Agilent 8920B Programming Manual

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Agilent Technologies 8920B

RF Communications Test Set

GPIB Programmer’s Guide

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Firmware Versions: Agilent 8920B B.06.00 and above

Agilent Part Number: 08920-90222

Printed in U. S. A.

April 2000

ENTER

PRESE

GHz

MHz

kHz

Hzms% Ωppm

MEMO

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MAX

Rev. D

Notice

No part of this manual may be re produced in any form or by any means (inc luding electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Tech nologies Inc. as governed by United States and international copy right laws.

The material contained in this document is subject to change without notice. Agilent Technologies makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Agilent Technologies Inc. shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

U.S. Government users will receive no greater than Limited Rights as defined in FAR

52.227-14 (June 1987) or DF AR 252.227-7015 ( b)(2) (November 1995) , as applicable in any technical data.

Agilent Technologies Learning Products Department 24001 E. Mission Liberty Lake, WA 99019-9599 U.S.A.

Trademark Acknowledgments

Microsoft®, Microsoft® Windows, and MS-DOS® are registered trademarks of Microsoft Corporation.

ProComm INC.

Edition/Print Date

All Editions and Updates of this manual and their creation dates are listed below.

is a registered trademark of DATASTORM TECHNOLOGIES,

Rev. A . . . . .October 1996

Rev. B . . . . .December 1998

Rev. C . . . . .October 1999

Rev. D . . . . .April 2000

Safety Summary

The following general safety precautions must be observed during all phases of operation of this instrument. Failure to comply with these precautions or with specif ic 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.

GENERAL

This product is a Safety Class 1 instrument (provided with a protective earth terminal). The prot ective f eatures of thi s product may be impaire d if it is used in a manner not specified in the operation instructions.

All Light Emitting Diodes (LEDs) used in this product are Class 1 LEDs as per IEC 60825-1.

This product has be en designed and tested in acc ordance with IEC Publication 1010, "Safety Requirements for Electronic Measuring Apparatus," and has been supplied in a safe condition. This instruction documentation contains information and warnings which must be followed by the user to ensure safe operation and to maintain the product in a safe condition.

ENVIRONMENTAL CONDITIONS

This instrument is intended for indoor use in an installation category II, pollution degree 2 environment. It is designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range.

Ventilation Requirements: When installing the product in a cabinet, the convection into and out of the product must not be restricted. The ambient temperature (outside the cabinet) must be less than the maximum operating

temperature of the product by 4° C for every 100 watts dissipated in the cabinet. If the total power dissipated in the cabinet is greater than 800 watts, then forced convection must be used.

BEFORE APPLYING POWER

Verify that the product is set to match the available line voltage, the correct fuse is installed, and all safety precau tions are taken. Note the instrument's external markings described under Safety Symbols.

GROUND THE INSTRUMENT

To minimize shock hazard, the instrument chassis and cover must be connected to an electrical protective earth ground. The instrument must be connected to the ac power mains through a grounded power cable, with the ground wire firmly connected to an electrical ground (safety ground) at the power outlet. Any interruption of the protective (grounding) conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury.

FUSES

Only fuses with the required rated cur rent, voltage, and specified ty pe (normal blow, time delay, etc.) should be used. Do not use repaired fuses or shortcircuited fuse holders. To do so could cause a shock or fire hazard.

DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE

Do not operate the instrument in the presence of flammable gases or fumes.

DO NOT REMOVE THE INSTRUMENT COVER

Operating personnel must not remove instrument covers. Component replacement and inter nal adj ustments mus t be made o nly by quali fied s ervic e personnel.

Instruments that appea r damaged or defective shou ld be made inoperativ e and secured against unintended operation until they can be repaired by qualified service personnel.

WARNING: The WARNING sign denotes a hazard. It calls attention to a procedure, practice, or

the like, which, if not correctly performed or adhered to, could result in personal injury. Do not proceed beyond a WARNING sign until the in dicated conditions are fully understood and met.The CAUTION sign denotes a hazard. It calls attention to an operating procedure, or the like, which, if not correctly performed or adhered to, could result in damage to or destruction of part or all of the product. Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met.

Product Markings

Safety Symbols

Caution, refer to accompanying documents

Warning, risk of electric shock

Earth (ground) terminal

Alternating current

Frame or chassis terminal

Standby (supply). Units with this symbol are not completely disconnected from ac mains when this swi tch is off.

T o completely disconnect the unit from ac mains, either disconnect the power cor d, or have a qualified electrician install an external switch.

CE - the CE mark is a regist ered trademark of the Euro pean Community . A CE mark accompanied by a year indicated the year the design was proven.

CERTIFICATION

CSA - the CSA mark is a registered trademark of the Canadian Standards Association.

Agilent Technologies certifies that this product met its published specifications at t he ti me of shi pment from the factory. Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology, to the extent allowed

by the Institute’s calibration facility, and to the calibration facilities of other International Standards Organization members

Agilent Technologies Warranty Statement for Commercial Products Agilent Technologies 8920B RF Communications Test Set

Duration of Warranty: 1 year

1 Agilent Technologies warrants Agilent Technologies hardware, accessories and

supplies against defects in materials and workmanship for the period specified above. If Agilent Technologies receives notice of such defects during the warr anty period, Agilent Technologies will, at its option, either repair or replace products which prove to be defective. Replacement p roducts may be either new or like-new.

2 Agilent Technologies warrants that Agilent Technologies software will not fail to

execute its programming instructions, for the period specified above, due to defects in material and workmanship when properly installed and used. If Agilent Technologies receives notice of such defects during the warranty period, Agilent Technologies will replace software media which does not execute its programming instructions due to such defects.

3 Agilent Technologies does not warrant that the operation o f Agilent Technologies

products will be uninterrupted or error free. If Agilent Technologies is unable, within a reasonable time, to repair or replace any product to a condition as warranted, customer will be entitled to a refund of the purchase price upon prompt return of the product.

4 Agilent Technologies products may contain remanufactured parts equivalent to

new in performance or may have been subject to incidental use.

5 The warranty period begins on the date of delivery or on the date of installat ion if

installed by Agilent Technologies. If customer schedules or delays Agilent Technologies install ation more than 3 0 days after deliver y, warranty begins on the 31st day from delivery.

6 Warranty does not apply to defects resulting from (a) improper or inad equate

maintenance or calibrati on, (b) software, interfacing, part s or supplies not supplied by Agilent Technologies, (c) unauthorized modification or misuse, (d) operation outside of the published environmental specifications for the product, or (e) improper site preparation or maintenance.

7 TO THE EXTENT ALLOWED BY LOCAL LAW, THE ABOVE

WARRANTIES ARE EXCLUSIVE AND NO OTHER WARRANTYOR CONDITION, WHETHER WRITTEN OR ORAL IS EXPRESSED OR IMPLIED AND AGILENT TECHNOLOGIES SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTIES OR CONDITIONS OR MERCHANTABILITY, SATISFACTORY QUALITY, AND FITNESS FOR A PARTICULAR PURPOSE.

ASSISTANCE

8 Agilent Technologies will be liable for damage to tangible property per incident

up to the greater of $300,000 or the actual amou nt paid fo r th e pro duct that is the subject of the claim, and for damages for bodily injury or death, to the extent that all such damages are determined by a cou rt of competent jurisdiction to ha ve been directly caused by a defective Agilent Technologies product.

9 TO THE EXTENT ALLOWED BY LOCAL LAW, THE REMEDIES IN THIS

WARRANTY STATEMENT ARE CUSTOMER’S SOLE AND EXCLUSIVE REMEDIES. EXCEPT AS INDICATED ABOVE, IN NO EVENT WILL AGILENT TECHNOLOGIES OR ITS SUPPLIERS BE LIABLE FOR LOSS OF DATA OR FOR DIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL (INCLUDING LOST PROFIT OR DATA), OR OTHER DAMAGE, WHETHER BASED IN CONTRACT, TORT, OR OTHERWISE.

FOR CONSUMER TRANSACTIONS IN AUSTRALIA AND NEW ZEALAND: THE W ARRANTY TERMS CONTAINED IN THIS ST ATEMENT, EXCEPT TO THE EXTENT LAWFULLY PERMITTED, DO NOT EXCLUDE RESTRICT OR MODIFY AND ARE IN ADDITION TO THE MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THIS PRODUCT TO YOU.

Product maintenance agreements and other customer assistance agreements are available for Agilent T echnolo gies products. For any assistance, contact yo ur nearest Agilent Technologies Sales and Service Office.

DECLARATION OF CONFORMITY

according to ISO/IEC Guide 22 and EN 45014

Manufacturer’s Name:

Agilent Technologies

Manufacturer’s Address:

24001 E. Mission Avenue Liberty Lake, Washington 99019-9599 USA

declares that the product

Product Name: Model Number: Product Options:

RF Communications T est Set / Cell Site Test Set A g i l ent Te c h n o l o g i e s 8 9 20A, 8920B , and 8 9 21A This declaration covers all options of the above

product.

conforms to the following Product specifications:

Safety: IEC 1010-1:1990+A1+A2/EN 61010-1:1993

EMC: CISPR 11:1990 / EN 55011:1991 Group 1, Class A

EN 5 008 2-1 : 19 92 IEC 801-2:1991 - 4 kV CD, 8 kV AD IEC 801-3:1984 - 3V/m IEC 801-4:1988 - 0.5 kV Sig. Lines, 1 kV Power Lines

Supplementary Information:

This is a class A product. In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures.

This product herewith complies with the requirements of the Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC and carries the CD-marking accordingly

Spokane, Washington USA November 20, 1998 Vince Roland/Quality Manager

Table 1 Regional Sales Offices

United States of America: Agilent Technologies Test and Measurement Call Center P.O. Box 4026

Englewood, CO 80155-4026

(tel) 1 800 452 4844

Japan:

Agilent Technologies Japan Ltd. Measurement Assist ance Center 9-1 Takakura-Cho, Hachioji-Shi, Tokyo 192-8510, Japan

(tel) (81) 456-56-7832 (fax) (81) 426-56-7840

Asia Pacific:

Agilent Technologies 24/F, Cityplaza One, 111 Kings Road, Taikoo Shing, Hong Kong

Canada: Agilent Technologies Canada Inc. 5150 Spectrum Way Mississauga, Ontario L4W 5G1

(tel) 1 877 894 4414

Latin America:

Agilent Technologies Latin America Region Headquarters 5200 Blue Lagoon Drive, Suite #950 Miami, Florida 33126 U.S. A.

(tel) (305) 267 4245 (fax) (305) 267 4286

Europe: Agilent Technologies European Marketing Organization P.O. Box 999 1180 AZ Amstelveen The Netherlands

(tel) (3120) 547 9999 Australia/New Zealand:

Agilent Technologies Australia Pty Ltd. 347 Burwood Highway Forest Hill, Victoria 3131

Australia (tel) 1 800 629 485 (fax) (61 3) 9272 0749

New Zealand (tel) 0 800 738 378 (fax) (64 4) 802 6881

(tel) (852) 3197 7777 (fax) (852) 2506 9233

Service and Support

Table 2

Any adjustment, maintenance, or re pair of this product must be performe d by qualified personnel. Contact your customer engineer through your local Agilent Technologies Service Center. You can find a list of local service representatives on the Web at:

http://www.agilent-tech.com/services/English/index.html If you do not have access to the Internet , one of these center s can direct you to

your nearest representative:

United States Test and Measurement Call Center (Toll free in US)

Europe

Canada

Japan Measurement Assistance Center

Latin America

Australia/New Zealand

Asia-Pacific

(800) 452-4844

(31 20) 547 9 900

(905) 206-4725

(81) 426 56 7832 |(81) 426 56 7840 (FAX)

(305) 267 4288 (FAX)

1 800 629 485 (Australia) 0800 738 378 (New Zealand)

(852) 2599 7777 (852) 2506 9285 (FAX)

Manufacturer’s Declaration

Herstellerbescheinigung

This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 January 1991.

This product has a sound pressure emission (at the operator position) < 70 dB(A).

• Sound Pressure Lp < 70 dB(A).

• At Operator Position.

• Normal Operation.

• According to ISO 7779:1988/EN 27779:1991 (Type Test).

Diese Information steht im Zusammenhang mit den Anforderungen der

Maschinenlärminformationsverordnung vom 18 Januar 1991.

• Schalldruckpegel Lp < 70 dB(A).

• Am Arbeitsplatz.

• Normaler Betrieb.

• Nach ISO 7779:1988/EN 27779:1991 (Typprüfung).

In this Book

Chapter 1, Using GPIB1, describes the general guidelines for using GPIB and how to prepare the Test Set for GPIB usage. This chapter includes example programs for controlling the basic functions of the Test Set.

Chapter 2, GPIB Command Guidelines, contains information about sequential and overlapped commands, command syntax, units of measure, and measurement states. A short example program is also presented to familiarize the user with remote operation of the Test Set.

Chapter 3, GPIB Commands, contains command syntax diagrams, equivalent front-panel key commands, IEEE 488.2 Common Commands and triggering commands.

Chapter 4, Advanced Operations, includes information about increasing measurement throughput, status reporting, error reporting, service requests, instrument initialization, and passing control.

Chapter 5, Memory Cards/Mass Storage, describes the types of mass storage (RAM disk, ROM disk, external disk drives, SRAM cards, and ROM cards) and the file system formats (DOS, LIF) available in the Test Set.

Chapter 6, IBASIC Controller, describes how to develop Instrum ent BASIC (IBA-

SIC) programs for use on the Test Set’s built-in IBASIC Controller. Topics discussed are: interfacing to the IBASIC Controller using the serial ports, overview of the three program development methods, entering and editing IBASIC programs, program control using the PROGram Subsystem, and an introduction to writing programs for the TESTS subsystem.

Chapter 7, Programming the Call Processi ng Subsystem, describes how to control the Test Set’s Call Processing Subsystem using the Call Processing Subsystem’s remote user interface. T opics discussed are: accessing the Call Processing Subsystem screens, handling error messages, contro lling program flow using the Call Processing Status Register Group, and how to query data messages received from the mobile station. Example programs are provided showing how to control the Call Processing Subsystem using service requests and register polling.

Error Messages describes the Text Only HP-IB Errors and the Numbered HP-IB Errors. This section also describes other types of error messages that the Test Set displays and where to find more information about those types of error messages.

1. GPIB was formerly called HP-IB for Hewlett-Packard instruments. Some labels

on the instrument may still reflect the former HP

name.

