ABOR1
ABOR2
CONF2:POW:AC:DIFF DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 1024
SENS2:AVER:COUN 1024
TRIG1:DEL:AUTO OFF
TRIG2:DEL:AUTO OFF
INIT1:IMM
INIT2:IMM
FETC2:POW:AC:DIFF?

N1913/1914A EPM Series Power Meters Programming Guide 23

1 Power Meter Remote Operation

FETC2:POW:AC:DIFF? DEF,DEF,(@2),(@1) (A second FETCh? query is sent
to make a Channel B - Channel A measurement using the current
measurement data).

Example 6 - Making a Ratio Measurement

The following program segment can be carried out on the N1914A. It
queries the lower window to make a ratio measurement of Channel A/B.
The expected power level and resolution parameters are defaulted, leaving
them at their current settings. Some fine tuning of the measurement is
carried out by setting the averaging.

Using READ?

ABOR1
ABOR2
CONF2:POW:AC:RAT DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 512
SENS2:AVER:COUN 256
READ2:POW:AC:RAT?

READ2:POW:AC:RAT? DEF,DEF,(@2),(@1) (A second R EAD? query is sent to

make a Channel B - Channel A ratio measurement using fresh measurement
data.)

Using INITiate and FETCh?

ABOR1
ABOR2
CONF2:POW:AC:RAT DEF,DEF,(@1),(@2)
SENS1:AVER:COUN 512
SENS2:AVER:COUN 256
INIT1:IMM
INIT2:IMM
FETC2:POW:AC:RAT?

FETC2:POW:AC:RAT? DEF,DEF,(@2),(@1) (A second FETCh? query is sent to

make a Channel B - Channel A measurement using the current measurement
data.)

24 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Using the Lower Level Commands

An alternative method of making measurements is to use the lower level
commands to set up the expected range and resolution. This can be done
using the following commands:

[SENSe[1]]|SENSe2:POWER:AC:RANGe
DISPlay[:WINDow[1|2]]:RESolution

The measurement type can be set using the following commands in the

CALCulate subsystem:

CALCulate[1|2]:MATH[:EXPRession]
CALCulate[1|2]:RELative[:MAGNitude]

The advantage of using the lower level commands over the CONFigure
command is that they give you more precise control of the power meter.
As shown in Table 1- 1 the CONFigure command presets various states in
the power meter. It may be likely that you do not want to preset these
states.

Example

The following example sets the expected power value to –50 dBm and the
resolution setting to 3 using the lower level commands. The measurement
is a single Channel A measurement carried out on the lower window.

ABOR1 Aborts Channel A
CALC2:MATH:EXPR

"(SENS1)"

SENS1:POW:AC:RANGE 0 Sets lower range (E- Series sensors and

DISP:WIND2:RES 3 Sets the lower window’s resolution to setting

INIT1 Causes Channel A to make a measurement

N1913/1914A EPM Series Power Meters Programming Guide 25

Displays Channel A on lower window

N8480 Series sensors (excluding Option
CFT) only)

3

1 Power Meter Remote Operation

FETC2? Retrieves the lower window’s measurement

26 N1913/1914A EPM Series Power Meters Programming Guide

Using Frequency Dependent Offset Tables

This section describes how to use frequency dependent offset tables. These
tables give you the ability to compensate for frequency effects in your test
setup.

Overview

If the [SENSe[1]]|SENSe2:CORRection:CSET2:STATe command is OFF,
the frequency dependent offset tables are not used. When
[SENSe[1]]|SENSe2:CORRection:CSET2:STATe is ON, the frequency
dependent offset tables are used, providing you with a quick and
convenient method of compensating for your external test setup over a
range of frequencies. Note that when selected, frequency dependent offset
correction is IN ADDITION to any correction applied for sensor frequency
response. The power meter is capable of storing 10 frequency dependent
offset tables of 80 frequency points each.

To use frequency dependent offset tables you:

Power Meter Remote Operation 1

1 Edit a frequency dependent offset table if necessary.

2 Select the frequency dependent offset table.

3 Enable the frequency dependent offset table.

4 Zero and calibrate the power meter.

If you are using an 8480 Series sensors or N8480 Series sensor with
Option CFT, the reference calibration factor used during the calibration
must be entered manually.

5 Specify the frequency of the signal you want to measure. The required

offset is automatically set by the power meter from the frequency
dependent offset table.

6 Make the measurement.

Figure 1- 1 illustrates how frequency dependent offset tables operate.

N1913/1914A EPM Series Power Meters Programming Guide 27

1 Power Meter Remote Operation

TABLE N

FREQ

FREQ

1

.
.
.
.
.
.
.
.
.

.

.

FREQ

2

80

OFFSET

OFFSET

1

.
.
.
.
.
.
.
.
.

.

.

80

TABLE 1

FREQ

FREQ

1

.
.
.
.
.
.
.
.
.

.

.

FREQ

2

80

OFFSET

OFFSET

1

.
.
.
.
.
.
.
.
.

.

.

2

80

TABLE 10

FREQ

FREQ

1

.
.
.
.
.
.
.
.
.

.

.

FREQ

2

80

OFFSET

OFFSET

1

.
.
.
.
.
.
.
.
.

.

.

OFFSET

2

80

OFFSET = Frequency Dependent Offset

FREQ

FREQ

1

.
.
.
.
.
.
.
.
.

.

.

FREQ

2

80

OFFSET

OFFSET

1

.
.
.
.
.
.
.
.
.

.

.

OFFSET

2

80

Frequen cy of the signal you want
to measu re

TABLE SELECTED

OFFSET

2

OFFSET

Frequency dependent
offset used to make
Measurement. Calculated
by the power meter using
linear interpolation.

28 N1913/1914A EPM Series Power Meters Programming Guide

Figure 1-1 Frequency Dependent Offset Tables

Power Meter Remote Operation 1

Editing Frequency Dependent Offset Tables

It is not possible to create any additional frequency dependent offset
tables. However, the 10 existing tables can be edited using the MEMory
subsystem. To do this:

1 Select one of the existing tables using:

MEMory:TABle:SELect <string>

For information on naming frequency dependent offset tables see

“Naming Frequency Dependent Offset Tables” on page 31. For

information on the current names which you can select refer to “Listing

the Frequency Dependent Offset Table Names” on page 30.

2 Enter the frequency data using:

MEMory:TABle:FREQuency <numeric_value> {,<numeric_value>}

3 Enter the offset factors as shown in the table below using:

MEMory:TABle:GAIN <numeric_value> {,<numeric_value>}

Frequency Offset

Frequency 1 Offset 1

Frequency 2 Offset 2

""

Frequency n Offset n

4 If required, rename the frequency dependent offset table using:

MEMory:TABLe:MOVE <string>,<string>. The first <string> parameter
identifies the existing table name, and the second identifies the new
table name.

N1913/1914A EPM Series Power Meters Programming Guide 29

1 Power Meter Remote Operation

NOTE

The legal frequency suffix multipliers are any of the IEEE suffix multipliers, for example,
KHZ, MHZ, and GHZ. If no units are specified the power meter assumes the data is Hz.

PCT is the only legal unit for offset factors and can be omitted.

The frequency and offset data must be within range. Refer to the individual commands in

Chapter 4 for their specified ranges.

Any offset values entered into the table should exclude the effect of the sensor.
Characterization of the test setup independently of the sensor allows the same table to be
used with any sensor.

Ensure that the frequency points you use cover the frequency range of the signals you want
to measure. If you measure a signal with a frequency outside the frequency range defined
in the frequency dependent offset table, then the power meter uses the highest or lowest
frequency point in the table to calculate the offset.

To make subsequent editing of a frequency dependent offset table simpler, it is
recommended that you retain a copy of your data in a program.

