HP 8712ET, 8712ES, 8714ET, 8714ES User Manual Supplement

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Automating Measurements

HP 8712ET/ES and HP 8714ET/ES

RF Network Analyzers

User’s Guide Supplement

HP Part No. 08714-90014

Printed in USA

Print Date: October 1999

Supersedes: October 1998

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Notice

Softkey

The information contained in this document is subject to change without notice. Hewlett-Packard 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. Hewlett-Packard 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.

Key Conventions

This manual uses the following conventions:

FRONT PANEL KEY

analyzer (a “hardkey”).

: This indicates a “softkey”—a key whose label is determined by the instrument’s ﬁrmware, and is displayed on the right side of the instrument’s screen next to the eight unlabeled keys.

: This represents a key physically located on the

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Acknowledgments

Excel™ is a product of Microsoft Corp. Lotus® 1-2-3®, and Lotus WordPro are U.S. registered trademarks of

Lotus Development Corporation. Microsoft is a U.S. registered trademark of Microsoft Corporation. QuickBasic™ is a product of Microsoft Corp.

Portions of the software include source code from the Info–ZIP group. This code is freely available on the Internet by anonymous ftp asftp.uu.net:/pub/archiving/zip/unzip51/.tar.Z, and from CompuServe asunz51.zip in the IBMPRO forum, library 10, (data compression).

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Hewlett-Packard Sales & Service Ofﬁces

UNITED STATES Instrument Support Center

Hewlett-Packard Company (800) 403-0801

EUROPEAN FIELD OPERATIONS Headquarters

Hewlett-Packard S.A. 150, Route du Nant-d’Avril 1217 Meyrin 2/ Geneva Switzerland (41 22) 780.8111

Great Britain Hewlett-Packard Ltd. Eskdale Road, Winnersh Triangle Wokingham, Berkshire RG41 5DZ England (44 734) 696622

INTERCON FIELD OPERATIONS Headquarters

Hewlett-Packard Company 3495 Deer Creek Rd. Palo Alto, CA 94304-1316 USA (415) 857-5027

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Australia Hewlett-Packard Australia Ltd. 31-41 Joseph Street Blackburn, Victoria 3130 (61 3) 895-2895

Germany Hewlett-Packard GmbH Hewlett-Packard Strasse 61352 Bad Homburg v.d.H Germany (49 6172) 16-0

Canada Hewlett-Packard (Canada) Ltd. 17500 South Service Road Trans-Canada Highway Kirkland, Quebec H9J 2X8 Canada (514) 697-4232

Japan Hewlett-Packard Japan, Ltd. Measurement Assistance Center 9-1, Takakura-Cho, Hachioji-Shi Tokyo 192-8510, Japan TEL (81) -426-56-7832 FAX (81) -426-56-7840

China China Hewlett-Packard Co. 38 Bei San Huan X1 Road Shuang Yu Shu Hai Dian District Beijing, China (86 1) 256-6888

Singapore Hewlett-Packard Singapore (Pte.) Ltd. 150 Beach Road #29-00 Gateway West Singapore 0718 (65) 291-9088

Taiwan Hewlett-Packard Taiwan 8th Floor, H-P Building 337 Fu Hsing North Road Taipei, Taiwan (886 2) 712-0404

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HP 8712ET/ES and HP 8714ET/ES Network Analyzer Documentation Map

The CDROM provides the contents of all of the documents listed below.

The User’s Guide shows how to make measurements, explains commonly-used features, and tells you how to get the most performance from the analyzer.

The LAN Interface User’s Guide Supplement shows how to use a local area network (LAN) for programming and remote operation of the analyzer.

The Automating Measurements User’s Guide Supplement provides information on how to conﬁgure and control test systems for automation of test processes.

The Programmer’s Guide provides programming information including HP-IB and SCPI command references, as well as short programming examples.

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The Example Programs Guide provides a tutorial introduction using BASIC programming examples to demonstrate the remote operation of the analyzer

The Service Guide provides the information needed to adjust, troubleshoot, repair, and verify analyzer conformance to published speciﬁcations.

The HP Instrument BASIC User’s Handbook describes programming and interfacing techniques using HP Instrument BASIC, and includes a language reference.

The HP Instrument BASIC User’s Handbook Supplement shows how to use HP Instrument BASIC to program the analyzer.

The Option 100 Fault Location and Structural Return Loss Measurements User’s Guide Supplement provides theory and measurement examples for making fault location and SRL measurements. (Shipped only with Option 100 analyzers.)

The CATV Quick Start Guide provides abbreviated instructions for testing the quality of coaxial cables. (Shipped only with Option 100 analyzers.)