Conventions Used In This Manual

Definition of Test Set

The generic abbreviation "PC" is used to represent computers compatible with the IBM persona l computer (PC) running the M S -DOS

The term "workstation" is used to represent HP Controllers.

The acronym IBASIC is used throughout this manual to refer to Instrument BASIC, a subset of the Rocky Mountain BASIC programming language. The term IBASIC

Controller refers to the Test Set’s built-in IBASIC Controller.

operating system.

9000 Series 200/300 System

A field on the Test Set ’s display is represented in the following manner:

AF Anl In.

A front-panel keycap is represented in the following manner: [TESTS]. When keys are pressed one-at-a-time, they are separated by commas. For

example, [SHIFT], [TESTS] means to press and re lease the [SHIFT] key , then press and release the [TESTS] key.

When keys are pressed simultaneously, they are connected by a plus sign, +. For example, [Alt]+[ P ] means to hold down the [Alt] key and press [ P ].

The generic t erm "Test Set" is used interc hangeably in the manual fo r the Agilent 8920B.

Contents

1 Using GPIB

Overview of the Test Set 22

Getting Started 30

Remote Operation 43

Addressing 45

IEEE 488.1 Remote Interface Message Capabilities 46

Remote/Local Modes 49

2 Methods For Reading Measurement Results

Background 54

BASIC ‘ON TIMEOUT’ Example Program 56

BASIC ‘MAV’ Example Program 60

3 GPIB Command Guidelines

Sequential and Overlapped Commands 66

Guidelines for Operation 67

4 GPIB Commands

GPIB Syntax Diagrams 88

Adjacent Channel Power (ACP) 91

AF Analyzer 93

Contents

AF Generator 1 96

AF Generator 2 Pre-Modulation Filters 97

AF Generator 2/Encoder 98

Configure, I/O Configure 113

Call Processing 119

Decoder 159

Display 163

Measure 165

Oscilloscope 172

Program 177

Save/Recall Registers 178

RF Analyzer 179

RF Generator 181

Radio Interface 182

Spectrum A nalyzer 183

GPIB Only Commands 185

Status 186

System 187

Tests 188

Trigger 191

Contents

Integer Number Setting Syntax 192

Real Number Setting Syntax 193

Multiple Real Number Setting Syntax 194

Number Measurement Syntax 195

Multiple Number Measurement Syntax 197

Equivalent Front-Panel Key Commands 198

IEEE 488.2 Common Commands 226

Common Command Descriptions 241

Triggering Measurements 258

5 Advanced Operations

Increasing Measurement Throughput 268

Status Reporting 275

GPIB Service Requests 329

Instrument Initialization 339

Passing Control 349

6 Memory Cards/Mass Storage

Default File System 360

Mass Storage Device Overview 362

Contents

Default Mass Storage Locations 368

Mass Storage Access 370

DOS and LIF File System Considerations 371

Using the ROM Disk 376

Using Memory Cards 377

Backing Up Procedure and Library Files 383

Copying Files Using IBASIC Commands 384

Using RAM Disk 386

Using External Disk Drives 388

7 IBASIC Controller

Introduction 390

The IBASIC Controller Screen 391

Important Notes for Program Development 393

Program Development 394

Interfacing to the IBASIC Controller using Serial Ports 396

Choosing Your Development Method 409

Method #1. Program Development on an External BASIC Language Computer 411

Method #2. Developing Progra ms on the Test Set Using the IBASIC EDIT Mode 417

Contents

Method #3. Developing Programs Using Word Processor on a PC (Least Preferred) 421

Uploading Programs from the Test Set to a PC 428

Serial I/O from IBASIC Programs 429

PROGram Subsystem 432

The TESTS Subsystem 455

8 Programming the Call Processing Subsystem

Description of the Call Processing Subsystem’s Remote User Interface 462

Using the Call Processing Subsystem’s Remote User Interface 465

Programming the CALL CONTROL Screen 475

Programming the AUTHENTICATION Screen 507

Programming the CALL DATA Screen 516

CALL DATA Screen Message Field Descriptions 521

Programming the CALL BIT Screen 539

CALL BIT Screen Message Field Descriptions 551

Programming the ANALOG MEAS Screen 601

Programming the CALL CONFIGURE Screen 608

Example Programs 612

Contents

9 Error Messages

Index 659

Using GPIB

1. GPIB was formerly called HP-IB for Hewlett-Packard instruments. Some labels on the instrument may still reflect the former HP

name.

Chapter 1, Using GPIB

Overview of the Test Set

The Test Set combines up to 22 separate test instruments and an Inst rument

BASIC (IBAS IC) Controller into one package. All of the Test Set’s functions can be automatically controlled through application programs running on the built-in IBASIC Controller or on an external controller connected through GPIB.

Developing programs for the Test Set is simplified if the programmer has a basic understanding of how the Test Set operates. An overview of the Test Set’s operation is best presented in terms of how information flows through the unit. The simplified block diagrams shown in

depict how instrument control information and measurement result information

are routed among the Test Set’s in strumen ts , instr umen t cont rol hardwar e, bui lt-i n IBASIC controller, and other components.

Figure 1 on page 28 and Figure 2 on page

The Test Set has two operating modes: Manual Control mode and Automatic Control mode. In Manual Control mode the Test Set’s operation is contro lled through the front panel keypad/rotary knob. There are two Automatic Control modes: Internal and External. In Internal Automatic Control mode the Test Set’s operation is controll ed by an ap pli ca ti on program running on the built-in IBASIC Controlle r. In Extern al Automatic Control mode the Test Set’s operation is controlled by an external controller connected to the Test Set through the GPIB interface.

S:\agilent\8920\8920b\PRGGUIDE\BOOK\CHAPTERS\usehpib.fb

Manual Control Mode

The Test Set’s primary instruments are shown on the left side of Figure 1. There are two classes of instruments in the Test Set: signal analyzers (RF Analyzer, AF Analyzer, Oscilloscope, Spectrum Analyzer, Signaling Decoder) and signal sources (RF Generator, AF Generator #1, AF Generator #2/Signaling Encoder). The Test Set’s measurement capability can be extended by adding application specific “top boxes” such as the Agilent 83201A Dual Mode Cellular Adapter.

Since so many instruments are integrated into the Test Set, it is not feasible to have an actual “front panel” for each instrument. Therefore, each instrument’s front panel is maintained in firmware an d is displayed on the CRT whenever the instrument is selected. Only one instrument front panel can be displayed on the CRT at any given time (up to four measurement results can be displayed simultaneously if desired). Just as with stand alone instruments, instrument front panels in the Test Set can contain instrument setting information, measurement result(s), or data input from the DUT.

Chapter 1, Using GPIB

Overview of the Test Set

Using the Test Set in Manual Control mode is very analogous to using a set of bench or rack-mounted test equipment. To obtain a measurement result with a bench or racked system, the desired measurement must be “active.” For example, if an RF power meter is in the bench or racked system and the user wishes to measure the power of an RF carrier they must turn the power meter on, and look at the front panel to see the measurement result. Other instrument s in the system may be turned off but this would not prevent the operator from measuring the RF power.

Conceptually, the same is true for the Test Set. In order to make a measurement or input data from a DUT, the desired measurement field or data field must be “active.” This is done by using the front panel keypad/rotary knob to select the instrument whose front panel contains the desired measurement or data field and making sure that the desired measurement or data field is turned ON.

Figure 1 shows that instrument selection is handled by the To Screen control

hardware which routes the selected instrument’s front panel to the CRT for display. Once an instrument’s front panel is displayed on the CRT, the user can manipulate the i nstrume nt sett ings, such as turni ng a s pecific measurement or data field on or off, using the keypad/rotary knob.

Figure 1 also shows that instrument

setup is handled by the Instrument Control hardware which routes setup information from the front panel to the individual instruments.

A GPIB/RS-232/Parallel Printer interface capability is available in the Test Set. In Manual Control mode this provides the capability of connecting an external GPIB, serial, or parallel printer to the Test Set so that display screens can be printed.

Chapter 1, Using GPIB

Overview of the Test Set

Internal Automatic Control Mode

In Internal Automatic Control mode the Test Set’s operation is controlled by an application program running on the built-in Instrument BASIC (IBASIC) Controller. The built-in controller runs programs written in IBASIC, a subset of the HP

System Controllers. IBASIC is the only programming language supported on the built-in IBASIC Controller.

Similarities Between the Test Set’s IBASIC Controller and Other Single-Tasking Controllers

The architecture of the IBASI C Controll er is similar t o that of other si ngle-tas king instrumentation controllers. Only one program can be run on the IBASIC Controller at any given time. The program is loaded into RAM memory from some type of mass storage device. Five types of mass storage devices are available to the Test Set: SRAM memory cards, ROM memory cards, external disk drives connected to the GPIB i nterface, internal RAM disc, and internal ROM disc. Three types of interfaces are available for connecting to external instruments and equipment: GPIB, RS-232, and 16-bit parallel (available as Opt 020 Radio Interface Card).

BASIC programming language used on the HP® 9000 Series 200/300

Figure 2 shows how information is routed inside the Test Set when it is in Internal

Automatic Control mode. In Manual Control mode certain Test Set resources are dedicated to manual operation. These resources are switched to the IBASIC Controller when an IBASIC prog ram is runni ng. These inc lude the se rial int erface at select code 9, the GPIB int erface at sele ct code 7, the paral lel printer interface at select code 15, and the CRT. In Manual Control mode, front panel information (instrument settings, measurement results, data input from the DUT) is routed to the CRT through the To Screen control hardware. In Internal Automatic Control mode the measurement results and data input from the DUT are routed to the IBASIC Controller through a dedicated GPIB interface. Also, in Internal Automatic Control mode, the CRT is dedicated to the IBASIC Controller for program and graphics display. This means instrument front panels cannot be displayed on the CRT when an IBASIC program is running.

S:\agilent\8920\8920b\PRGGUIDE\BOOK\CHAPTERS\usehpib.fb

Chapter 1, Using GPIB

Overview of the Test Set

Differences Between the Test Set’s IBASIC Controller and Other Single-Tasking Controllers

The IBASIC Controller is unlike other single tasking instrumentation controllers in several ways. First , i t d oes not have a keyboard. This imposes some limitations on creating and editing IBASIC programs directly on the Test Set. In Internal

Automatic Control mode a “virtual” keyboard is available in firmware which allows the operator to enter alphanumeric data into a dedicated input field using the rotary knob. This i s not t he re commended pr ogramming mode for the I BASIC Controller. This feature is provided to allow user access to IBASIC programs for short edits or troubleshooting. Several programming modes for developing IBASIC pro grams to run on the internal IBASIC Controller are discussed in this manual.

Secondly, the IBASIC Controller has a dedicated GPIB interface, select code 8 in

Figure 2, for communi cating with the internal instruments of the Test Set. This

GPIB interface is only ava ilable to the IBASIC Controller. There is no external connector for this GPIB interface. No external instruments may be added to this GPIB interface. The GPIB interfa ce, se le ct code 7 in

Figure 2, is used to interface

the Test Set to external instruments or to an external c ontroller. The dedicate d GPIB interface at select code 8 conforms to the IEEE 488.2 Standard in all respects but one. The difference being that each instrument on the bus does not have a unique address. The Instrument Control Hardware determines which instrument is being addressed through the command syntax. Refer to

“GPIB Commands,”

for a listing of the GPIB command s yntax for the Test Set.

Chapter 4,

Chapter 1, Using GPIB

Overview of the Test Set

External Automatic Control Mode

In External Automatic Control mode the Test Set’s operation is con trolled by an external controlle r co nnec te d to t he Test Set through the GPIB interface. When in External Automatic Control mode the Test Set’s internal confi guratio n is the same as in Manual Control Mode with two exceptions:

1. Configuration and setup commands are received through the external GPIB interface,

select code 7, rather than from the front-panel keypad/rotary knob.

2. The MEASure command is used to obtain measurement results and DUT data through

the external GPIB interface.

Figure 1 on page 28

Control mode.

shows how informat ion i s rout ed i nside the Test Set in Manual

Figure 1 on page 28 also shows that certain Test Set resources are

dedicated to the IBASIC C ontroller (M emory Card, ROM disk, Serial Interface #10) and are not directly accessible to the user in Manual Control Mode. In addition,

Figure 1 on page 28 shows that Serial Interface #9 and Parallel Printer

Interface #15 are accessible as write-only interfaces for printing in Manual Control mode. These same conditions are true when in External Automatic Control mode. If the user wished to access these resources from an external controller, an IBASIC program would have to be run on the Test Set from the external controller.

S:\agilent\8920\8920b\PRGGUIDE\BOOK\CHAPTERS\usehpib.fb

Writing programs for the Test Set

One of the desi gn goals for aut omatic control of the Test Set was that it operat e the same way programmatically as it does manually. This is a key point to remember when developing programs f or the Test Set. The benefit of this approach is that to automate a particular task, one need only figure out how to do the task manually and then duplicate the same process in software. This has several implications when designing and writing programs for the Test Set:

1. In Manual Control mode a measurement must be “active” in order to obtain a

measurement result or input data fro m the DUT. From a programming perspective this means that before attempting to read a measurement result or to input data from the DUT , the desired screen for the measurement result or d ata field must be selected using the DISPlay command and the field must be in the ON state.

2. In Manual Cont rol mode instrument configuration informat ion is not routed th rough the

To Screen control hardware block. From a programming perspective this means that configuration info rmation can be s ent to any des ired inst rument wi thou t havi ng to first select the instrument’s front panel with the DISPlay command.

Chapter 1, Using GPIB

Overview of the Test Set

Keeping these points in mind during program development will minimize program development time and reduce problems encountered when running the program.