Listing the Frequency Dependent Offset Table Names

To list the frequency dependent offset tables currently stored in the power
meter, use the following command:

MEMory:CATalog:TABLe?

Note that all tables are listed; including sensor calibration tables.

The power meter returns the data in the form of two numeric parameters
and a string list representing all stored tables.

• <numeric_value>,<numeric_value>{,<string>}

The first numeric parameter indicates the amount of memory, in bytes,
used for storage of tables. The second parameter indicates the memory,
in bytes, available for tables.

Each string parameter returned indicates the name, type and size of a
stored frequency dependent offset table:

• <string>,<type>,<size>

The <string>, <type> and <size> are all character data. The <type> is

always TABL. The <size> is displayed in bytes.

For example, a sample of the response may look like:

30 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

560,8020,“Offset_1,TABL,220”,”Offset_2,TABL,340” ....

Naming Frequency Dependent Offset Tables

To rename a frequency dependent offset table use:

MEMory:TABLe:MOVE <string>,<string>

The first <string> parameter identifies the existing table name, and the
second identifies the new table name.

The following rules apply to frequency dependent offset table names:

1 Table names use a maximum of 12 characters.

2 All characters must be upper or lower case alphabetic characters, or

numeric (0- 9), or an underscore (_).

No spaces are allowed in the name.

Reviewing Table Data

To review the data stored in a frequency dependent offset table, use the
following commands:

MEMory:TABLe:SELect "Offset1"

Select the sensor calibration table named “Offset1”.

MEMory:TABLe:SELect?

Query command which returns the name of the currently selected table.

MEMory:TABLe:FREQuency:POINTs?

Query command which returns the number of stored frequency points.

MEMory:TABLe:FREQuency?

Query command which returns the frequencies stored in the frequency
dependent offset table (in Hz).

MEMory:TABLe:GAIN[:MAGNitude]:POINTs?

Query command which returns the number of offset factor points stored in
the frequency dependent offset table.

MEMory:TABLe:GAIN[:MAGNitude]?

Query command which returns the offset factors stored in the frequency
dependent offset table.

Modifying Data

If you need to modify the frequency and offset factor data stored in a
frequency dependent offset table you need to resend the complete data
lists.

N1913/1914A EPM Series Power Meters Programming Guide 31

1 Power Meter Remote Operation

If you have retained the original data in a program, edit the program and
resend the data.

Selecting a Frequency Dependent Offset Table

After you have created the frequency dependent offset table, you can
select it using the following command:

[SENSe[1]]|SENSe2:CORRection:CSET2[:SELect] <string>

To find out which frequency dependent offset table is currently selected,
use the query:

[SENSe[1]]|SENSe2:CORRection:CSET2[:SELect]?

Enabling a Frequency Dependent Offset Table

To enable the frequency dependent offset table, use the following
command:

[SENSe[1]]|SENSe2:CORRection:CSET2:STATe ON

If you set [SENSe[1]]|SENSe2:CORRection:CSET2:STATe to ON and no
frequency dependent offset table is selected error –221, “Settings conflict”
occurs.

Making the Measurement

To make the power measurement, set the power meter for the frequency of
the signal you want to measure. The power meter automatically sets the
calibration factor. Use either the INITiate, FETCh? or the READ? query to
initiate the measurement as shown in the following program segments:

INITiate Example

ABORt1
CONFigure1:POWer:AC DEF,1,(@1)
SENS1:CORR:CSET2:SEL "Offset1"

32 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

NOTE

SENS1:CORR:CSET2:STAT ON
SENSe1:FREQuency 500KHZ
INITiate1:IMMediate
FETCh1?

READ? Example

ABORt1
CONFigure1:POWer:AC DEF,2,(@1)
SENS1:CORR:CSET2:SEL "Offset1"
SENS1:CORR:CSET2:STAT ON
SENSe1:FREQuency 500KHZ
READ1?

If the measurement frequency does not correspond directly to a frequency in the frequency
dependent offset table, the power meter calculates the offset using linear interpolation.

If you enter a frequency outside the frequency range defined in the frequency dependent
offset table, then the power meter uses the highest or lowest frequency point in the table to
set the offset.

To find out the value of the offset being used by the power meter to make a measurement,
use the query command:

SENSe:CORRection:GAIN4|FDOFfset[:INPut][MAGNITUDE]?

The response may be an interpolated value.

N1913/1914A EPM Series Power Meters Programming Guide 33

1 Power Meter Remote Operation

Setting the Range, Resolution and Averaging

This section provides an overview of setting the range, resolution and
averaging. For more detailed information about these features refer to the
individual commands in Chapter 9, “SENSe Subsystem”.

Resolution

You can set the window’s resolution using the following command:

DISPlay[:WINDow[1]|2][:NUMeric[1]|2]
:RESolution <numeric_value>

There are four levels of resolution available (1 through 4).

When the measurement suffix is W or % this parameter represents the
number of significant digits. When the measurement suffix is dB or dBM,
1 through 4 represents 1, 0.1, 0.01, and 0.001 dB respectively.

Refer to the :RESolution command on page 251 for further information.

Averaging

The power meter has a digital filter to average power readings. The
number of readings averaged can range from 1 to 1024. This filter is used
to reduce noise, obtain the desired resolution and to reduce the jitter in
the measurement results. However, the time to take the measurement is
increased. You can select the filter length or you can set the power meter
to auto filter mode. To enable and disable averaging use the following
command:

[SENSe[1]]|SENSe2:AVERage[:STATe] <boolean>

34 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

NOTE

10 dB

10 dB

Minimum Sensor Power

Maximum Sensor Power

Power Sensor

Dynamic Range

10 dB

10 dB

1234

8 8 128 128

Resolution Setting

Number of Averages

1 1 16 256

11232

11116

1118

Auto Averaging Mode

To enable and disable auto filter mode, use the following command:

[SENSe[1]]|SENSe2:AVERage:COUNt:AUTO <boolean>

When the auto filter mode is enabled, the power meter automatically sets
the number of readings averaged together to satisfy the filtering
requirements for most power measurements. The number of readings
averaged together depends on the resolution and the power level currently
being measured. Figure 1- 2 lists the number of readings averaged for each
range and resolution when the power meter is in auto filter mode.

Figure 1-2 applies to 8480 Series only.

N1913/1914A EPM Series Power Meters Programming Guide 35

Figure 1-2 Typical Averaged Readings on 8480 Series Sensors

Figure 1- 3 illustrates part of the power sensor dynamic range hysteresis.

1 Power Meter Remote Operation

Minimum Sensor Power Minimum Sensor Power + 10 dB

Range Hysteresis

10.5 dB9.5 dB

Figure 1-3 Averaging Range Hysteresis

Filter Length

You specify the filter length using the following command:

[SENSe[1]]|SENSe2:AVERage:COUNt <numeric_value>

The range of values for the filter length is 1 to 1024. Specifying this
command disables automatic filter length selection. Increasing the value of
the filter length reduces measurement noise. However, the time to take the
measurement is increased.

36 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Range

The power meter has no internal ranges which can be set. The only ranges
that can be set are those of the E-Series power sensor and N8480 Series
power sensors (excluding Option CFT). With an E- Series power sensor or
N8480 Series power sensors (excluding Option CFT), the range can be set
either automatically or manually. Use autoranging when you are not sure
of the power level you will be measuring.

Setting the Range

To set the range manually use the following command:

[SENSe[1]]|SENSe2:POWer:AC:RANGe <numeric_value>

If the <numeric_value> is set to:

• 0, the sensor’s lower range is selected. (For example, this range is –70
to –13.5 dBm for the E4412A power sensor.)