The Cellular Antenna Quick Start Guide provides abbreviated instructions for verifying the performance of cellular antenna systems. (Shipped only with Option 100 analyzers.)

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Contents

1. Introduction

Automating Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

2. Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations. . . . . . . . . . . . . . . . . . . . . . 2-2

Stand-Alone Network Analyzers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

External Computer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

Expandability and Large Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Throughput Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Selecting a Measurement Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Stand-Alone Operation using IBASIC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Computer-Controlled HP-IB Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Computer-Controlled LAN Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Using IBASIC and External Control Together. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Selecting a Programming Language. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

HP BASIC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

IBASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

HP VEE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

Microsoft® QuickBasic™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

C and C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12

VXI plug&play Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Example Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

3. Operator Interaction

Prompting the Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Using Graphics to Create On-Screen Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

User-Deﬁned BEGIN Key Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Loading a User BEGIN Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Modifying a User BEGIN Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Using a Switch with User BEGIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

Using a Barcode Reader for Data Entry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

Using an External Keyboard for Data Entry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

Using the Analyzer's Title Feature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Hot Keys on External Keyboard for Common Functions . . . . . . . . . . . . . . . . . . . . . . 3-16

User-Deﬁned TTL Input/Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Using a Foot or Hand Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19

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Contents

Limit-Test Pass/Fail TTL Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21

Analyzer Port Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-22

Output for External VGA-Compatible Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-24

4. Measurement Setup and Control with Fast Recall

Using Fast Recall with the Front Panel or a Keyboard . . . . . . . . . . . . . . . . . . . . . . . . .4-3

Using Fast Recall with a Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5

5. Automated Measurement Setup and Control

Setting the Instrument State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

Recalling Instrument States from Disk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

Using Learn Strings to Save and Recall Instrument States . . . . . . . . . . . . . . . . . . .5-6

SCPI Commands that Modify a Single Parameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7

Fast Iterative Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8

Responsive Communication using SRQs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10

Using Both of the Analyzer's Measurement Channels . . . . . . . . . . . . . . . . . . . . . . . .5-11

Using Single Sweep to Measure and View All Four S-Parameters. . . . . . . . . . . . . . .5-12

AUTOST ﬁles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-15

6. Controlling Peripherals

Using the Parallel Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3

Writing to the Parallel Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6

Reading from the Parallel Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-9

Hardcopy Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-10

Using the Serial Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-11

7. Displaying Measurement Results

Graticule On/Off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3

Limit Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

To turn limit lines on or off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

To turn the fail icon on or off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

To turn the pass/fail text on or off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4

To move the position of the pass/fail indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5

Customized X-axis Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6

To turn on user-deﬁned X-axis annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6

To specify your start and stop values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6

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Contents

To specify a custom sufﬁx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

To turn the X-axis annotation on or off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Customized Measurement-Channel Annotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

To turn on user-deﬁned measurement-channel annotation. . . . . . . . . . . . . . . . . . . . 7-8

To specify the string to be displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

To restore default measurement-channel annotation . . . . . . . . . . . . . . . . . . . . . . . . 7-8

To turn measurement-channel annotation on or off. . . . . . . . . . . . . . . . . . . . . . . . . . 7-9

Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10

Title and Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

8. Saving Measurement Results

Querying Measurement Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

Saving the Measurement to Disk — Save ASCII. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Saving the Measurement to Disk — Save Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

Querying Marker Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6

Saving Measurement Results to Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7

Using Hardcopy Features to Print or Plot Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

Faster Hardcopies using a PCL5 Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9

Customizing Page Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9

Custom Data Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12

Statistical Process Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

Transferring Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15

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Contents

Page 11

1 Introduction

1-1

Page 12

Introduction

Automating Measurements

An automated measurement system is one where a computer performs some of the tasks that you would normally have to do manually.

The information in this book will help you learn how to automate your measurement system. Several features of the instrument that are useful for automation are explained.

NOTE The information in this book assumes that you are familiar with the

information provided in the Programmer's Guide, the HP Instrument

BASIC User's Handbook, and the HP Instrument BASIC User’s Handbook Supplement that were supplied with your analyzer.

This book explains how to control your analyzer using internal IBASIC or with an external computer connected via HP-IB. The analyzer’s internal CPU running IBASIC programs acts as a complete system controller residing inside your analyzer. You have the additional capability of controlling the analyzer over a LAN. Refer to the LAN Interface User’s Guide Supplement (supplied with the analyzer) for information.

Some of the analyzer features that support automation are built-in and operate solely on the analyzer; limit testing is one example of a built-in automation feature. Other features can be executed by programs running internally under IBASIC or on an external computer.