Chapter 1, Using GPIB

Overview of the Test Set

FRONT PANEL

SETUP

#10

SERIAL I/F

INFORMATION

PARALLEL

SERIAL I/F

CRT

KEYPAD/

ROTARY KNOB

CONTROL

TO SCREEN

HARDWARE

FRONT

PANEL

INFORMATION

MEMORY CARD

ROM DISK

IBASIC

CONTROLLER

GPIB

TROL HARDWARE

INSTRUMENT CON-

INSTRUMENT

#15

GPIB

PRINTER

RF GEN

AF GEN #1

MEASUREMENT RESULTS AND DUT DATA

AF GEN #2

GEN

SIGNALING

ENCODER

AF ANALYZER

SPECTRUM

ANALYZER

OSCILLOSCOPE

RF ANALYZER

FUNCTION

Figure 1 Manual Control Mode

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SIGNALING

TOP

BOXES

DECODER

Chapter 1, Using GPIB

Overview of the Test Set

FRONT PANEL

TO SCREEN

SETUP

#10

SERIAL I/F

INFORMATION

PARALLEL

SERIAL I/F

CRT

KEYPAD/

ROTARY KNOB

CONTROL

HARDWARE

FRONT

PANEL

INFORMATION

ROM DISK

MEMORY CARD

IBASIC

CONTROLLER

GPIB

TROL HARDWARE

INSTRUMENT CON-

INSTRUMENT

#15

GPIB

PRINTER

RF GEN

AF GEN #1

MEASUREMENT RESULTS AND DUT DATA

GEN

AF GEN #2

FUNCTION

SIGNALING

ENCODER

AF ANALYZER

Figure 2 Internal Automatic Control Mode

TOP

BOXES

SPECTRUM

ANALYZER

OSCILLOSCOPE

DECODER

SIGNALING

RF ANALYZER

Chapter 1, Using GPIB

Getting Started

What is GPIB?

The General Purpose Interface Bus (GPIB) is an implementation of the IEEE

488.1-1987 Standard Digital Interface for Programmable Instrumentation. Incorporation of the GPIB into the Test Set provides several valuable capabilities:

• Programs running in the Test Set’s IBASIC Controller can control all the Test Set’s functions using its internal GPIB. This capability provides a single-instrume nt automated test system. (The Agilent 11807 Radio Test Software utilizes this capability.)

• Programs running in the Test Set’s IBASIC Controller can control other instruments connected to the external GPIB.

• An external controller, connected to the external GPIB, can remotely control the Test Set.

• A GPIB printer, connected to the external GPIB, can be used to print test results and full screen images.

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GPIB Information Provided in This Manual

What Is Explained

• How to configure the Test Set for GPIB operation

• How to make an instrument setting over GPIB

• How to read-back instrument settings over GPIB

• How to make measurements over GPIB

• How to connect external PCs, terminals or controllers to the Test Set

• GPIB command syntax for the Test Set

• IBASIC progr am developmen t

• IBASIC program transfer over GPIB

• Various advanced functions such as, increasing measurement throughput, status reporting, error reporting, pass control, and so forth

Chapter 1, Using GPIB

Getting Started

What Is Not Explained

• GPIB (IEEE 488.1, 488.2) theory of operation

• GPIB electrical specifica ti o ns

• GPIB connector pin functions

• IBASIC programming (other than general guidelines related to GPIB)2

1. Refer to the Tutorial Description of the Hewlett-Packard Interface Bus

(Agilent P/N 5952-0156) for detailed information on GPIB theory and operation.

2. Refer to the Instrument BASIC Users Handbook Version 2.0

(Agilent P/N E2083-90005) for more information on the IBASIC Version 2.0 language.

Chapter 1, Using GPIB

Getting Started

General GPIB Programming Guidelines

The following guidelines shoul d be co nsi dered when developing programs which control the Test Set through GPIB:

• Guideline #1. Avoid using the TX TEST and RX TEST screens.

The RX TEST and TX TEST screens are specifically designed for manual testing of land mobile FM radios and, when displayed, automa tically configure six “priority” fields in the Test Set for this purpose. The priority fields and their preset values are listed in Table 3 on page 33. When the TX TEST screen or the RX TEST screen is displayed, certain priority fields are hidden and are not settable. The priority fields which are hidden are listed in Table 3 on page 33.

NOTE: When the TX TEST screen or the RX TEST screen is displayed, any GPIB commands sent to

the Test Set to change the value of a hidden priority field are ignored. Hidden priority fields on the TX TEST or RX TEST screens are not settable manually or programmatically.

Displaying either of these screens automatically re-configures the 6 “priority” f ields as follows:

1. When entering the RX TEST screen, a. the RF Generator’s Amplitude field, the AFGen1 To field and the AF

Analyzer’s measurement field (measurement displayed in upper, right portion of CRT display) are

• set to their preset values upon entering the screen for the first time since power-up, OR

• set to their preset values if the PRESET key is selected, OR

• set to the last setting made while in the screen

b. the RF Generator Amplitude field and the AFGen1 To field are

• set to their preset values whenever entering the screen, OR

• set to their preset values if the PRESET key is selected

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Chapter 1, Using GPIB

Getting Started

2. When entering the TX TEST screen, a. The AF Anl In field, the De-Emphasis field, the Detector field and the

AF Analyzer Measurement field (measurement displayed in upper, right portion of CRT display) are,

• set to their preset values upon entering the screen for the first time since power-up, OR

• set to their preset values if the PRESET key is selected, OR

• set to the last setting made while in the screen

b. The AF Analyzer AF Anl In, De-Emphasis and Detector fields are,

• set to their preset values whenever entering the screen, OR

• set to their preset values if the PRESET key is selected

Table 3 RX TEST Screen and TX TEST Screen Priority Field Preset Values

Priority

Field

RF Gen

Amplitude

AFGen1 To FM No Audio Out Yes

AF Anl In Audio In Yes FM Demod No

Detector RMS Yes Pk ± Max No De-emphasis Off Yes 750 µsNo AF Analyzer

Measurement

RX TEST

Screen Preset

Value

80 dBm No Off Yes

−

SINAD No Audio Freq No

Field Hidden

On RX TEST

Screen

TX TEST

Screen Preset

Value

Field

Hidden On

TX TEST

Screen

Chapter 1, Using GPIB

Getting Started

• Guideline #2. When developing programs to make measurements always follow this

recommended sequence:

1. Bring the Test Set to its preset state using the front-panel PRESET key. This initial

step allows you to start developing the measurement sequence with most fields in a known state.

2. Make the measurement manually using the front-panel controls of the Test Set.

Record, in sequential order, the screens selected and the settings mad e within each screen. The record of the screens selected and settings made in each screen becomes the measurement procedure.

3. Record the measurement result(s).

In addition to the DISPlay command, the signaling ENCoder and DECoder require further commands to display the correct fields for each signaling mode. For example, DISP ENC;:ENC:MODE 'DTMF'.

4. Develop the program using the measurement procedure generated in step 2. Be sure

to start the programmatic measurement sequence by bringing the Test Set to its preset state using the *RST Common Command. As the measurement procedure requires changing screens, use the DISPlay command to select the desired screen f ollowed by the correct commands to set the desired field(s).

NOTE: When IBASIC programs are running the CRT is dedicated to the IBASIC Controller for

program and graphics display. This means instrument front panels are not displayed on the CRT when an IBASIC program is running. However, the DISPlay <screen > command ca uses all setting and measurement fields in the <screen> to be accessible programmatically. Attempting to read from a screen that has not been made accessible by the DISPlay command will cause

HP-IB Error:-420 Query UNTERMINATED, or HP-IB Error: -113 Undefined header

5. Make sure the desired measurement is in the ON state. This is the preset state for

most measurements. However, if a previous program has set the state to OFF, the measurement will not be available. Attempting to read from a measu remen t field that is not in the ON state will cause HP-IB Error:-420 Query UNTERMINATED.

6. If the trigger mode has been changed, trigger a reading.

NOTE: Triggering is set to FULL SETTling and REPetitive RETRiggering after receipt of the *RST

Common Command. These settings caus e the Test Set t o trigger its elf and a sep arate trigger command is not necessary.

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Chapter 1, Using GPIB

Getting Started

7. Sen d the MEASu re query comman d to in itiate a reading . This wil l place the

measured value into the Test Set’s Output Queue.

NOTE: When making AF Analyzer SINAD, Distortion, Signal to Noise Ratio, AF Frequency, DC

Level, or Current measurements, the measurement type must first be selected using the SELect command. For example, MEAS:AFR:SEL'SINAD' followed by MEAS:AFR:SINAD?

8. Use the ENTER st atement to transfer the measured value to a variable within the

context of the program.

The following example program illustrates how to make settings and then take a reading from the Test Set. This setup takes a reading from the spectrum analyzer

marker after tuning it to the RF generator’s output frequency.

Example

10 Addr=714 20 OUTPUT Addr;"*RST" !Preset to known state 30 OUTPUT Addr;"TRIG:MODE:RETR SING" !Sets single trigger 40 OUTPUT Addr;"DISP RFG" !Selects the RF Gen screen 50 OUTPUT Addr;"AFG1:FM:STAT OFF" !Turns FM OFF 60 OUTPUT Addr;"RFG:AMPL -66 DBM" !Sets RF Gen ampl to -66 dBm 70 OUTPUT Addr;"RFG:FREQ 500 MHZ" !Sets RF Gen freq to 500 MHz 80 OUTPUT Addr;"RFG:AMPL:STAT ON" !Turns RF Gen output ON 90 OUTPUT Addr;"DISP SAN"!Selects Spectrum Analyzer’s screen

100 OUTPUT Addr;"SAN:CRF 500 MHZ" !Center Frequency 500 MHz 110 ! -------------------MEASUREMENT SEQUENCE------------------120 OUTPUT Addr;"TRIG" !Triggers reading 130 OUTPUT Addr;"MEAS:SAN:MARK:LEV?" !Query of Spectrum 140 !Analyzer’s marker level 150 ENTER Addr;Lvl !Places measured value in variable Lvl 160 DISP Lvl!Displays value of Lvl 170 END

The RF Generator’s o utp ut port and th e Spect rum Analyz er’ s input port a re pre set to the RF IN/OUT port. This allows the Spectrum Analyzer to measure the RF Generator with no extern al connect ions. The Spec trum Analyze r marker is alwa ys tuned to the center frequency of the Spectrum Analyzer after preset. With the RF Generator’s ou tput port and Spectrum Analyzer input port both directed t o t he RF IN/OUT port, the two will inter nally couple with 46 dB of gain, giving a measur ed value of approximate ly -20 dBm. While not a no rmal mode of ope ration th is setup is convenient for demonstration since no external cables are required. This also illustrates the value of starting from the preset state since fewer programming commands are required.

Chapter 1, Using GPIB

Getting Started

• Guideline #3. Avoid program hangs.

If the program stops or “han gs up” when tryi ng to ENTER a measured valu e, it is most likely that the desired measurement field is not available. There are several reasons that can happen:

1. The screen where the measurement field is located has not been DISPlayed before

querying the measurement field.

2. The measurement is not turned ON.

3. The squelch control is set too high. If a measurement is turned ON but is not

available due to the Squelch setting, the measurement field contains four dashes (- - - -). This is a valid state. The Test Set is waiting for a signal of sufficient strength to unsquelch the receiver before making a measurement. If a measurement field which is squelched is queried the Test Set will wait indefinitely for the receiver to unsquelch and return a measured value.

4. The RF Analyzer’s Input Port is set to ANT (antenna) while trying to read TX

power. TX power is not measurable with the Input Port set to ANT. The TX power measurement field will display four dashes (- - - -) indicating the measurement is unavailable.

5. The input signal to the Test Set is very unstable causing the Test Set to continuously

autorange. This condition will be apparent if an attempt is made to make the measurement manually.

6. Trigger mode has been set to single trigger (TRIG:MODE:RETRig SINGle) and a

new measurement cycle has not been triggered before attempting to read the measured value.

7. The program is attempting to make an FM de viation or AM depth measurement

while in the RX TEST screen. FM or AM measurements are not available in the RX TEST screen. FM or AM measurements are made from the AF Analyzer screen b y setting the AF Anl In field to FM or AM Demod.

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Chapter 1, Using GPIB

Getting Started

• Guideline #4. Use single quotes and spaces properly. The syntax diagrams in Chapter 4, “GPIB Commands,” show where single quotes

are needed and where spaces are needed.

Example

OUTPUT 714;"DISP<space>AFAN" OUTPUT 714;"AFAN:DEMP<space>’Off’"

Improper use of single quotes and spaces will cause, HP-IB Error:-103 Invalid Separator

• Guideline #5. Ensure that settable fields are active by using the STATe ON command. When making settings to fields that can be turned OFF with the STATe ON/OFF

command (refer to the Chapter 4, “GPIB Commands ,”), make sure the STATe is ON

if the program uses that field. Note that if the STATe is OFF, just setting a numeric value in the field will not change the STATe to ON. This is different than front-panel operation whereby the process of selecting the field and entering a value automatically sets the ST ATe to ON. Programmatically , fields must be explicitly set to the ON state if they are in the OFF state.

For example, the following command li ne woul d set a new AMPS ENCod er SAT tone deviation and then turn on the SAT tone (note the use of the ; to back up one level in the command hierarchy so that more than one command can be executed in a single line):

Example

OUTPUT 714;"ENC:AMPS:SAT:FM 2.1 KHZ;FM:STAT ON"

To just turn on the S AT tone without changing the current setting the following commands would be used:

OUTPUT 714;"ENC:AMPS:SAT:FM:STAT ON"

Chapter 1, Using GPIB

Getting Started

• Guideline #6. Numeric values are returned in GPIB Units or Attribute Units only.

When querying measurements or settings through GPIB, the Test Set always returns numeric values in GPIB Units or Attribute Units, regardl ess of the current Display Units setting. GPIB Units, Attribute Units and Display Units determine the units-ofmeasure used for a measurement or setting, for example, Hz, Volts, Watts, Amperes, Ohms. Refer to “Specifying Units-of-Measure for Settings and Measurement

Results” on page 71 for further information.

For example, if the Test Set’s front panel is displaying TX Frequency as 835.02 MHz, and the field is queried through GPIB, the value returned will be 835020000 since the GPIB Units for frequency are Hz. Note that changing Display Units will not change GPIB Units or Attribute Units. Note also that setting the value of a numeric field through GPIB can be done using a variety of units-of-measure. The GPIB Units or Attribute Units for a queried value can always be determined us ing the :UNITs? command or :AUNits? command respectively (refer to “Number Measurement

Syntax” on page 195 or “Multiple Number Measurement Syntax” on page 197,

for command syntax).

Control Annunciators

The letters and symbols at the top right corner of the display indicate these conditions:

• R indicates the Test Set is in remote mode. The T est Set can be put into the remote mode by an external controller or by an IBASIC program running on the built-in IBASIC controller.

• L indicates that the Test Set has been addressed to Listen.

• T indicates that the Test Set has been addressed to Talk.

• S indicates that the Test Set has sent the Require Service message by setting the Service Request (SRQ) bus line true. (See “Status Reporting” on page 275.)

• C indicates that the Test Set is currently the Active Controller on the bus.

• * indicates that an IBASIC program is running.

• ? indicates that an IBASIC program is waiting for a user response.

• - indicates that an IBASIC program is paused.