• 1, the sensor’s upper range is selected. (For example, this range is
–14.5 to +20 dBm for the E4412A power sensor.)

For details on the range limits of other E- Series power sensor and N8480
Series power sensor (excluding Option CFT), refer to the appropriate
power sensor manual.

For further information on this command refer to page 378.

To enable autoranging use the following command:

[SENSe[1]]|SENSe2:POWer:AC:RANGe:AUTO ON

Use autoranging when you are not sure of the power level you will be
measuring.

N1913/1914A EPM Series Power Meters Programming Guide 37

1 Power Meter Remote Operation

Loss

1

Gain

------------ -

=

Gain Loss–=

NOTE

Setting Offsets

Channel Offsets

The power meter can be configured to compensate for signal loss or gain
in your test setup (for example, to compensate for the loss of a 10 dB
attenuator). You use the SENSe command subsystem to configure the
power meter. Gain and loss correction are a coupled system. This means
that a gain set by [SENSe[1]]|SENSe2:CORRection:GAIN2 is represented
in the [SENSe[1]]|SENSe2:CORRection:LOSS2? command. If you enter an
offset value the state is automatically enabled. However it can be enabled
and disabled using either the

[SENSe[1]]|SENSe2:CORRection:GAIN2:STATe or
[SENSe[1]]|SENSe2:CORRection:LOSS2:STATe commands.

LOSS2 is coupled to GAIN2 by the equation when the default

unit

is linear, and when the default is logarithmic.

You can only use LOSS2 and GAIN2 for external losses and gains. LOSS1 and GAIN1 are
specifically for calibration factors.

Display Offsets

Display offset values can be entered using the

CALCulate[1|2]:GAIN[:MAGNitude] command.
CALCulate[1|2]:GAIN:STATe must be set to ON to enable the offset

value. If you enter an offset value the state is automatically enabled. This
offset is applied after any math calculations (refer to Figure 1- 6 on
page 49).

Example

The following example program, in HP Basic, details how to use the
channel and display offsets on an N1914A making a Channel A/B ratio
measurement.

38 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

A

dBm

10–

B

dBm

10–

------------------------ -

⎝⎠

⎛⎞

20–

⎝⎠

⎛⎞

dB

The final result is:

10 !Create I/O path name
20 ASSIGN @POWER TO 713
30 !Clear the power meter’s interface
40 CLEAR @POWER
50 !Set the power meter to a known state
60 OUTPUT @POWER;"*RST"
70 !Configure the Power Meter to make the measurement
80 OUTPUT @Power;"CONF:POW:AC:RAT 20DBM,2,(@1),(@2)"
90 !Set the measurement units to dBm
100 OUTPUT @POWER;"UNIT:POW DBM"
110 !Set the power meter for channel offsets of -10 dB
120 OUTPUT @POWER;"SENS1:CORR:GAIN2 -10"
130 OUTPUT @POWER;"SENS2:CORR:GAIN2 -10"
140 !Enable the gain correction
150 OUTPUT @POWER;"SENS:CORR:GAIN2:STATe ON"
160 OUTPUT @POWER;"SENS2:CORR:GAIN2:STATe ON"
170 !Set the power meter for a display offset of -20 dB
180 OUTPUT @POWER;"CALC1:GAIN -20 DB"
190 PRINT "MAKING THE MEASUREMENT"
200 !Initiate the measurement
210 OUTPUT @Power;"INIT1:IMM"
220 OUTPUT @Power;"INIT2:IMM"
230 ! ... and get the result
240 OUTPUT @Power;"FETC:POW:AC:RAT? 20DBM,2,(@1),(@2)"
250 ENTER @Power;Reading
260 !
270 PRINT "The measurement result is ";Reading;"dB."
280 END

For further information on channel offsets refer to page 355. For further
information on display offsets refer to page 180.

N1913/1914A EPM Series Power Meters Programming Guide 39

1 Power Meter Remote Operation

Power Meter

Swept Source

CHANNEL A

INPUT

OUT

IN OUT

Device
Under Test

Setting Measurement Limits

You can configure the power meter to detect when a measurement is
outside of a predefined upper and/or lower limit value.

Limits are window or measurement display line based and can be applied
to power, ratio or difference measurements.

Setting Limits

The power meter can be configured to verify the power being measured
against an upper and/or lower limit value. The range of values that can be
set for lower and upper limits is –150.00 dBm to +230.00 dBm. The
default upper limit is +90.00 dBm and the default lower limit is
–90.00 dBm.

A typical application for this feature is shown in Figure 1- 4.

Figure 1-4 Limits Checking Application

40 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

+4 dBm

+10 dBm

Amplitude

Frequency

o

o

o

o

o

o

o

Fail

Fail

Figure 1-5 Limits Checking Results

The range of values that can be set for the upper and lower limits and the
default values depends on the measurement units in the currently
measurement line - see Table 1- 3.

N1913/1914A EPM Series Power Meters Programming Guide 41

1 Power Meter Remote Operation

Ta b le 1 -3 Range of Values for Window Limits

Window
Units

dB +200 dB

dBm +230 dBm

% 999.9 X% 100.0 a% 100.0 M% 100.0 p%

W 100.000 XW 1.000 aW 1.000 MW 1.000 pW

Maximum Minimum Maximum Minimum

–180 dB

–150 dBm

60 dB

90 dBm

Default

–120 dB

–90 dBm

Checking for Limit Failures

There are two ways to check for limit failures:

1 Use the SENSe:LIMit:FAIL? and SENSe:LIMit:FCOunt? commands

for channel limits or the

CALCulate[1|2]:LIMit:FAIL? and the
CALCulate[1|2]:LIMit:FCOunt? for window limits

2 Use the STATus command subsystem

Using SENSe and CALCulate

Using SENSe to check the channel limit failures in Figure 1- 5 would
return the following results:

SENSe:LIMit:FAIL? Returns 1 if there has been 1 or

more limit failures or 0 if there
have been no limit failures. In this
case 1 is returned.

SENSe:LIMit:FCOunt? Returns the total number of limit

failures, in this case 2.

Use the equivalent CALCulate commands for checking window limit
failures.

42 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

NOTE

If TRIGger:DELay:AUTO is set to ON, then the number of failures returned by
SENSe:LIMit:FCOunt? or CALCulate[1|2]:LIMit:FCOunt? is affected by the

current filter settings.

Using STATus

If using GPIB, you can use the STATus subsystem to generate an SRQ to
interrupt your program when a limit failure occurs. This is a more
efficient method than using SENSe or CALCulate, since you do not need
to check the limit failures after every power measurement.

Refer to “Status Reporting” on page 50 and “STATus Subsystem” on
page 387 for further information.

N1913/1914A EPM Series Power Meters Programming Guide 43

1 Power Meter Remote Operation

Getting the Best Speed Performance

This section discusses the factors that influence the speed of operation
(number of readings/sec) of a EPM Series power meter.

The following factors are those which have the greatest effect upon
measurement speed (in no particular order):

• The selected measurement rate, i.e. NORMal, DOUBle, FAST.

•The sensor being used.

• The trigger mode (for example, free run, trigger with delay etc.).

•The output format: ASCii or REAL.

• The units used for the measurement.

• The command used to take a measurement.

In addition, in FAST mode there are other influences which are described
in “Fast Mode” on page 48.

The following paragraphs give a brief description of the above factors and
how they are controlled from SCPI.

Measurement Rate

There are three possible speed settings NORMal, DOUBle and FAST. These
are set using the SENSe:MRATe command and can be applied to each
channel independently.

In NORMal and DOUBle modes, full instrument functionality is available
and these settings can be used with all sensors. FAST mode is only
available for the E- Series sensors. Also, in FAST mode averaging, limits
and ratio/difference math functions are disabled.