NOTE Example programs can be found in the following four locations:

• Web site http://www.hp.com or http://www.agilent.com. Use the search function to ﬁnd Web pages related to 8712 example programs.

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (DOS format): HP part number 08714-10003

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (LIF format): HP part number 08714-10004

• Example Programs Guide, HP 8712ET/ES and HP 8714ET/ES: HP part number 08714-90016

1-2 Automating Measurements

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Introduction

Automating Measurements

Use of automation improves the productivity of a measurement system by increasing the system's throughput. Throughput is typically measured as the amount of units or components produced over a particular period of time. Throughput can be increased by minimizing the time for the following factors:

• device handling time

• operator interaction time

• measurement speed

• data transfer speed

• computation speed (when applicable) Be sure to consider all of these factors when choosing and setting up an

automated system. Automating your measurements can help ensure consistent quality on a

production line. An automated system can perform repetitive tasks quickly and consistently. Automation can be used to direct you through a sequence of tests, to set instrument parameters, and to send prompts with helpful directions or diagrams. Automation is also used to collect data, to monitor production line performance, and to archive and analyze data.

Using a consistent, documented production process, while monitoring product quality, are important attributes of modern production and quality standards such as ISO-9000. These attributes are best achieved with an automated system.

NOTE Hewlett-Packard offers professional consulting services to help increase

your manufacturing productivity. A complete test process analysis can be performed by HP system engineers, who will work with your factory management, engineering, and production groups to evaluate various automation solutions. F or more information contact the nearest HP sales ofﬁce. Refer to the front of this book for a table of sales and service ofﬁces.

Automating Measurements 1-3

Page 14

Introduction

Automating Measurements

1-4 Automating Measurements

Page 15

2 Conﬁguring Your Test System

2-1

Page 16

Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations

When conﬁguring your test system, there are many things to consider, such as:

• how many test stations do you need now?

• how many test stations will be needed in the future?

• how much space is available at each test station?

• what type of testing will be done?

• how will the measurements be controlled?

• how will the data be analyzed and archived?

• what level of throughput is required? After answering these questions, you should decide which of the

following conﬁgurations best meets your needs.

2-2 Automating Measurements

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Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations

Stand-Alone Network Analyzers

In the stand-alone conﬁguration, you can either take advantage of the operator-initiated automation features, or you can use the internal CPU and IBASIC programs to further automate your measurements.

Stand-Alone Analyzer under Operator Control

In this conﬁguration, the measurement is controlled directly by the operator, with very little automation. No computer or IBASIC control is used, however the fast-recall feature may be used to quickly change between different instrument states. This conﬁguration is well suited for simple pass/fail testing using the built-in limit-testing features. Conﬁgure your system as a stand-alone analyzer if you would like to

• simplify test-system conﬁguration

• maintain full control by operators

• minimize test-development time

Stand-Alone Analyzer under IBASIC Control

In this conﬁguration, the measurement is controlled by an IBASIC program running inside the analyzer. With IBASIC, the measurement setup and control can be highly automated, reducing the burden on the operator. Since the measurement is under programmatic control, data can be collected and analyzed in order to monitor your process and quality. IBASIC's keystroke recording lets you construct programs quickly, without needing to refer to the programming documentation. Using AUTOST ﬁles, the analyzer will load and run your program when power is turned on.

Since no external computer is required, there are fewer system components to purchase, maintain, connect, and synchronize.

Automating Measurements 2-3

Page 18

Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations

Conﬁgure your system as a stand-alone instrument with IBASIC if you would like to

• simplify test-system conﬁguration

• minimize the space required for a system

• simplify programming with keystroke recording

• use key macros

• automate measurement setup and control

• simplify measurements

• collect data

• run application programs on the analyzer

Figure 2-1 depicts a stand-alone network analyzer running IBASIC.

Figure 2-1 Stand-Alone Network Analyzer Running IBASIC

BEGIN

2-4 Automating Measurements

Page 19

Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations

External Computer Control

You can use an external computer to control your analyzer or test system by using the LAN or HP-IB interface on your analyzer. Additionally, you can use an external computer in conjunction with the analyzer’s internal CPU running IBASIC for optimum throughput. (F or more information on using the LAN interface, refer to The LAN Interface User’s Guide Supplement.)

External Computer Alone

In this conﬁguration, the measurement is controlled by a computer external to the analyzer, using the LAN or the HP-IB interface. The measurement setup and control can be highly automated and designed for optimum throughput. Data can be automatically collected and analyzed in order to monitor quality and processes. You can connect one or more analyzers to each computer. Since the computer can be connected to other computers via a Local Area Network (LAN), measurement statistics can be easily tracked and archived using computer applications.