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Preparing the Test Set For GPIB Use

1. If other GPIB devices are in the system, attach a GPIB cable from the Test Set’s rear-

panel GPIB connector to any one of the other devices in the test system.

2. Access the I/O CONFIGURE screen and perform the following steps: a. Set the Test Set’s GPIB address using the HP-IB Adrs field. b. Set the Test Set’s GPIB Controller capability using the Mode field.

• Talk&Listen configures the Test Set to not be the System Controller. The Test Set has Active Controller capability (take control/pass control) in this mode. Use this setting if the Test Set will be controlled through GPIB from an external controller.

• Control configures the Test Set to be the System Controller. Use this setting if the Test Set will be the only controller on the GPIB. Selecting the Control mode automatically makes the Test Set the Active Controller.

Chapter 1, Using GPIB

Getting Started

NOTE: Only one System Controller can be configu red in a GPIB system. R efer to “Passin g Contr ol”

on page 349 for further information.

3. If a GPIB printer is or will be connected to the Test Set’s rear panel GPIB connector

then,

a. access the PRINT CONFIGURE screen. b. select one of the supported GPIB printer models using the Model field. c. set the Printer Port field to HP-IB.

d. set the printer address using the Printer Address field.

Chapter 1, Using GPIB

Getting Started

Using the GPIB with the Test Set’s built-in IBASIC Controller

The Test Set has two GPIB interfaces, an internal-only GPIB at select code 8 and an external GPIB at select code 7. The GPIB at select code 8 is only available to the built-in IBASIC Controller and is used exclusively for communication between the IBASIC Control ler and t he Test Set. The GPIB at select code 7 serves three purposes:

1. It allows the Test Set to be controlled by an external controller

2. It allows the Test Set to print to an external GPIB printer

3. It allows the built-in IBASIC Controller to control external GPIB devices

IBASIC programs running on the Test Set’s IBASIC Controller must use the internal-only GPIB at sel ect code 8 to c ontrol the Test Set. IBASIC programs would use the external GPIB at select code 7 to control GPIB devices connected to the rear panel GPIB connector.

NOTE: Refer to “Overview of the Test Set” on page 22 for a detailed explanation of the Test Set’s

architecture.

When using a BASIC language Workstation with an GPIB interface a t sele ct cod e 7 to control the Test Set, GPIB commands would look like this:

Example

! This command is sent to the Test Set at address 14. OUTPUT 714;"*RST" ! This command is sent to another instrument whose address is 19. OUTPUT 719;"*RST"

When executing the same commands on the Test Set’s IBASIC Controller, the commands would look like this:

Example

OUTPUT 814;"*RST" ! Command sent to internal-only GPIB at select code 8,

! Test Set’s address does not change OUTPUT 719;"*RST" ! Command sent to external GPIB at select code 7, ! other instrument’s address does not change.

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Basic Programming Examples

The following simple examples illustrate the basic approach to controlling the Test Set through the GPIB. The punctuation and command syntax used for these examples is given in

The bus address 714 used in the following BASIC language examples assumes a GPIB interface at select code 7, and a Test Set GPIB address of 14. All examples assume an external controller is being used.

To Change a Field’s Setting over GPIB

1. Use the DISPlay command to access the screen containing the field whose setting is to

be changed.

2. Make the desired setting using the proper command syntax (refer to Chapter 4, “GPIB

Commands,” for p roper syntax).

The following example makes several instrument setting changes:

Chapter 1, Using GPIB

Getting Started

Chapter 4, “GPIB Commands.”.

Example

OUTPUT 714;"DISP RFG" !Display the RF Generator screen. OUTPUT 714;"RFG:FREQ 850 MHZ" !Set the RF Gen Freq to 850 MHz. OUTPUT 714;"RFG:OUTP ’DUPL’"!Set the Output Port to Duplex. OUTPUT 714;"DISP AFAN"!Display the AF Analyzer screen. OUTPUT 714;"AFAN:INP ’FM DEMOD’"!Set the AF Anl In to FM Demod.

To Read a Field’s Setting over GPIB37

1. Use the DISPlay command to access the screen containing the field whose setting is to

be read.

2. Use th e Query form of the syntax for that field to place the setting value into the Test

Set’s output buffer.

3. Enter the value into the correct variable type within the program context (refer to

Chapter 4, “GPIB Commands,”, for proper variable type).

Chapter 1, Using GPIB

Getting Started

The following example reads several fields.

Example

OUTPUT 714;"DISP AFAN"!Display the AF Analyzer screen. OUTPUT 714;"AFAN:INP?"!Query the AF Anl In field ENTER 714;Af_input$ !Enter returned value into a string ariable. OUTPUT 714;"DISP RFG"!Display the RF Generator screen OUTPUT 714;"RFG:FREQ?"!Query the RF Gen Frequency field. ENTER 714;Freq !Enter the returned value into a numeric variable

NOTE: When querying measurements or s ettings through GPIB, the Test Set always returns numeric

values in GPIB Units or Attribute Units, regardless of the current Display Units setting. Refer to “GPIB Units (UNITs)” on page 74 and “Attribute Units (AUNits)” on page 77 for further information.

To Make a Simple Measurement

The basic method for making a measurement is very similar to the method used to read a field setting.

1. Use the DISPlay command to access the screen containing the desired measurement.

2. Use the MEASure form of the syntax for that measurement to place the measured value

into the Test Set’s output buffer.

3. Enter the value into the correct variable type within the program context (refer to

Chapter 4, “GPIB Commands,” for proper variable type).

The following example measures the power of an RF signal.

Example

!Display the RF Analyzer screen. OUTPUT 714;"DISP RFAN" !Measure the RF power and place result in output buffer. OUTPUT 714;"MEAS:RFR:POW?" !Enter the measured value into a numeric variable. ENTER 714;Tx_power

The above example is very simple and is desi gned to demonstrate the fundamental procedure for obtaining a measurement result. Many other factors must be considered when designing a measurement procedur e, such as instrume nt settings, signal routing, settling time, filtering, triggering and measurement speed.

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Remote Operation

Chapter 1, Using GPIB

Remote Operation

The Test Set can be operate d re mo te ly through the General Purpose In ter face Bus (GPIB). Except as otherwise noted, the Test Set complies with the IEEE

488.1-1987 and IEEE 48 8.2-1987 Standards . Bus compati bility, programming and

data formats are described in the following sections. All front-panel functions, except those listed in

Table 4, are programmable

through GPIB.

Table 4 Non-Programmable Front Panel Functions

Function Comment

ON/OFF Power Switch Volume Control Knob Squelch Control Knob The position of the Squelch Control knob cannot be programmed. How-

ever squelch can be programmed to either the Open or Fixed position.

Refer to the Test Set’s User’s Guide for more information. Cursor Control Knob SHIFT Key CANCEL Key YES Key NO Key ENTER Key Backspace (left-arrow) Key PREV Key HOLD ( SHIFT, PREV Keys) PRINT ( SHIFT, TESTS Keys) ADRS ( SHIFT, LOCAL Keys) ASSIGN ( SHIFT, k4 Keys) RELEASE ( SHIFT, k5 Keys)

Chapter 1, Using GPIB

Remote Operation

Remote Capabilities

Conformance to the IEEE 488.1-1987 Standard

For all IEEE 488.1 functions implemented, the Test Set adheres to the rules and procedures as outlined in that Standard.

Conformance to the IEEE 488.2-1987 Standard

For all IEEE 488.2 functions implemented, the Test Set adheres to the rules and procedures as outlined in that Standard with the exception of the *OPC Common Command. Refer to the *OPC Common Command description.

IEEE 488.1 Interface Functions

The interface functions that the Test Set implements are listed in Table 5.

Table 5 Test Set IEEE 488.1 Interface Function Capabilities

Function Capability

Talker T6: No Talk Only Mode Extended Talker T0: No Extended Talker Capability Listener L4: No Listen Only Mode Extended Listener LE0: No Extended Listener Capability Source Handshake SH1: Complete Capability Acceptor Handshake AH1: Complete Capability Remote/Local RL1: Complete Capability Service Request SR1: Complete Capability Parallel Poll PP0 : No Parallel Poll Capability Device Clear DC1: Complete Capability Device Trigger DT1: Complete Capability Controller C1: System Controller

C3: Send REN C4: Respond to SRQ C11:No Pass Control to Self, No Parallel Poll

Drivers E2: Tri-State Drivers

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Addressing

Factory Set Address

Extended Addressing

Chapter 1, Using GPIB

Addressing

The Test Set’s GPIB address is set to decimal 14 at the factory. The address can be changed by following t he instructions in

Extended addressing ( secondary command) capa bility i s not implemen ted in the Test Set.

“Setting the Test Set’s Bus Address” on page

Multiple Addressing

Multiple addressing cap ability is not implemente d in the Test Set.

Setting the Test Set’s Bus Address

The Test Set’s GPIB bus address is set u sin g the HP-IB Adrs field which is located on the I/O CONFIGURE screen. To set the GPIB bus address; select the I/O CONFIGURE screen and position the cursor next to the address can be set fr om decimal 0 t o 30 using the numeric DAT A ke ys, or by pus hing and then rotating the Cursor Contr ol knob. Ther e ar e no DIP swi tc hes f or se tt ing the GPIB bus address in the Test Set. The new setting is retained when the Test Set is turned off.

Displaying the Bus Address

The Test Set’s GPIB bus address can be displayed by pressing and releasing the SHIFT key, then the LOCAL key. The address is displayed in the upper left-hand corner of the display screen.

HP-IB Adrs field. The

Chapter 1, Using GPIB

IEEE 488.1 Remote Interface Message Capabilities

The remote interface message capabilities of the Test Set and the associated IEEE

488.1 messages and control lines are listed in

Table 6 Test Set IEEE 488.1 Interface Message Capability

Message Type Implemented Response

Table 6.

IEEE

488.1

Message

Data Yes All front-panel functions, except those listed in Table 4

on page 43, are programmable. The Test Set can send sta-

tus byte, message and setting inform ation. All measure-

ment results (except dashed “- - - -” displays) and error messages are available through the bus.

Remote Yes Remote programming mode is entered when the Remote

Enable (REN) bus control line is true and the Test Set is addressed to listen. The R annunciator will appear in the upper-right corner of the display screen when the Test Set is in remote mode. All front-panel keys are disabled (except for the LOCAL key, POWER switch, Volume control and Squelch control knobs). When the Test Set enters remote mode the output signals and internal settings remain unchanged, except that triggering is reset to the state it was last set to in remote mode (Refer to “Trigger-

ing Measurements” on page 258).

Local Yes The Test Set returns to local mode (full front-panel con-

trol) when either the Go To Local (GTL) bus command is received, the front-panel LOCAL key is pressed or the REN line goes false. When the Test Set returns to local mode the output signals and internal settings remain unchanged, except that triggering is reset to TRIG:MODE:SETT FULL;RETR REP. The LOCAL key will not function if the Test Set is in the local lockout mode.

DAB END MTA MLA OTA

REN MLA

GTL MLA

Local Lockout Yes Local Lockout disables all front-panel keys including the

LOCAL key. Only the System Controller or the POWER switch can return the Test Set to local mode (front-panel control).

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LLO

IEEE 488.1 Remote Interface Message Capabilities

Table 6 Test Set IEEE 488.1 Interface Message Capability (Continued)

Message Type Implemented Response

Chapter 1, Using GPIB

IEEE

488.1

Message

Clear Lockout/ Set Local

Service Request Yes The Test Set sets the Service Request (SRQ) bus line true

Status Byte Yes The Test Set responds to a Serial Poll Enable (SPE) bus

Status Bit No The Test Set does not have the capability to respond to a

Clear Yes This message clears the Input Buffer and Output Queue,

Yes The Test Set returns to local mode (front-panel control)

and local lockout is cleared when the REN bus control line goes false. When the Test Set returns to local mode the output signals and internal settings remain unchanged, except that triggering is set to TRIG:MODE:SETT FULL;RETR REP.

if any of the enabled conditions in the Status Byte Register, as defined by the Service R equest Enable Register, are true.

command by sending an 8-bit status byte when addressed to talk. Bit 6 will be true, logic 1, if the Test Set has sent the SRQ message

Parallel Poll.

clears any commands in process, puts the Test Set into the Operation Complete idle state and prepares the Test Set to receive new commands. The Device Clear (DCL) or Selected Device Clear (SDC) bus commands

REN

SRQ

SPE SPD STB MTA

PPE PPD PPU PPC IDY

DCL SDC MLA

• do not change any settings or stored data (except as noted previously)

• do not interrupt front panel I/O or any Test Set operation in progress (except as noted previously)

• do not change the contents of the Status Byte Register (other than clearing the MAV bit as a consequence of clearing the Output Queue).

The Test Set responds equally to DCL or SDC bus commands.

Chapter 1, Using GPIB

IEEE 488.1 Remote Interface Message Capabilities

Table 6 Test Set IEEE 488.1 Interface Message Capability (Continued)

Message Type Implemented Response

IEEE

488.1

Message

Trigger Yes If in remote programming mode and addressed to listen,

the Test Set makes a triggered measurement following the

GET

MLA trigger conditions currently in effect in the instrument. The Test Set responds equally to the Group Execute Trigger (GET) bus command or the *TRG Common Command.

Take Control Yes The Test Set begins to act as the Active Controller on the

bus.

TCT

MTA

Abort Yes The Test Set stops talking and listening IFC

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Remote/Local Modes

Remote Mode

In Remote mode all front-panel keys are disabled (except for the LOCAL key, POWER switch, Volume control and Squelch control). The LOCAL key is only disabled by the Local Lockout bus command. When in Remote mode and addressed to Listen the Test Set responds to the Data, Remote, Local, Clear (SDC), and Trigger messages. When the Test Set is in Remote mode, the annunciator will be displayed in the upper right corner of the display screen and triggering is set to the sta te it was last set to in Remote mode (if no previous setting, the default is FULL SETTling and REPetitive RETRiggering). When the Test Set is being addressed to Listen or Talk the displayed in the upper-right corner of the display screen.

Chapter 1, Using GPIB

Remote/Local Modes

L or T annunciators will be

Local Mode

In Local mode the Test Set’s front-panel controls are fully operational. The Test Set uses FULL SETTling and REPetiti ve RETRiggering in Lo cal mode. When the Test Set is being addressed to Listen or Talk the displayed in the upper-right corner of the display screen.