Refer to “Specifications” in the EPM Series Power Meters User’s Guide to
see the influence of these speed settings on the accuracy and noise
performance of the power meter.

44 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Sensor

Different measurement rates are achievable depending on the sensor type
being used, as shown in Table 1- 4:

Ta b le 1 -4 Model of Sensor and Measurement Rates

Sensor Measurement Rate

NORMal DOUBle FAST

8480 Series and N8480 Series 20 reading/s 40 reading/s NA

E-Series E4410 and E9300 50 ms

20 reading/s

U2000 Series 20 reading/s 40 reading/s Up to 110

25 ms

40 reading/s

Up to 400

readings/s

Tri gg er Mo de

The power meter has a very flexible triggering system. For simplicity, it
can be described as having three modes:

•Free Run: When a channel is in Free Run, it continuously takes
measurements on this channel. A channel is in free run when

INITiate:CONTinuous is set to ON and TRIGger:SOURce is set to
IMMediate.

• Triggered Free Run: When a channel is in Triggered Free Run

Continuous Trigger, it takes a new measurement each time a trigger
event is detected. A channel is in Triggered Free Run Continuous
Trigger when INITiate:CONTinuous is set to ON and TRIGger:SOURce
is not set to IMMediate.

• Single Shot: When a channel is in Single Shot, it takes a new

measurement when a trigger event is detected and then returns to the
idle state. A channel is in Single Shot when INITiate:CONTinuous is
set to OFF. Note that a measurement can take several INT/EXT triggers
depending on the filter settings. Refer to

“TRIGger[1]|2|3|4:DELay:AUTO <boolean>” on page 472 for further

information.

N1913/1914A EPM Series Power Meters Programming Guide 45

1 Power Meter Remote Operation

NOTE

A trigger event can be any of the following:

• The input signal meeting the trigger level criteria.

• Auto-level triggering being used.

•A TRIGger GET or *TRG command being sent.

• An external TTL level trigger being detected.

Trigger with Delay

This can be achieved using the same sequences above (apart from the
second) with TRIG:DEL:AUTO set to ON. Also, the MEAS? command
operates in trigger with delay mode.

In trigger with delay mode, a measurement is not completed until the
power meter filter is full. In this way, the reading returned is guaranteed
to be settled. In all other modes, the result returned is simply the current
result from the filter and may or may not be settled. This depends on the
current length of the filter and the number of readings that have been
taken since a change in power level.

With trigger with delay enabled, the measurement speed can be calculated
roughly using the following equation:

readings/sec = speed (as set by SENSe:SPEed) / filter length

For example, with a filter length of 4 and SENS:SPE set to 20,
approximately 5 readings/sec is calculated by the power meter.

Typically, free run mode provides the best speed performance from the
power meter (especially in 200 readings/sec mode).

46 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Output Format

The power meter has two output formats for measurement results: ASCii
and REAL. These formats are selected using the FORMat command. When
FORMat is set to REAL, the returned result is in IEEE 754 floating-point
format (note that the byte order can be changed using FORMat:BORDer)
plus <LF> as an end sentinel of the block.

The REAL format is likely to be required only for FAST mode as it reduces
the amount of bus traffic.

Units

The power meter can output results in either linear or log units. The
internal units are linear, therefore optimal performance is achieved when
the results output are also in linear units (since the overhead of
performing a log function is removed).

Command Used

In Free Run mode, FETCh? must be used to return a result.

In other trigger modes, there are a number of commands which can be
used, for example, MEASure?, READ?, FETCh? Note that the MEAS? and
READ? commands are compound commands—they perform a combination
of other lower level commands. Typically, the best speed performance is
achieved using the low level commands directly.

Trigger Count

To get the fastest measurement speed the a TRIG:COUNT must be set to
return multiple measurements for each FETCh command. For average only
measurements a count of 4 is required, however, 10 is recommended. In
normal mode (peak measurements) a count of 50 is required to attain
1000 readings per second.

N1913/1914A EPM Series Power Meters Programming Guide 47

1 Power Meter Remote Operation

Fast Mode

In the highest speed setting, the limiting factor tends to be the speed of
the controller being used to retrieve results from the power meter, and to
a certain extent, the volume of remote traffic. The latter can be reduced
using the FORMat REAL command to return results in binary format. The
former is a combination of two factors:

• the hardware platform being used

• the programming environment being used

48 N1913/1914A EPM Series Power Meters Programming Guide

How Measurements are Calculated

TRIGger

DISPlay

WINDow2

:FORMat
:METer
: SELect [1]|2

: NUMeric[1 ]:RESolu tion

:NUMeric2:RESolution

Upper Meas

Lowe r Me a s

UNIT4

Conversion

:P OW

CAL C ul ate2

Maths O ffset Relat ive

Limits

:MA TH : GA IN :REL

:LIM

Swit ch
Swit ch

:FEED

UNIT2

Conversion

:P OW

UNIT 3

Conv er sion

:POW

UNIT 1

Conv er sion

:POW

CAL C ul ate4

Maths O ffset Relat ive

Limits

:MA TH : GA IN :REL

:LIM

Swit ch
Swit ch

:FEED

CAL C ul ate1

Maths O ffset Relat ive

Limits

:MA TH : GA IN :REL

:LIM

Swit ch
Swit ch

:FEED

CAL C ul ate3

Maths O ffset Relat ive

Limits

:MA TH : GA IN :REL

:LIM

Swit ch
Swit ch

:FEED

[WINDo w[ 1]]

:FORMat
:METer
: SELect [1]|2

: NUMeric[1 ]:RESolu tion

:NUMeric2:RESolution

Upper Meas

Lowe r Me a s

SENSe1

Sensor Filter

Freq.

Corr.

Offset

Duty

Cycle

:SPEe d

:POW:A C:RANG

:POW:AC:RANG:AUTO:DIR

:DET :FUNC

:AVER[1]

:FREQ
:CORR:CFAC
: CORR:CSET

:CORR:GAIN2

:CORR:LOSS2

:CORR:DCYC

SENSe2

Sensor Filter

Freq.

Corr .

Offset

Duty

Cycle

:SPEed

:PO W: AC:RANG

:POW:AC:RANG:AUTO:DIR

:DET:FU NC

:AVER[1]

:FR EQ
:CORR:CFAC
:CORR:CSET

:CORR:GAIN2

:CO RR:LOSS2

: CORR:DCYC

:CO NTrast
:ENA Ble
:FOR Mat

FO R M at

Swi tc h
Swi tc h
Swi tc h
Swi tc h

MEAS?
READ?
FETC?

CONF

NOTE

Figure 1- 6 details how measurements are calculated. It shows the order in

which the various power meter functions are implemented in the
measurement calculation.

Power Meter Remote Operation 1

N1913/1914A EPM Series Power Meters Programming Guide 49

Figure 1-6 How Measurement are Calculated

The MEASure commands in this figure can be replaced with the FETCh?
and READ? commands.

All references to Channel B in the above diagram refer to the N1914A only.

1 Power Meter Remote Operation

Status Reporting

Status reporting is used to monitor the power meter to determine when
events have occurred. Status reporting is accomplished by configuring and
reading status registers.

The power meter has the following main registers:

•Status Register

•Standard Event Register

•Operation Status Register

• Questionable Status Register

• Device Status Register

There are other registers that exist “behind” the main registers, and are
described later in this chapter.

Status and Standard Event registers are read using the IEEE- 488.2
common commands.

Operation and Questionable Status registers are read using the SCPI
STATus command subsystem.

The General Status Register Model

The generalized status register model shown in Figure 1-7 is the building
block of the SCPI status system. This model consists of a condition
register, a transition filter, an event register and an enable register. A set
of these registers is called a status group.