Remote or Local Mode

When addressed to Talk in Remote or Local mode, the Test Set can issue the Data and Status Byte messages and respond to the Take Control message. In addition the Test Set can issue the Ser vice Re quest Mes sage (S RQ). Reg ardles s of whet her it is addressed to talk or listen, the Test Set will respond to the Clear (DCL), Local Lockout, Clear Lockout/Set Local, and Abort messages.

L or T annunciators will be

Chapter 1, Using GPIB

Remote/Local Modes

Local To Remote Transitions

The Test Set switches from Local to Remote mode upon receipt of the Remote message (REN bus line true and Test Set is addressed to listen). No instrument settings are changed by the transition from Local to Remote mode, but triggering is set to the state it was las t set to in Remo te mode (if no p revious setting, the default is FULL SETTling and REPetitive RETRiggering). The the upper-right corner of the display is turned on.

When the Test Set makes a transition from local to remote mode, all currently active measurements are flagged as invalid causing any currently available measurement results to become unavailable. If the GPIB trigger mode is :RETR REP then a new measurement cycle is started and measurement results will be available for all active measurements when valid results have been obtained. If the GPIB trigger mode is :RETR SING then a measurement cycle must be started by issuing a trigger event. Refer to

page 258

R annunciator in

“Triggering Measurements” on

for more inform ation.

Remote To Local Transitions

The Test Set switches from Remote to Local mode upon receipt of the Local message (Go To Local bus message is sent and Test Set is addressed to listen) or receipt of the Clear Lockout/Set Local message (REN bus line false). No instrument settings a re change d by the tr ansit ion fr om Remote to Loca l mode, but triggering is reset to FULL SETTling and REPetitive RETRiggering. The annunciator in the upper right corner of the display is turned off.

If it is not in Local Lockout mode the Test Set switches from Remote to Local mode whenever the front-panel LOCAL key is pressed.

If the Test Set was in Local Lockout mode when the Local message was recei ved, front-panel cont ro l is returned, but Local Lockout mode is not cleared. Unl ess the T est Set re ceive s the Cl ear Lock out/Se t Local message , the Test Set will still be in Local Lockout mode the next time it goes to the Remote mode.

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Chapter 1, Using GPIB

Remote/Local Modes

Local Lockout

The Local Lockout mode disables the front-panel LOCAL key and allows return to Local mode only by commands f rom the Sys tem Contr oller (Clear Lockout /Set Local message).

When a data transmission to the Test Set is interrupted, which can happen if the LOCAL key is pressed, the data bei ng t ra nsmitted may be lost. This can leave the Test Set in an unknown state. The Local Lockout mode prevents loss of data or system control due to someone unintentionally pressing front-panel keys.

NOTE: Return to Local mode can also be accomplished by setting the POWER switch to OFF and

back to ON. However, returning to Local mode in this way has the following disadvantages:

1. It defeats the purpose of the Local Lockout mode in that the Active Controller will lose

control of the test set.

2. Instrument configuration is reset to the power up condition thereby losing the

instrument configuration set by the Active Controller.

Clear Lockout/Set Local

The Test Set returns to Local mode when it receives the Clear Lockout/Set Local message. No instrument set ting s are c hanged by the t ransi tion f rom Remote mod e with Local Lockout to Local mode but triggering is reset to FULL SETTling and REPetitive RETRiggering.

Chapter 1, Using GPIB

Remote/Local Modes

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Methods For Reading Measurement Results

Chapter 2, Methods For Reading Measurement Results

Background

One of the most common remote user interface operations performed on an Test Set is to query and read a m easurement result. Generally, this operation is accomplished by sending the query command to the Test Set, followed immediately by a request to read the requested measurement result. Using Hewlett-Packard Rocky Mou nta in BASIC (RMB) language, this operati on woul d be written using the OUTPUT and ENTER command as follows:

OUTPUT 714;"MEAS:RFR:POW?" ENTER 714;Power

Using this programming structure, the control program will stay on the ENTER statement until i t is satisfied - that i s - until the Test Set has retur ned the requested measurement result. This structure works correctly as long as the Test Set returns a valid measurement result. If, for some reason, the Test Set does not return a

measurement result, the control program becomes “hung” on the ENTER statement and program execution effectively stops.

In order to prevent the control program from becoming “hung” programmers usually enclose the operati on with some form of t imeout func tion. The f orm of the timeout will of course depend upon the programming language being used. The purpose of the timeout is to specify a fixed amount of time that the control program will wait for the Test Set to return the reque sted re sult. Aft er this time has expired the control program will abandon the ENTER statement and try to take some corrective action to regain control of the Test Set.

If the control program does not send the pr oper commands in the prop er seque nce when trying to regain control of the Test Set, unexpected operation will result . When this condition is encountered, power must be cycled on the Test Set to regain control.

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Chapter 2, Methods For Reading Measurement Results

Background

This situation can be avoided entirely by:

1. sending a Selected Device Clear (SDC) interface message to put the Test Set’s GPIB

subsystem into a known state.

2. sending a command to terminate the requested measurement cycle.

These comman ds issued in th is order will allow the control program to regain control of the Test Set. Any other sequence of commands will r esult i n unexpect ed operation.

The following programs demonstrate a recommended technique for querying and entering data from the Test Set. This technique will prevent the Test Set from

getting into a ‘hung’ state such that power must be cycled on the Test Set to regain manual or programmatic control.

There are a variety of programming constructs which can be used to implement this technique. In the programming examples presented, a function call is implemented which returns a numeric measurement result. The function call has two pass parameters; the query command (passed as a quoted string) and a timeout value (passed as a integer number).

The time-out value represents how long you want to wait, in seconds, for the Test Set to return a valid measurement result. If a valid measurement result is not returned by the Test Set within the time-out value, the function returns a very large number. The calling program can check the value and take appropriate action.

The program examples are written so as to be self-explanatory. In practice, the length of: v ariable names, line labels, func tion names, etc., will be implementation depe nden t.

Chapter 2, Methods For Reading Measurement Results

BASIC ‘ON TIMEOUT’ Example Program

HP® BASIC ‘ON TIMEOUT’ Example Program

The following example program demonstrates a recommended technique which can be utilized in situations where a measurement result timeout value of 32.767 seconds or less is adequate. In the Agilent RMB language, the timeout parameter for the ON TIMEOUT command has a maximum value of 32.767 seconds. If a timeout value of greater than 32.767 seconds is req uired refer to the

BASIC

The measurement result timeout value is defined to mean the amount of time the control program is willing to wait for the Test Set to return a valid measurement result to the control program.

Lines 10 thru 230 in this example set up a measurement situation to demonstrate the use of the recommended technique. The recommended technique is exampled in the Measure Function.

‘MAV’ Bit Example Program.

HP®

NOTE: Lines 50 and 60 sh ould be included in the beginn ing of a ll cont rol pro gram. T hese l ines ar e

required to ensure that the Test Set is properly reset. This covers the case where the program was previously run and was stopped with the Test Set in an error condition.

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Chapter 2, Methods For Reading Measurement Results

BASIC ‘ON TIMEOUT’ Example Program

10 COM /Io_names/ INTEGER Inst_addr,Bus_addr 20 CLEAR SCREEN 30 Inst_addr=714 40 Bus_addr=7 50 CLEAR Inst_addr 60 OUTPUT Inst_addr;"TRIG:ABORT" 70 OUTPUT Inst_addr;"*RST" 80 OUTPUT Inst_addr;"DISP RFAN" 90 ! 100 ! Execute a call to the Measure function with a request to measure RF 110 ! power. The time out value is specified as 10 seconds. The value 120 ! returned by the function is assigned to the variable Measure_result. 130 ! 140 Measure_result=FNMeasure("MEAS:RFR:POW?",10) 150 ! 160 ! Check the result of the function call. 170 ! 180 IF Measure_result=9.E+99 THEN 190 PRINT "Measurement failed." 200 ELSE 210 PRINT "Power = ";Measure_result 220 END IF 230 END 240 !*********************************************************** 250 ! Recommended Technique: 260 !*********************************************************** 270 DEF FNMeasure(Query_command$,Time_out_value) 280 COM /Io_names/ INTEGER Inst_addr,Bus_addr 290 DISABLE 300 ON TIMEOUT Bus_addr,Time_out_value RECOVER Timed_out 310 OUTPUT Inst_addr;"TRIG:MODE:RETR SING;:TRIG:IMM" 320 OUTPUT Inst_addr;Query_command$ 330 ENTER Inst_addr;Result 340 OUTPUT Inst_addr;"TRIG:MODE:RETR REP" 350 ENABLE 360 RETURN Result 370 Timed_out:! 380 ON TIMEOUT Bus_addr,Time_out_value GOTO Cannot_recover 390 CLEAR Inst_addr 400 OUTPUT Inst_addr;"TRIG:ABORT;MODE:RETR REP" 410 ENABLE 420 RETURN 9.E+99 430 Cannot_recover:! 440 DISP "Cannot regain control of Test Set." 450 STOP 460 FNEND

Chapter 2, Methods For Reading Measurement Results

BASIC ‘ON TIMEOUT’ Example Program

Comments for Recommended Routine

Table 7 Comments for Measure Function from ON TIMEOUT

Example Program

Program Line

Number

290

300

310

Comments

Send a Selected Device Clear (SDC) to the Test Set to put the GPIB subsystem into a known state. This allows the control program to regain programmatic control of the Test Set if it is in an error state when the program begins to run.

Command the Test Set to abort the currently executing measurement cycle. This will force the Test Set to stop waiting for any measurement results to be available from measurements which may be i n a n invalid state when the program begi ns to run.

Turn event initiated branches off (except ON END, ON ERROR and ON TIMEOUT) to ensure that the Measure function will not be exited until it is finished.

Set up a timeo ut for any I/O a ctivity on th e GPIB. This will allow the function to recover if the bus hangs for any reason.

Set the triggering mode to singl e fol lowed by a tr igger immediat e command. Thi s ensures that a new measurement cycle will be started when the TRIG:IMM command is sent. This sequence, that is: set to single trigger and then send a trigger command, guarantee s th at t he measurement result returned to the ENTE R statement will accurately reflect the state of the DUT when the TRIG:IMM command was sent. The ’IMM’ keyword is optional.

320 330 340

Send the query command passed to the Measure function to the Test Set. Read the measurement result. Set the trigger mode to repetitive retriggering. Setting the trigger mode to

repetitive will be implementation dependent.

350

Re-enable event initiated branching. If any event initiated branches were logged while the Measure function was executing they will be executed when system priority permits.

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Chapter 2, Methods For Reading Measurement Results

Table 7 Comments for Measure Function from ON TIMEOUT

Example Program (Continued)

BASIC ‘ON TIMEOUT’ Example Program

Program Line

Number

360 370

380

390

400

410

Comments

Exit the Measure functio n and return the result value. The following lines of code handle the case where the request for a measurement

result has timed out. Set up a timeout for any I/O activity on the GPIB while the control program is

trying to regain control of the Test Set. This will allow the function to gracefully stop program execution if the control program cannot regain control of the Test Set. This timeout should only occur if there is some type of hardware failure, either in the Test Set or the externa l controller, which prevents them from communicating via GPIB.

Send a Selected Device Clear (SDC) to the Test Set to put the GPIB subsystem into a known state. This allows the control program to regain programmatic control of the Test Set.

Command the Test Set to abort the currently executing measurement cycle. Set the trigger mode back to repetitive retriggering. S etting the Test Set back to repetitive retriggering will be implementation dependent.

Re-enable event initiated branching. If any event initiated branches were logged while the Measure function was executing they will be executed when system priority permits.

420

Exit the Measure function and return a result value of 9.E+99.

430 The following lines of code handle the case where the control program cannot

regain control of the Test Set. The actions taken in this section of the code will be implementation dependent. For the example case a message is displayed to the operator and the program is stopped.

440 Display a message to the operator that the control program cannot regai n control

of the Test Set.

450 Stop execution of the control program.

Chapter 2, Methods For Reading Measurement Results

BASIC ‘MAV’ Example Program

HP® BASIC ‘MAV’ Example Program

The following Agilent RMB example program demonstrates a technique which can be used in situations where a 32.767 measurement result timeout value is not adequate.

Measurement result timeout value is defined to mean the amount of time the control program is willing to wait for the Test Set to return a valid measurement result to the control program.

The technique uses the MAV (Message Available) bit in the Test Set’s GPIB Status Byte to determine when there is data in the Ou tput Queue. A pol ling loop is used to query the Status byte. The timeout duration for returning the measurement result is han dled by t he po lling l oop. An GPIB inter face ac tivity timeout is a lso set up to handle time-outs resulting from problems with the GPIB interface.

Lines 10 thru 230 in this example set up a measurement situation to demonstrate the use of the recommended technique. The recommended technique is exampled in the Measure Function.

NOTE: Lines 50 and 60 sh ould be included in the beginn ing of a ll cont rol pro gram. T hese l ines ar e

required to ensure that the Test Set is properly reset. This covers the case where the program was previously run and was stopped with the Test Set in an error condition.

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Chapter 2, Methods For Reading Measurement Results

BASIC ‘MAV’ Example Program

10 COM /Io_names/ INTEGER Inst_addr,Bus_addr 20 CLEAR SCREEN 30 Inst_addr=714 40 Bus_addr=7 50 CLEAR Inst_addr 60 OUTPUT Inst_addr;"TRIG:ABORT" 70 OUTPUT Inst_addr;"*RST" 80 OUTPUT Inst_addr;"DISP RFAN" 90 ! 100 ! Execute a call to the Measure function with a request to measure RF 110 ! power. The time out value is specified as 50 seconds. The value 120 ! returned by the function is assigned to the variable Measure_result. 130 ! 140 Measure_result=FNMeasure("MEAS:RFR:POW?",50) 150 ! 160 ! Check the result of the function call. 170 ! 180 IF Measure_result=9.E+99 THEN 190 PRINT "Measurement failed." 200 ELSE 210 PRINT "Power = ";Measure_result 220 END IF 230 END 240 !*********************************************************** 250 ! Recommended Technique: 260 !*********************************************************** 270 DEF FNMeasure(Query_command$,Time_out_value) 280 COM /Io_names/ INTEGER Inst_addr,Bus_addr 290 DISABLE 300 ON TIMEOUT Bus_addr,5 GOTO Timed_out 310 OUTPUT Inst_addr;"TRIG:MODE:RETR SING;:TRIG:IMM" 320 OUTPUT Inst_addr;Query_command$ 330 Start_time=TIMEDATE 340 REPEAT 350 WAIT .1 360 Status_byte=SPOLL(Inst_addr) 370 IF BIT(Status_byte,4) THEN 380 ENTER Inst_addr;Result 390 OUTPUT Inst_addr;"TRIG:MODE:RETR REP" 400 ENABLE 410 RETURN Result 420 END IF 430 UNTIL TIMEDATE-Start_time>=Time_out_value 440 Timed_out:! 450 ON TIMEOUT Bus_addr,5 GOTO Cannot_recover 460 CLEAR Inst_addr 470 OUTPUT Inst_addr;"TRIG:ABORT;MODE:RETR REP" 480 RETURN 9.E+99 490 Cannot_recover: ! 500 DISP "Cannot regain control of Test Set." 510 STOP 520 FNEND

Chapter 2, Methods For Reading Measurement Results

BASIC ‘MAV’ Example Program

Comments for Recommended Routine

Table 8 Comments for Measure Function from MAV Example Program

Program Line

Number

290

300

310

Comments

Turn event initiated branches off (except ON END, ON ERROR and ON TIMEOUT) to ensure that the Measure function will not be exited until it is finished.

Set up a 5 second timeout for any I/O activity on the GPIB. This will allow the function to recover i f the bus hangs for any reason. The le ngt h of the timeout will be implementation dependent.

Set the triggering mode to singl e fol lowed by a tr igger immediat e command. Thi s ensures that a new measurement cycle will be started when the TRIG:IMM command is sent. This s equence , that is: set t o singl e tri gger a nd the n send t rigger command, guarantee s that the measurement result returned to the ENTER statement will accurately reflect the state of the DUT when the TRIG:IMM command was sent. The ’IMM’ keyword is optional.

320 330

Send the query command passed to the Measure function to the Test Set. Establish a start time against which to compare the measurement result timeout

value passed to the Measure function.

340 350

Start the status byte polling loop. Allow the Test Set some time (100 milliseconds) to process the measurement.

When polling the Test Set the polling loop must give the Test Set time to process the requested measurement. Since GPIB command processing has a higher system priority within the Test Set than measurement functions, constantly sendin g GPIB commands will result in longer measurement times.

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Chapter 2, Methods For Reading Measurement Results

Table 8 Comments for Measure Function from MAV Example Program (Continued)

BASIC ‘MAV’ Example Program

Program Line

Number

360

370

380 390

400

410 430

440

Comments

Perform a serial poll to read the Status Byte from the Test Set. A serial poll is used because the *STB Common Command cannot be processed by the Test Set while a query is pending. Sending the *STB command will cause an ’HP-IB Error: -410 Query INTERRUPTED’ error.

Check bit 4, the Message Available bit (MAV), to see if it is set to ’1’. If it is, then the requested measurement result is ready.

Read the measurement result. Set the trigger mode to repetitive retriggering. Setting the trigger mode to

repetitive will be implementation dependent. Re-enable event initiated branching. If any event initiated branches were logged

while the Measure function was executing they will be executed when system priority permits.

Exit the Measure function and re turn the result value. Check to see if the measurement result time out value has been equaled or

exceeded. If it has the polling loop will be exited. The following lines of code handle the case where the request for a measurement

result has timed out because the polling loop has completed with no result available.

450

460

470

Set up a timeout for any I/O activity on the GPIB while the control program is trying to regain control of the Test Set. This will allow the function to gracefully stop program execution if the control program cannot regain control of the Test Set. This timeout should only occur if there is some type of hardware failure, either in the Test Set or the externa l controller, which prevents them from communicating via GPIB.

Send a Selected Device Clear (SDC) to the Test Set to put the GPIB subsystem into a known state. This allows the control program to regain programmatic control of the Test Set.

Chapter 2, Methods For Reading Measurement Results

BASIC ‘MAV’ Example Program

Table 8 Comments for Measure Function from MAV Example Program (Continued)

Program Line

Number

480

Exit the Measure function and re turn a result value of 9.E+99.

Comments

490 The following lines of code handle the case where the control program cannot

regain control of the Test Set. The actions taken in this section of the code will be implementation dependent. For the example case a message is displayed to the operator and the program is stopped.

500 Display a message to the operator that the control program cannot regain control

of the Test Set.

510 Stop execution of the control program.

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GPIB

Command Guidelines

1. GPIB was formerly called HP-IB for Hewlett-Packard instruments. Some labels on

the instrument may still reflect the former HP

name.

Chapter 3, GPIB Command Guidelines

Sequential and Overlapped Commands

IEEE 488.2 makes the distinction between sequential and overlapped commands. Sequential commands complete their task before execution of the next command can begin. Overlapped commands can run concurrently, that is, a command following an overlapped command may begin execution while the overlapped command is st ill in progress. All commands in the Test Set are seque ntial.

The processing architecture of the Test Set allows it to accept commands through the GPIB while it is exec uting c ommands alr eady pa rsed i nto it s comma nd buf fer. While this may appear to be overlapped, commands are always executed sequentially in the order received.

The process of executing a command can be divided into three steps:

1. Command is accepted from GPIB and checked for proper structure and parameters.

2. Commands is sent to instrument hardware.

3. Instrument hardware fully responds after some time, ∆t.

For example, in programming the Test Set’s RF Signal Generator it takes < 150 ms after receipt of the frequency setting command for the output signal to be within 100 Hz of the desired frequency. In the Test Set, commands are considered to have “completed their task” at the end of step 2. In manual operation all displayed measurement results take into account the instrument hardware’s response time. When programming measurements through GPIB the Triggering mode selected will determine whether the instrument’s response time is accounted for automati call y or if the cont rol pro gra m must accou nt for it. Refer

“Triggering Measurements” o n page 258 for a discussi on of the dif fe rent T rigg er

modes available in the Test Set and their affect on measurement results.

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Guidelines for Operation

The following topics discuss rules and guidelines for controlling the Test Set through GPIB.

Command Names

All command names of more than four characters have an alternate abbreviated form using only upper case letters and, in some cases, a single numeral. The commands are not ca se se nsiti ve. Uppe r and lower case chara cters can be use d for all commands.

For example, to set the destination of AF Generator 1 to Audio Out, any of the following command strings are valid:

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

AFGENERATOR1:DESTINATION ’AUDIO OUT’ or afgenerator1:destination ’audio out’ or afg1:dest ’audio out’ or AFG1:DEST ’AUDIO OUT’ or Afg1:Dest ’Audio oUT’

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Command Punctuation

NOTE: Programming Language Considerations. The punctuation rules for the Test Set’s

GPIB commands conform to the IEEE 488.2 standard. It is possible that some programming languages used on external controllers may not accept some of the punctuation requirements. It is therefor e n ecessary that the equivalent form of the correct punctuation, as defined by the language, be used for GPIB operation. Improper punctuation will results in HP-IB Error: -102 Syntax Error.

Using Quotes for String Entries

Quotation marks ’ and " a re used to select a n on-numeric field se tting . The value i s entered into the command line as a quoted alphanumeric string.

Quotes are used with all Underlined (toggling) and One-of-many (menu choice) fields. (See “Chan ging A Field’s Setting” in chapter 1 of the User’s Guide for field type descriptions.)

For example, to set the RF Generator’ s

Output Port field to Dupl (duplex), the

Dupl would be entered into the command string.

RFG:OUTP ’Dupl’ or RFG:OUTP "Dupl"

Using Spaces

When changing a field’s setting, a space must always precede the setting value in the command string, regardless of the field type (command<space>value).

RFG:FREQ<space>850MHZ RFG:ATT<space>’OFF’

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Using Colons to Separate Co mmands

The GPIB command syntax is structured using a control hierarchy that is analogous to manual operation.

The control hierarchy for making a manual instrument setting using the frontpanel contro ls is as follow s: first the screen is acces sed, then the desired field is selected, then the appropriate setting is made. GPIB commands use the same hierarchy. The colon (:) is used to sepa rate the different levels of th e command hierarchy.

For example, to set the AF Analyzer input gain to 40 dB, the following command syntax would be used:

DISP AFAN AFAN:INP:GAIN ’40 dB’

Using the Semicolon to Output Multiple Commands

Multiple commands can be output from one program line by separating the

commands with a semicolon (;). The semicolon tells t he Test Se t’s GPIB command parser to back up one level of hierarchy and accept the next command at the same level as the previous command.

For example, on one command line, it is possible to

1. access the AF ANALYZER screen,

2. set the AF Analyzer’s Input to AM Demod

3. set Filter 1 to 300 Hz HPF

4. set Filter 2 to 3kHz LPF

DISP AFAN;AFAN:INP ’AM DEMOD’;FILT1 ’300Hz HPF’;FILT2 ’3kHz LPF’

The semicolon after the “DISP AFAN” command tells the Test Set’s GPIB command parser that the next command is at the same level in the command hierarchy as the display command. Similarly, the semicolon after the INP 'AM DEMOD' command tells the command parser that the next comma nd (FILT1 '300Hz HPF') is at the same command level as the INP 'AM DEMOD' command.

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Using the Semicolon and Col on to Output Multiple Commands

A semicolon followed by a colon (;:) tells t he GPI B c ommand parser that the next command is at the top level of the command hierarchy. This allows commands from different instruments to be output on one command line. The following

example sets the RF Analyz er’s tune frequency to 850 MHz, and then sets the AF Analyzer’s input to FM Demod.

RFAN:FREQ 850MHZ;:AFAN:INP ’FM DEMOD’

Using Question Marks to Query Setting or Measurement Fields

The question mark (?) is used to query (read-back) an instrument setting or measurement value. To generate the query form of a command, pl ace th e quest ion mark immediately after the command. Queried infor mation must be read into the proper variable type within the program context before it can be displayed, printed, or used as a numeric value in the program.

Queried info rmation is re turned in the same format us ed to set the v alue: queried numeric fields return numeric data; quoted string fields return quoted string information.

For example, the following BASIC language program statements query the current setting of the

!Query the AFGen1 To field OUTPUT 714;"AFG1:DEST?" !Enter queried value into a string variable. ENTER 714;Afg1_to$

AFGen 1 To field:

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Specifying Units-of-Measure for Settings and Measurement Results

Numeric settings and measurement results in the Test Set can be displayed using

one or more units-of-measur e (V, mV, mV, Hz, kHz, MHz…). When operating the Test Set manually, the units-of-measure can be easily changed to display measurement results and field settings in the most convenient format. GPIB operation is similar to manual operation in that the units-of-measure used to display numeric data can be programmatically changed to the most convenient form.

NOTE: When querying measurements or settin gs through GPIB, the Test Set always returns numeric

There are three sets of units-of-measure used in the Test Set: Display Units, GPIB Units, and Attribute Units. Writing correct GPIB programs requires an understanding of how the Test Set deals with these different sets of units-ofmeasure.

Display Units (DUNits)

Display Units are the units-of-measure used by the Test Set to display numeric data (field settings and measurement results) on the front-panel CRT display. For

example, the RF Generator’s frequency can be displayed in Hz, kHz, MHz and GHz. Similarly, the measured TX Frequency can be displayed in Hz, kHz, MHz and GHz.

When evaluating an entered value for a numeric fiel d, the Test Set interprets the data it receives in ter ms of the Display Units c urrently set. For example, if the Display Units for the enter 500 into the field, an

RF Gen Freq field are set to GHz and the operator t ries to

Input value out of range error is generated

since the Test Set interpreted the value as 500 GHz which is outside the valid frequency range of the Test Set.

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Changing Display Units.

Use the DUNits command to change the units-ofmeasure used by the Test Set to display any field setting or measurement result. For example, to change the Display Units setting for the field from

MEAS:RFR:POW:DUN DBM

W to dBm, the following command would be used:

TX Power measurement

Display Units DUNits Command Example

GHz :MEAS:RFR:FREQ:ABS:DUN GHZ MHz :MEAS:RFR:FREQ:ABS:DUN MHZ kHz :MEAS:RFR:FREQ:ABS:DUN KHZ Hz :MEAS:RFR:FREQ:ABS:DUN HZ ppm :MEAS:RFR:FREQ:ERR:DUN PPM %D :MEAS:RFR:FREQ:ERR:DUN PCTDIFF V :MEAS:RFR:POW:DUN V mV :MEAS:RFR:POW:DUN MV mV :RFG:AMPL:DUN UV dBmV :RFG:AMPL:DUN DBUV W :MEAS:RFR:POW:DUN W mW :MEAS:RFR:POW:DUN MW dBm :MEAS:RFR:POW:DUN DBM db :MEAS:AFR:DISTN:DUN DB % :MEAS:AFR:DISTN:DUN PCT s :DEC:FGEN:GATE:DUN S ms :DEC:FGEN:GATE:DUN MS

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Reading Back Display Units Setting. Use the Display Units query command,

DUNits?, to read back the current Display Units setting. For example, the following BASIC language program statements query the current Display Units setting for the

!Query Display Units setting for TX Power measurement. OUTPUT 714;"MEAS:RFR:POW:DUNits?" !Enter the returned value into a string variable. ENTER 714;A$

TX Power measurement:

The returned units-of-measure will be whatever is shown on the Test Set’s frontpanel display for the TX Power measurement: dBm, V, mV, dBuV, or W. All returned characters are in upper case. For example, if dBuV is displayed, DBUV is returned.

Guidelines for Display Units

• When querying a field’s setting or measurement result through GPIB, the Test Set always returns numeric values in GPIB Units or Attribute Units, regardless of the field’s curre nt D i splay Units setting.

• The Display Units for a field’s setting or measurement result can be set to any valid unit-of-measure, regardless of the field’s GPIB Units or Attribute Units.

• The Display Units setting for a field’s setting is not affected when changing the field’s value through GPIB.

For example, if the AFGen1 Freq Display Units are set to kHz, and the command AFG1:FREQ 10 HZ is sent to change AFGen1’s frequency to 10 Hz, the Test Set displays 0.0100 kHz; not 10 Hz.

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

GPIB Units (UNITs)

GPIB Units are the units-of-measure used by the Test Set when sending numeric data (field settings and measurement results) through GPIB, and the default unitsof-measure for receiving numeric data (field settings and measurement results) through GPIB. Changing GPIB Units has no affect on the Display Units or Attribute Units settings.

Table 9 GPIB Units

Power Watts (W) or dBm (DBM) Amplitude Volts (V), or dBµV (DBUV) Frequency Hertz (Hz) Frequency Error Hertz (HZ) or parts per million (PPM) Time Seconds (S) Data Rate Bits per second (BPS) Current Amperes (A) Resistance Ohms (OHM) Relative Level decibels (DB) or percent (PCT) Marker Position Division (DIV) FM Modulation Hertz (HZ) AM Modulation Percent (PCT)

Table 9 lists the GPIB Units used in the Test Set.