50 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

0
1

2

Bit 0

Bit 1

Bit 2

Bit 3

Cond ition

Register

Tra n si t io n

Filter

Event

Register

Enable

Register

Logical OR

Summary

Bit

Figure 1-7 Generalized Status Register Model

When a status group is implemented in an instrument, it always contains
all of the component registers. However, there is not always a
corresponding command to read or write to ever y register.

Condition Register

The condition register continuously monitors the hardware and firmware
status of the power meter. There is no latching or buffering for this
register, it is updated in real time. Condition registers are read- only.

Transition Filter

The transition filter specifies which types of bit state changes in the
condition registers and set corresponding bits in the event register.
Transition filter bits may be set for positive transitions (PTR), negative
transitions (NTR), or both. Transition filters are read-write. They are
unaffected by *CLS or queries. After STATus:PRESet the NTR register is
set to 0 and all bits of the PTR are set to 1.

Event Register

The event register latches transition events from the condition register as
specified by the transition filter. Bits in the event register are latched and
on setting they remain set until cleared by a query or a *CLS. Also on
setting, an event bit is no longer affected by condition changes. It remains
set until the event register is cleared; either when you read the register or
when you send the *CLS (clear status) command. Event registers are
read- only.

N1913/1914A EPM Series Power Meters Programming Guide 51

1 Power Meter Remote Operation

00
01

110

011

0
1

00
0

0

000

1

11

011

0

1

000

1

10

0

1

0

1

00
01

0

01

0
1

00

0

0

0

0

00
000
000

1

0

0

0

0

0

Condition

PTR

NTR

Enable

Condition

Event

Summary Bit

Condition

Event

Summary Bit

Condition

Event

Summary Bit

Condition

Event

Summary Bit

Condition

Event

Summary Bit

1

0

T1 T2 T3

T4

T5

00

0

0

00

***

*

marks when event register is read

Enable Register

The enable register specifies the bits in the event register that can
generate a summary bit. The instrument logically ANDs corresponding bits
in the event and enable registers and ORs all the resulting bits to obtain a
summary bit. Enable registers are read- write. Querying an enable register
does not affect it.

An Example Sequence

Figure 1- 8 illustrates the response of a single bit position in a typical

status group for various settings. The changing state of the condition in
question is shown at the bottom of the figure. A small binary table shows
the state of the chosen bit in each status register at the selected times T1
to T5.

Figure 1-8 Typical Status Register Bit Changes

52 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

How to Use Register

There are two methods to access the information in status groups:

• the polling method, or

• the service request (SRQ) method. (GPIB mode only)

Use the polling method when:

• your language/development environment does not support SRQ
interrupts.

• you want to write a simple, single purpose program and do not want
to add the complexity of setting an SRQ handler.

Use the SRQ method when you:

• need time critical notification of changes.

• are monitoring more than one device which supports SRQ interrupts.

• need to have the controller do something else while it is waiting.

• cannot afford the performance penalty inherent to polling.

The Condition Polling Method

In this polling method, the power meter has a passive role. It only informs
the controller that conditions have changed when the controller asks.
When you monitor a condition with the polling method, you must:

1 Determine which register contains the bit that monitors the

condition.

2 Send the unique query that reads that register.

3 Examine the bit to see if the condition has changed.

The polling method works well if you do not need to know about the
changes the moment they occur. The SRQ method is more effective if you
must know immediately when a condition changes. Detecting an immediate
change in a condition using the polling method requires your program to
continuously read the registers at very short intervals. This is not
particularly efficient and there is a possibility that an event may be
missed.

N1913/1914A EPM Series Power Meters Programming Guide 53

1 Power Meter Remote Operation

NOTE

For example on measurement polling, refer to Figure B- 1 on page B-2.

The SRQ Method

When a bit of the Status Register is set and has been enabled to assert
SRQ (*SRE command), the power meter sets the GPIB SRQ line true. This
interrupt can be used to interrupt your program, suspending its current
operation, and find out what service the power meter requires. Refer to
your computer and language manuals for information on how to program
the computer to respond to the interrupt.

To allow any of the Status Register bits to set the SRQ line true, you must
enable the appropriate bit(s) with the *SRE command. For example, if
your application requires an interrupt whenever a message is available in
the output queue (Status Register bit 4, decimal weight 16). To enable bit
4 to assert SRQ, use the command *SRE 16.

You can determine which bits are enabled in the Status Register using *SRE?. This
command returns the decimal weighted sum of all the bits.

Procedure

• Send a bus device clear message

• Clear the event registers with the *CLS (clear status) command

• Set the *ESE (standard event register) and *SRE (status byte register)
enable masks

• Enable your bus controller’s IEEE-488 SRQ interrupt

Examples

The following two examples are written in HP BASIC and illustrate
possible uses for SRQ. In both cases, it is assumed that the power meter
has been zeroed and calibrated.

54 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Example 1:

10 ! Program to generate an SRQ when a channel A sensor
20 ! connect or disconnect occurs
30 !
40 ASSIGN @Pm TO 713 ! Power meter GPIB address
50 ON ON INTR 7 GOTO Srq_i! Define service request handler
60 CLEAR @Pm ! Selective device clear
70 OUTPUT @Pm;”*CLS;*RST” ! Clear registers and resetmeter
80 !
90 ! Configure the device status register so that a sensor
100 ! connect or disconnect on channel A will cause an SRQ.
110 !
120 OUTPUT @Pm;”STAT:DEV:ENAB 2”
130 OUTPUT @Pm;”STAT:DEV:NTR 2”
140 OUTPUT @Pm;”STAT:DEV:PTR 2”
150 OUTPUT @Pm;”*SRE 2”
160 !
170 ENABLE INTR 7;2 ! Enable an SRQ to cause an interrupt
180 LOOP ! Idle loop
190 ! Forever
200 END LOOP
210 !
220 ! When a SRQ is detected, the following routine will
service it.
230 !
240 Srq_i: !
250 St=SPOLL(@Pm) ! Serial Poll (reads status byte)

260 IF BIT(St,1)=1 THEN ! Device status reg bit set ?
270 OUTPUT @Pm;”STAT:DEV:EVEN?” ! Yes , read register

280 ENTER @Pm;Event ! (this also clears it)

290 OUTPUT @Pm;”STAT:DEV:COND?”
300 ENTER @Pm;Cond
310 IF Cond=0 THEN
320 PRINT “Sensor disconnected”
330 ELSE
340 PRINT “Sensor connected”
350 END IF
360 END IF
370 GOTO 170 ! Return to idle loop

N1913/1914A EPM Series Power Meters Programming Guide 55

1 Power Meter Remote Operation

380 END

Example 2:

10 ! Program to generate an SRQ when an over limit
20 ! condition occurs.
30 !
40 ASSIGN @Pm TO 713 ! Power meter GPIB address
50 ON INTR 7 GOTO Srq_i ! Define service request handler
60 CLEAR @Pm ! Selective device clear
70 OUTPUT @Pm;”*CLS” ! Clear registers
80 OUTPUT @Pm;”SYST:PRES” ! Preset meter
90 !
100 ! Set upper limit to 2dBm and configure the operation
status
110 ! so that an over limit condition will cause an SRQ.
120 !
130 OUTPUT @Pm;”CALC:LIM:UPP 2DBM”
140 OUTPUT @Pm;”CALC:LIM:STAT ON”
150 OUTPUT @Pm;”STAT:OPER:PTR 4096”
160 OUTPUT @Pm;”STAT:OPER:ENAB 4096”
170 OUTPUT @Pm;”*SRE 128”
180 !
190 ENABLE INTR 7;2 ! Enable an SRQ to cause an interrupt
200 LOOP ! Idle loop
210 ! Forever
220 END LOOP
230 !
240 ! When a SRQ is detected, the following routine will
service it.
250 !

260 Srq_i: !
270 St=SPOLL(@Pm) ! Serial Poll (reads status byte)
280 IF BIT(St,7)=1 THEN ! Operation status bit set?
290 OUTPUT @Pm;”STAT:OPER?”! Yes , read register
300 ENTER @Pm;Oper ! (this also clears it)
310 OUTPUT @Pm;”STAT:OPER:ULF?”
320 ENTER @Pm;Ulf
330 IF Ulf=2 THEN PRINT “Over limit detected”
340 END IF
350 GOTO 190 ! Return to idle loop

56 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

360 END

Status Registers

The Status System in the power meter is shown in Figure 1-9. The
Operation Status and Questionable Status groups are 16 bits wide, while
the Status Byte and Standard Event groups are 8 bits wide. In all 16- bit
groups, the most significant bit (bit 15) is not used and is always set to 0.

N1913/1914A EPM Series Power Meters Programming Guide 57

1 Power Meter Remote Operation

Questionable Status

Logical OR

Condit ion E vent Enable

Operation Sta tus

Logical OR

Condition Event Enable

Standard Event

Logical OR

Event

Enable

*ESR

*ESE

Status Byte

Logical OR

*STB?

*SRE

MAV

0
1
2

QUE

ESB

RQS/MSS

OPR

MAV

0
1
2

QUE

ESB

X

OPR

Output Q ueue

Device Status

Logical OR

Condition Event Enable

Error/Event Queue

Figure 1-9 Status System

58 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

The Status Byte Summary Register

The status byte summary register reports conditions from other status
registers. Query data waiting in the power meter’s output buffer is
immediately reported through the “message available” bit (bit 4). Clearing
an event register clears the corresponding bits in the status byte summary
register. Reading all messages in the output buffer, including any pending
queries, clears the message available bit.

Ta b le 1 -5 Bit Definitions - Status Byte Register

Bit Number Decimal

Definition

Weight

0 1 Not Used (Always set to 0)

1 2 Device Status Register summary bit.

One or more bits are set in the Device Status Register (bits
must be “enabled” in enable register)

2 4 Error/Event Queue

3 8 Questionable Status Register summary bit.

One or more bits are set in the Questionable Status Register
(bits must be “enabled” in enable register).

4 16 Data Available

Data is available in the power meter’s output buffer.

532Standard Event

One or more bits are set in the Standard Event register (bits
must be “enabled” in enable register).

664Request Service

The power meter is requesting service (serial poll).

7 128 Operation Status Register summary bit.

One or more bits are set in the Operation Status Register (bits
must be “enabled” in enable register).

Particular bits in the status byte register are cleared when:

• The standard event, Questionable status, operation status and device
status are queried.

• The error/event queue becomes empty.

• The output queue becomes empty.

N1913/1914A EPM Series Power Meters Programming Guide 59

1 Power Meter Remote Operation

The status byte enable register (SRE, service request enable) is cleared
when you:

•cycle the instrument power.

•execute a *SRE 0 command.

Using *STB? to Read the Status Byte

The *STB? (status byte query) command is similar to a serial poll except
it is processed like any other power meter command. The *STB? command
returns the same result as an IEEE- 488 serial poll except that the request
service bit (bit 6) is not cleared if a serial poll has occurred. The *STB?
command is not handled automatically by the IEEE-488 bus interface
hardware and the command is executed only after previous commands
have completed. Using the *STB? command does not clear the status byte
summary register.

The Standard Event Register

The standard event register reports the following types of instrument
events: power- on detected, command and syntax errors, command
execution errors, self- test or calibration errors, query errors, or when an
overlapped command completes following a *OPC command. Any or all of
these conditions can be reported in the standard event summary bit
through the enable register. You must write a decimal value using the
*ESE (event status enable) command to set the enable register mask.

Ta b le 1 -6 Bit Definitions - Standard Event Register

Bit
Number

0 1 Operation Complete

1 2 Not Used. (Always set to 0.)

2 4 Query Error

Decimal
Value

Definition

All overlapped commands following an *OPC command have
been completed.

A query error occurred, refer to error numbers 410 to 440 in the
user’s guide.

60 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Bit
Number

3 8 Device Error

4 16 Execution Error

5 32 Command Error

6 64 User request.

7128Power On

Decimal
Value

Definition

A device error occurred, refer to error numbers 310 to 350 in the
user’s guide.

An execution error occurred, refer to error numbers 211 to 241
in the user’s guide.

A command syntax error occurred, refer to error numbers 101 to
161 in the user’s guide.

Power has been turned off and on since the last time the event
register was read or cleared.

The standard event register is cleared when you:

•send a *CLS (clear status) command.

• query the event register using the *ESR? (event status register)
command.

The standard event enable register is cleared when you:

•cycle the instrument power.

•execute a *ESE 0 command.

Questionable Status Register

The questionable status register provides information about the quality of
the power meter’s measurement results. Any or all of these conditions can
be reported in the questionable data summary bit through the enable
register. You must write a value using the STATus:QUEStionable:ENABle
command to set the enable register mask.

The questionable status model is shown in the pullout at the end of this
chapter.

The following bits in these registers are used by the power meter.

N1913/1914A EPM Series Power Meters Programming Guide 61

1 Power Meter Remote Operation

Ta b le 1 -7 Bit Definitions - Questionable Status Registers

Bit
Number

0 to 2 - Not used

38 POWer Summary

4 to 7 - Not used

8 256 CALibration Summary

9 512 Power On Self Test

10 to 14 - Not Used

15 - Not used (always 0)

Decimal
Weight

Definition

The condition bits are set and cleared under the following conditions:

Ta b le 1 -8 Bit change conditions for Questionable Status Register

Bit

Meaning EVENts Causing Bit Changes

Number

3POWer

Summary

This is a summary bit for the Questionable POWer Register.

• SET:
Error –230, “Data corrupt or stale”
Error –231, “Data questionable;Input Overload”

Error –231, “Data questionable;Input Overload ChA”

Error –231, “Data questionable;Input Overload ChB”
Error –231, “Data questionable;PLEASE ZERO”

Error –231, “Data questionable;PLEASE ZERO ChA”

Error –231, “Data questionable;PLEASE ZERO ChB”

Error –231, ”Data questionable;Lower window log error”

Error –231, ”Data questionable;Upper window log error”

• CLEARED: When no errors are detected by the power
meter during a measurement covering the causes given
for it to set.

*

*

*

*

*

*

62 N1913/1914A EPM Series Power Meters Programming Guide

Power Meter Remote Operation 1

Bit

Meaning EVENts Causing Bit Changes

Number

8CALibration

Summary

9Power On Self

Te st

* N1914A only

This is a summary bit for the Questionable CALibration
Register.

• SET:

• CLEARED: When any of the commands listed above

• SET: This bit is set when the power on self test fails.

• CLEARED: When the power on self test passes.

These may be caused by

CALibration[1|2]:ZERO:AUTO ONCE or
CALibration[1|2]:AUTO ONCE or
CALibration[1|2][:ALL] or
CALibration[1|2][:ALL]?.

Error –231, “Data questionable; ZERO ERROR”
Error –231, “Data questionable; ZERO ERROR ChA”

Error –231, “Data questionable; ZERO ERROR ChB”
Error –231, “Data questionable; CAL ERROR”

Error –231, “Data questionable; CAL ERROR ChA”

Error –231, “Data questionable; CAL ERROR ChB”

succeed and no errors are placed on the error queue.