Parameter Unit of Measure

Use the UNITs? command to determine the GPIB Units for a measurement result or field setting (refer to

“Reading-Back GPIB Units.” on page 76 for more

information).

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Changing GPIB Units. Use the UNITs command to change the GPIB Units

setting for selected measurement or instrument setup fields. Only the GPIB units for power, relative level, and frequency error can be changed.

Table 10 lists the

measurement and instrument setup fields which have changeable GPIB Units.

Table 10 GPIB Units That Can B e Changed

Function Available GP IB Units

TX Power measurement W or DBM Adjacent Channel Power

LRATio, URATio DB or PCT

LLEVel, ULEVel W or DBM SINAD measurement DB or PCT DISTN measurement DB or PCT SNR measurement DB or PCT RF Generator Amplitude W or DBM or V or DBUV Frequency Error HZ or PPM

For example, the following BASIC language program statements change the GPIB Units fo r the

OUTPUT 714;"MEAS:RFR:POW:UNIT DBM"

TX Power measurement from W to dBm:

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Reading-Back GPIB Units.

Use the UNITs? command to read back the current GPIB Units setti ng for a measurement or instrumen t setup field. For ex ample, the following BASIC language pr ogram statements read back the current GPIB Units setting for the

!Query the current GPIB Units setting for TX Power. OUTPUT 714;"MEAS:RFR:POW:UNIT?" !Enter the returned value into a string variable. ENTER 714;A$

Guidelines for GPIB Units

• When setting the value of a numeric field (such as AFGen1 Freq), any non–GPIB

Unit unit-of-measure must be specified in the command string, otherwise the current GPIB Unit is assumed by the Test Set.

For example, if the command RFG:FREQ 900 is sent through GPIB, the Test Set will interpret the data as 900 Hz, since HZ is the GPIB Unit for frequency. This would result in an Input value out of range error. Sending the command RFG:FREQ 900 MHZ would set the value to 900 MHz.

• When querying measurements or settings through GPIB, the Test Set always returns

numeric values in GPIB units, regardless of the current Display Unit setting. Numeric values are expressed in scientific notation.

For example, if the TX Frequency measurement is displayed as 150.000000 MHz on the Test Set, the value returned through GPIB is 1.5000000E+008 (1.5×10

Converting the returned value to a format other than scientific notation must be done programmatically.

TX Power measurement:

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Attribute Units (AUNits)

Attribute Units are the units-of-measure used by the Test Set when sending or receiving numeric data through GPIB for the MEASure commands: REFerence, METer (HEND, LEND, INT), HLIMit and LLIMit (refer to

Measurement Syntax” on page 195

for further details). These measurem ent

“Number

commands are analogous to the front-panel Data Function keys: REF SET, METER, HI LIMIT and LO LIMIT respectively. Attribute Units use the same set of units-of-measure as the GPIB Units (except Frequency Error), but are only used with the MEASure commands: REFerence, METer (HEND, LEND, INT), HLIMit and LL IMit.

Table 11 Attribute Units

Power Watts (W) or dBm (DBM) Amplitude Volts (V) Frequency Hertz (Hz) Time Seconds (S) Data Rate Bits per second (BPS) Current Amperes (A) Resistance Ohms (OHM) Relative Level decibels (DB) or percent (PCT) Marker Position Division (DIV) FM Modulation Hertz (HZ) AM Modulation Percent (PCT)

Table 11 lists the Attribute Units used in the Test Set.

Parameter Unit of Measure

Default Data Function Values. The majority of measurements made with the Test

Set can be made using the Data Functions: REF SET, METER, AVG, HI LIMIT and LO LIMIT. Measurements which can be made usin g the Data Funct i ons ha ve

a black bubble with the comment “See Number Measurement Syntax” in their syntax path. If one or more of the Data Functions are not available to that measurement, the Data Function(s) not available will be listed under the black bubble (see the syntax diagram,

“Measure” on page 165).

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

For each measurement that can be made using the Data Functions, there is a default set of values for each Data Function for that measureme nt.

For example, the Audio Frequency Analyzer Distortion measurement can be made using all of the Data Functions. This would include REF SET, METER, AVG, HI LIMIT and LO LIMIT. A complete listing of the Distortion

measurement’s Data Functions and their default values would appear as follows:

• The Attribute units are: PCT

• The number of Averages is: 10

• The Average state is: 0

• The Reference value is: 1

• The Reference Display units are: PCT

• The Reference state is: 0

• The High Limit is: 0

• The High Limit Display units are: PCT

• The High Limit state is: 0

• The Low Limit is: 0

• The Low Limit Display units are: PCT

• The Low Limit state is: 0

• The Meter state is: 0

• The Meter high end setting is: 10

• The Meter high end Display units are: PCT

• The Meter low end setting is: 0

• The Meter low end Display units are: PCT

• The Meter interval is: 10

The Data Fun ctions are set to their default va lues whenever

• the power is cycled on the Test Set

• the front-panel PRESET key is selected

• the *RST Common Command is received through GPIB

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Chapter 3, GPIB Command Guidelines

Changing Attribute Units. The AUNits command can be used to change the

Attribute Un its setting for selected me asurements. Only the Attribute Units for power and relative level measurements can be changed. measurements which have changeable Attribute Units.

Table 12 Measurements with Attribute Units That Can Be Changed

Function Available Attribute Units

TX Power measurement W or DBM Adjacent Channel Power

LRATio, URATio DB or PCT

LLEVel, ULEVel W or DBM SINAD measurement DB or PCT DISTN measurement DB or PCT SNR measurement DB or PCT

Guidelines for Operation

Table 12 lists the

Before chan ging the Attr ibute Units for a selected measurement, the Test Set verifies that all Data Function values can be properly converted from the current unit-of-measure to the new uni t-of-measure . The following Data Funct ion settings are checked:

• the Reference value

• the High Limit

• the Low Limit

• the Meter’s high end setting

• the Meter’s low end setting

• the Meter’s interval

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

If it is not possible to properly convert all the values to the new unit-of-measure, the Attribute Units are not changed and the following error is generated:

HP-IB Error: HP-IB Units cause invalid conversion of attr.

This error is most often encountered when one of the Data Function values listed above is set to zero. If this error is encountered, the programmer must change the Data Function settings to va lues that can be converted to t he new units-of -measure before sending the :AUNits command to the Test Set.

For example, the following BASIC language program statements

1. reset the Test Set

2. set the Data Function default zero values to non-zero values

3. set the Attribute Units to DB

4. then query the value of each Data Function

The units of me asure for the returned values will be DB.

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Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Display Units and GPIB Units are not affected when changing Attribute Units.

!Reset the Test Set OUTPUT 714;"*RST" !Set HIgh LIMIT value to 15 OUTPUT 714;"MEAS:AFR:DIST:HLIM:VAL 15" !Set LOw LIMIT value to 1 OUTPUT 714;"MEAS:AFR:DIST:LLIM:VAL 1" !Set the Meter Lo End value to 1 OUTPUT 714;"MEAS:AFR:DIST:MET:LEND 1" !Set Attribute Units for Distortion measurement to DB OUTPUT 714;"MEAS:AFR:DIST:AUN DB" !Query the REFerence SET value OUTPUT 714;"MEAS:AFR:DIST:REF:VAL?" !Read the REFerence SET value into variable Ref_set_val ENTER 714;Ref_set_val !Query the HIgh LIMIT value OUTPUT 714;"MEAS:AFR:DIST:HLIM:VAL?" !Read the HIgh LIMIT value into variable Hi_limit_val ENTER 714;Hi_limit_val !Query the LOw LIMIT value OUTPUT 714;"MEAS:AFR:DIST:LLIM:VAL?" !Read the LOw LIMIT value into variable Lo_limit_val ENTER 714;Lo_limit_val !Query the Meter Hi End value OUTPUT 714;"MEAS:AFR:DIST:MET:HEND?" !Read the Meter Hi End value into variable Met_hiend_val ENTER 714;Met_hiend_val !Query the Meter Lo End value OUTPUT 714;"MEAS:AFR:DIST:MET:LEND?" !Read the Meter Lo End value into variable Met_loend_val ENTER 714;Met_loend_val !Query the Meter interval OUTPUT 714;"MEAS:AFR:DIST:MET:INT?" !Read the Meter interval into! variable Met_int_val ENTER 714;Met_int_val

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Reading-back Attribute Units.

Use the AUNits? command to read back the Attribute Units setting for the selected measurement. For example, the following BASIC language program statements show how the AUNits? command can be used to read-back a Distortion REFerence SET level:

!Query the REFerence SET value for the Distortion measurement OUTPUT 714;"MEAS:AFR:DIST:REF:VAL?" !Read the REFerence SET value into variable Ref_set_val ENTER 714;Ref_set_val !Query the Attribute Units setting for the Distortion measurement OUTPUT 714;"MEAS:AFR:DIST:AUN?" !Read the Attribute Units setting into string variable Atribute_set$ ENTER 714;Atribute_set$ !Print out the variables in the form <VALUE><UNITS> PRINT Ref_set_val;Atribute_set$

If a reference of 25% is set, 25 PCT would be printed.

Guidelines for Attribute Units

• When setting the value of measurement functions REFerence, METer, HLIMit and LLIMit through GPIB, a non–Attribute Unit unit-of-measure must be specified in the command string, otherwise the current Attribute Unit is assu med by the Test Set.

For example, if the Test Set is in a RESET condition and the command MEAS:AFR:DIST:REF:VAL 10 is sent throug h GP IB, the Test Set will interpret the data as 10 %, since % is the RESET Attribute Unit for the Distor tion measurement. Sending the command, MEAS:AFR:DIST:REF:VAL 10 DBM, would set the REFerence SET value to 10 dB.

• When querying measurement functions REFerence, METer, HLIMit and LLIMit through GPIB, the Test Set always returns numeric values in Attribute Units, regardless of the current Display Units or GPIB Units settings. Numeric values are expressed in scientific notation.

For example, if the REF SET measurement function is displayed as 25% on the Test

Set, the value returned through GPIB is +2.50000 000E+001 (2.5×10

). Converting the returned value to a format other than scientific notation must be done programmatically.

• Before changing the Attribute Units for a selected measurement, the Test Set verifies that all Data Function values can be properly converted fro m the cu rren t unit-ofmeasure to the new unit-of-measure. If it is not possible to prop erly convert all the values to the new unit-of-measure, the Attribute Units are not changed and the following error is generated: HP-IB Error: HP-IB Units cause invalid

conversion of attr.

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Using the STATe Command

The STATe command corresponds to the front-panel ON/OFF key and is used to programmatically turn measurements, instrument functions, and data functions ON or OFF.

Turning measurements, instrument functions and data functions ON/OFF

Use 1 or ON to turn measurements, instrument functions, or data functions ON. Use 0 or OFF to turn measurements, instrument functions, or data functions OFF.

For example, the following BASIC language statements illustrate the use of the STATe command to turn several measurements, instrument functions, and data functions ON and OFF:

!Turn off FM source AFG1. * OUTPUT 714;"AFG1:FM:STAT OFF" !Turn off REFerence SET data function OUTPUT 714;"MEAS:AFR:DISTN:REF:STAT OFF" !Turn off TX Power measurement OUTPUT 714;"MEAS:RFR:POW:STAT 0" !Turn on REF SET measurement function for FM Deviation measurement OUTPUT 714;"MEAS:AFR:FM:REF:STAT ON"

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

*This assumes the AFGen1 To field is set to FM.

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

Reading back the measurement, instrument function, or data function state

Use the query form of the command, STATe?, to determine the current state of a measuremen t, instrument function or data function . If a measurement, instrument

function, or data function is queried, the returned value will be either a “1” (ON) or a “0” (OFF).

For example, the following BASIC language statements illustrate the use of the STATe? command to determine the current state of the TX Power measurement:

!Query the state of the TX Power measurement OUTPUT 714;"MEAS:RFR:POW:STAT?" ENTER 714;State_on_off IF State_on_off = 1 THEN DISP "TX Power Measurement is ON" IF State_on_off = 0 THEN DISP "TX Power Measurement is OFF

STATe Command Guidelines

• Measurements that are displayed as numbers, or as analog meters using the METER function, can be turned on and off.

• The data functions REFerence, METer, HLIMit, and LLIMit can be turned on and off.

• Any instrument functio n that gene rates a sign al can be turned on and of f. This includes the RF Generator, Tracking Generator, AF Generator 1, AF Generator 2, and the Signaling Encoder.

• The Oscilloscope’s trace cannot be turned off.

• The Spectrum Analyzer’s trace cannot be turned off.

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Sample GPIB Program

The following program was written on an HP® 9000 Series 300 controller using

Rocky Mountain BASIC (RMB). To run this program directly in the Test Set’s IBASIC Controller make the following modifications:

1. Use exclamation marks (!) to comment-out lines 440, 450, and 460 (these commands

2. Change line 70 to Bus = 8 (internal GPIB select code = 8).

10 ! This program generates an FM carrier, measures and displays the 20 !deviation, and draws the modulation waveform from the 30 !oscilloscope to the CRT display. For demonstration purpos es the 40 ! carrier is generated and analyzed through the uncalibrated input 50! path so that no external cables are required. 60 GCLEAR !Clear graphics display. 70 Bus=7 ! Interface select code of GPIB interface 80 Dut=100*Bus+14 ! Default Test Set GPIB address is 14 90 CLEAR Bus ! Good practice to clear the bus 100 CLEAR SCREEN ! Clear the CRT 110 OUTPUT Dut;"*RST" ! Preset the Test Set 120 OUTPUT Dut;"DISP DUPL" ! Display the DUPLEX TEST screen 130 OUTPUT Dut;"RFG:AMPL -14 DBM" ! Set RF Gen Amptd to -14 dBm 140 OUTPUT Dut;"AFAN:INP ’FM Demod’"

150 ! Set AF Analyzer’s input to FM Demod 160 OUTPUT Dut;"AFAN:DET 'Pk+-Max'" 170 ! Set AF Analyzer’s detector to Peak +/-Max 180 ! The following trigger guarantees the instrument will auto-tune 190 !and auto-range to the input signal before measuring. 200 OUTPUT Dut;"TRIG"! Trigger all active measurements 210 OUTPUT Dut;"MEAS:AFR:FM?" ! Request an FM deviation measurement 220 ENTER Dut;Dev ! Read measured value into variable Dev 230 PRINT USING "K,D.DDD,K";"Measured FM = ",Dev/1000," kHz peak." 240 DISP "'Continue' when ready..." ! Set up user prompt 245 ! Set up interrupt on softkey 1 250 ON KEY 1 LABEL "Continue",15 GOTO Proceed 260 LOOP! Loop until the key is pressed 270 END LOOP 280 Proceed: OFF KEY! Turn off interrupt from softkey 1 290 DISP "! Clear the user prompt 300 ! 310 !Measure and plot oscilloscope trace to see the waveform shape. 320 DIM Trace(0:416)! Oscilloscope has 417 trace points 330 OUTPUT Dut;"DISP OSC" Display the Oscilloscope screen 340 OUTPUT Dut;"TRIG"! Trigger all active measurements 350 OUTPUT Dut;"MEAS:OSC:TRAC?" 360 !Request the oscilloscope trace 370 ENTER Dut;Trace(*)

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

not supported in IBASIC).