*

*

*

*

Operation Status

The Operation Status group monitors conditions in the power meter’s
measurement process.

The Operation status model is shown in the pullout at the end of this
chapter.

The following bits in these registers are used by the power meter:

Ta b le 1 -9 Bit Definitions - Operation Status

Bit Number Decimal

Weight

0 1 CALibrating Summary

1 - 3 - Not used

N1913/1914A EPM Series Power Meters Programming Guide 63

Definition

1 Power Meter Remote Operation

Bit Number Decimal

Definition

Weight

416MEASuring Summary

5 32 Waiting for TRIGger Summary

6 - 9 - Not used

10 1024 SENSe Summary

11 2048 Lower Limit Fail Summary

12 4096 Upper Limit Fail Summary

13 to 14 - Not used

15 - Not used (always 0)

The condition bits are set and cleared under the following conditions:

Table 1-10 Bit change conditions for Operation Status

Bit

Meaning EVENts Causing Bit Changes

Number

0 CALibrating This is a summary bit for the Operation CALibrating Register.

• SET: At beginning of zeroing (CALibration:ZERO:AUTO ONCE) and at the
beginning of calibration (CALibration:AUTO ONCE). Also for the compound
command/query CALibration[:ALL]?, this bit is set when sensor zeroing
begins.

• CLEARED: At the end of zeroing or calibration.

4 MEASuring This is a summary bit for the Operation MEASuring Register.

• SET: When the power meter is taking a measurement.

• CLEARED: When the measurement is finished.

5Waiting for

TRIGger

10 SENSe This is a summary bit for the Operation SENSe Register.

This is a summary bit for the Operation TRIGger Register.

• SET: When the power meter enters the “wait for trigger” state.

• CLEARED: When the power meter enters the “idle” state.

• SET: When the power meter is reading data from the power sensor’s EEPROM.

• CLEARED: When the power meter is not reading data from the power sensor’s
EEPROM.

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Bit

Meaning EVENts Causing Bit Changes

Number

11 Lower Limit

Fail

12 Upper Limit

Fail

Device Status Register

The device status register set contains bits which give device dependent
information.

The following bits in these registers are used by the power meter:

Table 1-11 Bit Definitions - Device Status Register

This is a summary bit for the Lower Limit Fail Register.

• SET: If a measurement is made and either a channel or window lower limit test
fails.

• CLEARED: If a measurement is made and the lower limit test is not enabled or
the test is enabled and passes.

This is a summary bit for the Upper Limit Fail Register.

• SET: If a measurement is made and either a channel or window upper limit test
fails.

• CLEARED: If a measurement is made and the upper limit test is not enabled or
the test is enabled and passes.

Bit
Number

0- Not used

1 2 Channel A sensor connected

2 4 Channel B sensor connected (N1914A only)

38Channel A sensor error

4 16 Channel B sensor error (N1914A only)

5 32 Channel A sensor Front/Rear

6 64 Channel B sensor Front/Rear (N1914A only)

7 128 Channel C sensor connected

8 256 Channel D sensor connected

9512Not used

Decimal
Weight

Definition

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Bit
Number

10 1024 Not used

11 2048 Battery critical

12 4096 Over temperature

13 8192 Fan failed

14 16384 Front panel key press

15 - Bit 15 always 0

Decimal
Weight

Definition

The condition bits are set and cleared under the following conditions:

Table 1-12 Bit change conditions for Device Status Register

Bit

Meaning EVENts Causing Bit Changes

Number

1 Channel A

sensor
connected

2 Channel B

sensor
connected

3 Channel A

error

4 Channel B

error

5 Channel A

Front/Rear

• SET: When a power sensor is connected to the Channel A
input.

• CLEARED: When no power sensor is connected to the
Channel A input.

• SET: When a power sensor is connected to the Channel B
input.

• CLEARED: When no power sensor is connected to the
Channel B input.

• SET: If the power sensor EEPROM on Channel A has failed
or if there are power sensors connected to both the rear
and front panel Channel A connectors.

• CLEARED: In every other condition.

• SET: If the power sensor EEPROM on Channel B has failed
or if there are power sensors connected to both the rear
and front panel Channel B connectors.

• CLEARED: In every other condition.

• SET: If a power sensor is connected to the Channel A rear
panel.

• CLEARED: If a power sensor is connected to the Channel A
front panel.

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Bit

Meaning EVENts Causing Bit Changes

Number

6 Channel B

Front/Rear

7 Channel C

sensor
connected

8 Channel D

sensor
connected

11 Battery critical This is an event, and DOES NOT set the condition register. The

12 Over

temperature

13 Fan failed This is an event, and DOES NOT set the condition register. The

14 Front Panel

Key Press

• SET: If a power sensor is connected to the Channel B rear
panel.

• CLEARED: If a power sensor is connected to the Channel B
front panel.

• SET: When a power sensor is connected to the Channel C
input.

• CLEARED: When no power sensor is connected to the
Channel C input.

• SET: When a power sensor is connected to the Channel D
input.

• CLEARED: When no power sensor is connected to the
Channel D input.

bit is set in the event register which is cleared when read. Note
that the transition registers are of no use for this bit.

This is an event, and DOES NOT set the condition register. The
bit is set in the event register which is cleared when read. Note
that the transition registers are of no use for this bit.

bit is set in the event register which is cleared when read. Note
that the transition registers are of no use for this bit.

This is an event, and DOES NOT set the condition register. The
bit is set in the event register which is cleared when read. Note
that the transition registers are of no use for this bit.

Using the Operation Complete Commands

The *OPC? and *OPC commands allow you to maintain synchronization
between the computer and the power meter. The *OPC? query command
places an ASCII character 1 into the power meter’s output queue when all
pending power meter commands are complete. If your program reads this
response before continuing program execution, you can ensure
synchronization between one or more instruments and the computer.

The *OPC command sets bit 0 (Operation Complete) in the Standard Event

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1 Power Meter Remote Operation

NOTE

Status Register when all pending power meter operations are complete. By
enabling this bit to be reflected in the Status Register, you can ensure
synchronization using the GPIB serial poll.

For LAN and USB use the *STB? command. See “Using *STB? to Read the Status

Byte” on page 60.

Procedure

• Send a device clear message to clear the power meter’s output buffer.

• Clear the event registers with the *CLS (clear status) command.

• Enable operation complete using the *ESE 1 command (standard event

register).

• Send the *OPC? (operation complete query) command and enter the

result to assure synchronization.

• Send your programming command string, and place the *OPC

(operation complete) command as the last command.

• Send the *STB? (status byte query) command to poll the register. This

command does not clear the status byte summary register.

In GPIB mode only you can use a serial poll to check to see when bit
5 (standard event) is set in the status byte summary register. You could
also configure the power meter for an SRQ interrupt by sending *SRE
32 (status byte enable register, bit 5).

Examples

This example program uses the *OPC? command to determine when the
power meter has finished calibrating.

CAL:AUTO ONCE
*OPC?
MEAS:POW:AC?

This example GPIB program, in HP Basic, uses the *OPC command and
serial poll to determine when the power meter has finished calibrating.
The advantage to using this method over the *OPC? command is that the
computer can perform other operations while it is waiting for the power
meter to finish calibrating.

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10 ASSIGN @Power TO 713
20 OUTPUT @Power;“*CLS”
30 OUTPUT @Power;“*ESE 1”
40 OUTPUT @Power;“CAL:AUTO ONCE;*OPC”
50 WHILE NOT BIT(SPOLL(@Power),5)
60 !(Computer carries out other operations here)
70 END WHILE
80 OUTPUT @Power;“MEAS:POW:AC?”
90 ENTER @Power;Result
100 PRINT Result
110 END

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Saving and Recalling Power Meter Configurations

To reduce repeated programming, up to ten power meter configurations
can be stored in the power meter’s non- volatile memory. The error list,
remote addresses, sensor calibration table data, zeroing and calibration
information are not stored.

How to Save and Recall a Configuration

Power meter configurations are saved and recalled with the following
commands:

*SAV <NRf>
*RCL <NRf>

The range of values for <NRf> in the above commands is 1 to 10.

Example Program

10 ASSIGN @POWER TO 713
20 !Configure the power meter
30 OUTPUT @POWER;“UNIT:POW W”
40 OUTPUT @POWER;“SENS:CORR:LOSS2 -10”
50 OUTPUT @POWER;“SENS:CORR:LOSS2:STAT ON”
60 !Save the configuration
70 OUTPUT @POWER;“*SAV 5”
80 PRINT “Configuration Saved”
90 !Now reset the power meter
100 OUTPUT @POWER;“*RST”
110 ! Recall the configuration
120 OUTPUT @POWER;”*RCL 5”
130 PRINT “Configuration Recalled”
140 PRINT “Save and Recall complete”
150 END

70 N1913/1914A EPM Series Power Meters Programming Guide

Using Device Clear to Halt Measurements

NOTE

Device clear is an IEEE- 488 low- level bus message which can be used to
halt measurements in progress. Different programming languages and
IEEE- 488 interface cards provide access to this capability through their
own unique commands. The status registers, the error queue, and all
configuration states are left unchanged when a device clear message is
received. Device clear performs the following actions.

• All measurements in progress are aborted.

• The power meter returns to the trigger “idle state”.

• The power meter’s input and output buffers are cleared.

• The power meter is prepared to accept a new command string.

For interfaces the that do not support a low-level device clear, use the ABORt command.

Power Meter Remote Operation 1

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1 Power Meter Remote Operation

“B” Subsystem

:G :I:H

:M

:N=:B:H:N

“A” S u bs ys tem

:D:F:E

“C” Subsystem

:J :L=:C:L:K

An Introduction to the SCPI Language

Standard Commands for Programmable Instruments (SCPI) defines how
you communicate with an instrument from a bus controller. The SCPI
language uses a hierarchical structure similar to the file systems used by
many bus controllers. The command tree is organized with root- level
commands (also called subsystems) positioned at the top, with multiple
levels below each root- level command. You must specify the complete path
to execute the individual lower- level commands.

Figure 1-10 Hierarchical structure of SCPI

Mnemonic Forms

Each keyword has both a long and a short form. A standard notation is
used to differentiate the short form keyword from the long form keyword.
The long form of the keyword is shown, with the short form portion
shown in uppercase characters, and the rest of the keyword shown in
lowercase characters. For example, the short form of TRIGger is TRIG.

Using a Colon (:)

When a colon is the first character of a command keyword, it indicates
that the next command mnemonic is a root- level command. When a colon
is inserted between two command mnemonics, the colon moves the path

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Power Meter Remote Operation 1

down one level in the present path (for the specified root-level command)
of the command tree. You must separate command mnemonics from each
other using a colon. You can omit the leading colon if the command is the

first of a new program line.

Using a Semicolon (;)

Use a semicolon to separate two commands within the same command
string. The semicolon does not change the present path specified. For
example, the following two statements are equivalent. Note that in the first
statement the first colon is optional but the third is compulsory.

:DISP:FORM DIG;:DISP:RES 2
:DISP:FORM DIG;RES 2

Using a Comma (,)

If a command requires more than one parameter, you must separate
adjacent parameters using a comma.

Using Whitespace

You must use whitespace characters, [tab], or [space] to separate a
parameter from a command keyword. Whitespace characters are generally
ignored only in parameter lists.

Using “?” Commands

The bus controller may send commands at any time, but a SCPI
instrument may only send responses when specifically instructed to do so.
Only query commands (commands that end with a “?”) instruct the
instrument to send a response message. Queries return either measured
values or internal instrument settings.

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1 Power Meter Remote Operation

NOTE

If you send two query commands without reading the response from the first, then attempt
to read the second response, you may receive some data from the first response followed
by the complete second response. To avoid this, do not send a query command without
reading the response. When you cannot avoid this situation, send a device clear before
sending the second query command.

Using “*” Commands

Commands starting with a “*” are called common commands. They are
required to perform the identical function for all instruments that are
compliant with the IEEE- 488.2 interface standard. The “*” commands are
used to control reset, self-test, and status operations in the power meter.

Syntax Conventions

Throughout this guide, the following conventions are used for SCPI
command syntax.

• Square brackets ([]) indicate optional keywords or parameters.

• Braces ({}) enclose one or more parameters that may be included zero
or more times.

• Triangle brackets (<>) indicate that you must substitute a value for the
enclosed parameter.

• Bars (|) can be read as “or” and are used to separate alternative
parameter options.

Syntax Diagram Conventions

• Solid lines represent the recommended path.

• Ovals enclose command mnemonics. The command mnemonic must be
entered exactly as shown.

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Power Meter Remote Operation 1

<digit>

<upper-case

alpha>

<upper-case

alpha>

• Dotted lines indicate an optional path for by passing secondary
keywords.

• Arrows and curved intersections indicate command path direction.

SCPI Data Types

The SCPI language defines different data formats for use in program
messages and response messages. Instruments are flexible listeners and
can accept commands and parameters in various formats. However, SCPI
instruments are precise talkers. This means that SCPI instruments always
respond to a particular query in a predefined, rigid format.

<boolean> Definition

Throughout this document <boolean> is used to represent ON|OFF|<NRf>.
boolean parameters have a value of 0 or 1 and are unitless. ON
corresponds to 1 and OFF corresponds to 0.

On input, an <NRf> is rounded to an integer. A nonzero result is
interpreted as 1.

Queries always return a 1 or 0, never ON or OFF.

<character_data> Definition

Throughout this document <character_data> is used to represent
character data, that is, A - Z, a - z, 0 -9 and _ (underscore). For example:
START and R6_5F. The format is defined as:

Figure 1-11 Format of <character_data>

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1 Power Meter Remote Operation

<NAN> Definition

Not a number (NAN) is represented as 9.91 E37. Not a number is defined

in IEEE 754.

<non-decimal numeric> Definition

Throughout this document <non-decimal numeric> is used to represent
numeric information in bases other than ten (that is, hexadecimal, octal
and
binary). The following syntax diagram shows the standard for these three
data structures. For examples, #HA2F, #ha4e, #Q62, #q15, #B01011.

76 N1913/1914A EPM Series Power Meters Programming Guide

A/a

B/b
C/c
D/d

E/e

F/f

<digit>

H/h

1

2
3
4
5
6

0

7

Q/q

0

1

#

B/b

Power Meter Remote Operation 1

Figure 1-12 Format of <non-decimal numeric>

Refer to section 7.7.4.1 of IEEE 488.2 for further details.

<NRf> Definition

Throughout this document <NRf> is used to denote a flexible numeric
representation. For example: +200; –56; +9.9E36. Refer to section 7.7.2.1 of

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1 Power Meter Remote Operation

digit

+

digit

+

digit

IEEE 488.2 for further details.

<NR1> Definition

Throughout this document <NR1> numeric response data is defined as:

Figure 1-13 Format of <NR1>

For example:

•146

•+146

• –12345

Refer to section 8.7.2 of IEEE 488.2 for further details.

<NR2> Definition

Throughout this document <NR2> numeric response data is defined as:

Figure 1-14 Format of <NR2>

For example:

•12.3

• +1.2345

• –0.123

Refer to section 8.7.3 of IEEE 488.2 for further details.

78 N1913/1914A EPM Series Power Meters Programming Guide