Chapter 3, GPIB Command Guidelines

Guidelines for Operation

380 ! Read the oscilloscope trace into array Trace(*) 390 ! CRT is (X,Y)=(0,0) in lower left corner 400 !to (399,179) upper right. 410 ! (Each pixel is about 0.02 mm wide by 0.03 mm tall, not square.) 420 ! Scale vertically for 0 kHz dev center-screen and +4 kHz dev top 430 ! of screen. Leave the next three lines for external control, or 440 ! comment them out for IBASIC (Test Set stand-alone) control. 450 ! 460 PLOTTER IS CRT,"98627A" 470 !Your display may have a different specifier. 480 GRAPHICS ON!Enable graphics to plot the waveform. 490 WINDOW 0,399,0,179 500 ! 510 PEN 1 !Turn on drawing pen 520 MOVE 0,89.5+Trace(0)/4000*89.5 530 FOR I=1 TO 416 540 DRAW I/416*399,89.5+Trace(I)/4000*89.5 550 NEXT I 560 END

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GPIB Commands

Chapter 4, GPIB Commands

GPIB Syntax Diagrams

GPIB Command Syntax Diagram Listing

Instrument Command Syntax Diagrams

AF Analyzer (AFAN), page 93. AF Generator 1 (AFG1), page 96. AF Generator 2 (AFG2) - Pre-Modulation Filters, page 97. AF Generator 2 and Encoder (AFG2, ENC), page 98.

AFG2:AMPS, page 99. AFG2:CDCSs, page 103. AFG2:DPAGing, page 104. AFG2:DTMF, page 103. AFG2:EDACs, page 110. AFG2:FGENerator, page 106. AFG2:LTR, page 109. AFG2:MPT1327, page 111. AFG2:NAMPs, page 101. AFG2:NMT, page 107. AFG2:NTACs, page 101. AFG2:TACS, page 99.

AFG2:TSEQuential, page 106. Adjacent Channel Power (ACP), page 91. Call Process(CALLP), page 122. Decoder (DEC), page 159.

DEC:AMPS, page 161.

DEC:CDCSs, page 161.

DEC:DPAGing, page 161.

DEC:DTMF, page 161.

DEC:EDACs, page 160.

DEC:FGENerator, page 161.

DEC:LTR, page 162.

DEC:MPT1327, page 162.

DEC:NAMPs, page 160.

DEC:NTACs, page 160.

DEC:TACS, page 161.

DEC:TSEQuential, page 162. Oscilloscope (OSC), page 172. RF Analyzer (RF A), page 179. RF Generator (RFG), page 181. Radio Interface (RINT), page 182. Spectrum Analyzer (SAN), page 183.

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Instrument Command Number Setti ng Syntax Diagrams

Integer Number Setting Syntax, page 192. Real Number Setting Syntax, page 193. Multiple Real Number Setting Syntax, page 194.

Measurement Command Syntax Diagrams

Measure (MEAS), page 165. Tri gger (TRIG), page 191.

Measurement Command Number Setting Syntax Diagrams

Number Measurement Syntax, page 195. Multiple Number Measurement Syntax, page 197.

Instrument Function Syntax Diagrams

Chapter 4, GPIB Commands

GPIB Syntax Diagrams

Configure and I/O Configure (CONF), page 113. Display (DISP), page 163. Program (PROG), page 177. Save/Recall Registers (REG), page 178. Status (STAT), page 186. System (SYS), page 187. Tests (TEST), page 188.

GPIB Only Command Syntax Diagram

Special (SPEC), page 185.

Chapter 4, GPIB Commands

GPIB Syntax Diagrams

Diagram Conventions

Use the following diagram to see the conventions used in the syntax diagrams. Statement elements are con nect ed by lin es. Each line can be followed in only one

direction, as indicated by the arrow at the end of the line. Any combination of statement elements that can be generated by starting at the root element and following the line the proper direction is syntactically correct. An element is optional if there is a path around it. The drawings show the proper use of spaces.

Where spaces are r equi re d t hey are indicated by a hexagon wit h t he word “space” in it, otherwise no spaces are allowed between statement elements.

Root Element

AFGenerator2

Indicates the name of the display screen’s field that is controlled by this command element.

Directs the user to a specific Instrument Command, Measurement Command, or Number Setting Command syntax diagram. The Number Setting Commands are used to format numeric data and configure various instrument measurement parameters.

Notes indicate which, if any, Number Setting Commands are not supported by this particular path.

(Black oval at root level indicates continuation from previous page.)

:CDCSs

(Field Name)

:CODE

:RATE

space

See Real Number Setting Syntax*

(*Does not included the :STATe command)

‘ ‘

Returns quoted string

string

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Adjacent Channel Power (ACP)

:ACPower

:CBAN

(Channel BW)

See Real Number Setting Syntax*

*Does not include the :STA Te command

Adjacent Channel Power (ACP)

:COFFset

(Ch Offset)

:MEASurement

(ACP Meas)

:RBANdwidth

(Res BW)

:RMODulation

(Carrier Ref)

See Real Number Setting Syntax*

*Does not include the :STA Te command

space

’

Returns quoted string

’

Returns quoted string

’

Returns quoted string

Ratio Level

300 Hz

1 kHz

Unmod

Mod

’

Adjacent Channel Power (ACP)

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AF Analyzer

:AFANalyzer

:AIN

(Audio In Lo)

:CURRent

:ZERO

space

’

Returns quoted string

Gnd

Float

600 To Hi

AF Analyzer

’

:DEMPhasis

:DETector

:GAIN

(De-Emp Gain)

:PKLocation

(Pk Det To)

:SETTling

space

’

Returns quoted string

’

Returns quoted string

’

Returns quoted string

’

Returns quoted string

’

750 uS

Off

0 dB 10 dB 20 dB 30 dB

RMS

RMS*SQRT2

PK+ PK-

PK+-/2

PK+MAX PK+HOLD PK-HOLD PK+-/2 Hd

PK+-MX Hd

Filters

De-Emp

Fast

Slow

’

:AFAN continued

Returns quoted string

AF Analyzer

:AFANalyzer

:ELResistor

:FILTer1

See Real Number Setting Syntax*

*Does not include the :STATe command

space

’

Optional Filters

Returns quoted string

<20Hz HPF

50Hz HPF

300Hz HPF

’

:FILTer2

:GTIMe

:INPut

(AF Anl In)

:AFAN continued

See Real Number Setting Syntax*

*Does not include the :STATe command

:GAIN

(Input Gain)

space

’

Optional Filters

Returns quoted string

’

Returns quoted string

’

Returns quoted string

300Hz LPF

3kHz LPF 15kHz LPF >99kHz LP

FM Demod AM Demod

SSB Demod

Audio In Radio Int Ext Mod Mic Mod FM Mod AM Mod

Audio Out

0 dB 20 dB 40 dB

’

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:AFANalyzer

:NOTCh

:FREQuency

:GAIN

See Real Number Setting Syntax*

*Does not include the :STATe command

space

’

0 dB 10 dB 20 dB 30 dB 40 dB

Returns quoted string

AF Analyzer

’

:RANGing

:SMPoint

(Scope To)

:SPEaker

:MODE

(Speaker ALC)

:VOLume

space

’

Returns quoted string

’

Returns quoted string

’

Returns quoted string

’

Returns quoted string

Auto

Hold

De-Emp

Filters

Input

Notch

On Off

Pot Off

’

AF Generator 1

:AFGenerator1 :AFG1

:DESTination

(AFGen1 To)

:AM

See Real Number Setting Syntax

space

’

Returns quoted string

Audio Out

’

:FM

:OUTPut

:FREQuency

In setting AFGener ator 1, you must first sel ec t a destination (DESTination), then

See Real Number Setting Syntax

See Real Number Setting Syntax*

*Does not include the :STATe command

set the modulation depth (AM), or deviation (FM) or amplitude (OUTPut), then set the modulation rate or audio output frequency (FREQuency)

AM sets depth when DESTination set to AM. FM sets deviation when DESTination set to FM. OUTPut sets amplitude when DESTination set to Audio Out. FREQuency sets modulation rate when DESTination set to AM, FM. FREQuency sets audio output frequency when DESTination set to Audio Out.

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AF Generator 2 Pre-Modulation Filters

To improve performance, one of four pre-modulation filters is automatically selected for each Encoder Mode. The automatically selected filter can only be changed using GPIB commands; however, we recommend you do not ch ange thi s setting. In o rder to chang e the automatically select ed filter, the Filter Mode must be set to ON. Filter Mode ON allows independent selection of filters. The Filter Mode ON command must be executed first to override default settings. Filter Mode OFF is the power up default s tate. The foll owing er ror wil l occur if the user attempts to select an alternate filter w ithout first setting the Filter Mode to ON:

Entry not accepted. Auto entries take precedence. The syntax to change or

query the premodulation filter is shown below.

AFG2:FILTER:MODE ’ON|OFF’(select one) AFG2:FILTER:MODE?(query the current mode setting) AFG2:FILTER ’NONE|20kHz LPF|250Hz LPF|150Hz LPF’(select one) AFG2:FILTER?(query the current filter setting)

AF Generator 2 Pre-Modulation Filters

:AFGenerator2

:AFG2

:ENCoder

:FILTER

:MODE

space

’

Returns quoted string

’

Returns quoted string

NONE 20kHz LPF 250Hz LPF 150Hz LPF

OFF

’

AF Generator 2/Encoder

:AFGenerator2

:AFG2

:ENCoder

:AM :BURSt

*:INCRement command onl y

:DESTination

(AFGen2 To)

:FM

See Real Number Setting Syntax See IntegerNumber Setting Syntax*

See Real Number Setting Syntax

space

’

Returns quoted string

AM FM

Audio Out

’

:FREQuency

:MODE

:OUTPut

:PEMPhasis

:POLarity

:SEND

See Real Number Setting Syntax*

*Does not include the :STATe command

See Real Number Setting Syntax

:MODE

space

’

NAMP-NTACS

Returns quoted string

’

Returns quoted string

’

Returns quoted string

’

Func Gen

Tone Seq

DTMF

CDCSS

Digi Page

AMPS-TACS

NMT

MPT 1327

LTR

EDACS

Off

Norm

Invert

Single

Burst

Cont Step

’

:STOP

:AFG2 continued

S:\agilent\8920\8920b\PRGGUIDE\BOOK\SECTIONS\afg2_enc.sec

Returns quoted string

:AMPS or :TACS

:AFGenerator2 :ENCoder

:AMPS :TACS

:BUSY (Busy/Idle)

:CHANnel

:DATA

:DELay

(B/I Delay)

:AM :FM :LEVel

space

See IntegerNumber Setting Syntax*

*:INCRement command onl y

space

1 1

See Real Number Setting Syntax

See Real Number Setting Syntax See Real Number Setting Syntax

’

Returns quoted string

’

Returns quoted string

AF Generator 2/Encoder

Ilde

Busy WS Delay 1stBitDly

On Off

’

:RATE

:FILLer

:DATA 1

:DATA 2

:SEND :STOP

:AFG2:AMP Continued On Next Page

:AFG2 continued

See Real Number Setting Syntax*

*Does not include the :STATe command

space

’

Returns quoted string

1 AM, FM, and LEVel correspond to the setting of the AFGen2 To field.

string

’

AF Generator 2/Encoder

:AFGenerator2 :ENCoder

:AMPS :TACS

:FVCMessage

space

’

string

’

:MESSage

:SAT

:STANDard

:AFG2 continued

:DATA 1 :DATA 2

:AM :FM :LEVel

:FREQuency

See Real Number Setting Syntax

See Real Number Setting Syntax See Real Number Setting Syntax*

*Does not include the :STATe command

space

’

1 AM, FM, and LEVel correspond to the setting of the AFGen2 To field.

Returns quoted string

string

Returns quoted string

AMPS

TACS

JTACS

Returns quoted string

’

100

S:\agilent\8920\8920b\PRGGUIDE\BOOK\SECTIONS\afg2_enc.sec

Agilent 8920B Programming Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Using GPIB

Overview of the Test Set

Manual Control Mode

Internal Automatic Control Mode

External Automatic Control Mode

Writing programs for the Test Set

Getting Started

What is GPIB?

GPIB Information Provided in This Manual

General GPIB Programming Guidelines

Control Annunciators

Preparing the Test Set For GPIB Use

Using the GPIB with the Test Set’s built-in IBASIC Controller

Basic Programming Examples

Remote Operation

Remote Capabilities

Addressing

Factory Set Address

Extended Addressing

Multiple Addressing

Setting the Test Set’s Bus Address

Displaying the Bus Address

IEEE 488.1 Remote Interface Message Capabilities

Remote/Local Modes

Remote Mode

Local Mode

Remote or Local Mode

Local To Remote Transitions

Remote To Local Transitions

Local Lockout

Clear Lockout/Set Local

Methods For Reading Measurement Results

Background

HP® BASIC ‘ON TIMEOUT’ Example Program

Comments for Recommended Routine

HP® BASIC ‘MAV’ Example Program

Comments for Recommended Routine

Sequential and Overlapped Commands

Guidelines for Operation

Command Names

Command Punctuation

Specifying Units-of-Measure for Settings and Measurement Results

Using the STATe Command

Sample GPIB Program

GPIB Commands

GPIB Syntax Diagrams

GPIB Command Syntax Diagram Listing

Diagram Conventions

Adjacent Channel Power (ACP)

AF Analyzer

AF Generator 1

AF Generator 2 Pre-Modulation Filters

AF Generator 2/Encoder

:AMPS or :TACS