Conﬁgure your system as an analyzer controlled by an external computer if you would like to

• centralize automation and application programs

• develop a more sophisticated data collection system

• add networking capability

Figure 2-2 Network Analyzer Controlled by a Computer

Automating Measurements 2-5

Page 20

Conﬁguring Your Test System

Measurement System Conﬁgurations and Considerations

External Computer in Conjunction with IBASIC

In this conﬁguration, the measurement is controlled by an IBASIC program running inside the analyzer. IBASIC can provide high-speed measurement control and data collection, and save the results in program memory or on a disk. The external computer then communicates with IBASIC, and collects the measurement results at some deﬁned interval. This conﬁguration can result in higher throughput, especially if the measurement setup and control is complex. Conﬁgure your system as an analyzer with IBASIC and an external computer if you would like to

• centralize automation and application programs

• develop a more sophisticated data collection system

• add networking capability

• add local-automation capability

Figure 2-3 Network Analyzer Running IBASIC, Controlled by a Computer

2-6 Automating Measurements

Page 21

Conﬁguring Your Test System

HP-IB

Expandability and Large Systems

You can connect up to 10 analyzers to a single computer without compromising maximum HP-IB bus speed. The IEEE-488 standard states that the bus can achieve a data rate of 500 KBytes per second for buses up to 20 meters in length, with up to 10 devices (one device per 2 meters of cable).

IEEE-488 provides for 31 unique addresses (0 through 30), however it restricts the number of devices on the bus to 15. Due to this restriction, you may need to add more computers as you add more analyzers. Set each analyzer's address via the menu.

With your analyzer’s LAN feature, you can overcome the physical limitations of HP-IB cabling and create large systems with hundreds of analyzers. 10-BaseT LAN provides a theoretical bandwidth of close to 1 MByte/second, although in practice, throughput will be slower. See The LAN Interface User’s Guide Supplement for more information.

SYSTEM OPTIONS

Automating Measurements 2-7

Page 22

Conﬁguring Your Test System

Throughput Considerations

When considering the throughput of the system conﬁguration, contributing factors are

• device handling time

• operator interaction time

• measurement speed

• data transfer speed

• computation speed (when applicable) For more information, refer to Improving Throughput in Network

Analyzer Applications, HP application note number AN 1287-5 (or literature number 5966-3317E).

2-8 Automating Measurements

Page 23

Conﬁguring Your Test System

Selecting a Measurement Controller

There are three standard conﬁgurations that you can use to control the analyzer:

• stand-alone operation using IBASIC

• computer-controlled HP-IB operation

• computer-controlled LAN operation

Stand-Alone Operation using IBASIC

IBASIC, in effect, puts a controller inside your analyzer and eliminates the need for an external computer. IBASIC controls the analyzer by sending SCPI commands to address 800 (OUTPUT 800;”Command”), or by using high-speed built-in subprograms. Since IBASIC shares CPU time with the analyzer, it may cause some degradation in measurement throughput if your program performs intensive computations. However, for most applications, it provides excellent performance and convenience. Refer to the HP Instrument BASIC User's Handbook and HP Instrument BASIC User’s Handbook Supplement for more information.

Computer-Controlled HP-IB Operation

An external computer can be used to control the analyzer. It can be a personal computer (PC) or a dedicated HP BASIC controller. The external computer sends standard SCPI commands to address 716 (default) (OUTPUT 716;”Command”) to control the analyzer . Refer to the Programmer's Guide for more information.

You can use one computer to control several analyzers (see “Expandability and Large Systems” earlier in this chapter). However , if a large number of SCPI commands are required per measurement, throughput may be degraded. Typical limits are 3 to 10 analyzers per computer.

Automating Measurements 2-9

Page 24

Conﬁguring Your Test System

Selecting a Measurement Controller

Computer-Controlled LAN Operation

An external computer can send SCPI commands via the LAN using a telnet connection. Refer to The LAN Interface User’s Guide Supplement for more information.

You can use one computer to control several analyzers. Performance will typically be limited by the computer's speed, which in turn will limit the number of analyzers per computer.

Using IBASIC and External Control Together

The analyzer can be controlled by commands from an external computer, internal IBASIC, or from both at the same time, as long as certain precautions are observed. Things to consider:

1. If both the analyzer and the computer send SCPI commands at the same time, the analyzer may not ﬁnish the IBASIC command before executing the computer's command, or vice-versa. The programmer must ensure that SCPI commands executed by IBASIC do not overlap with SCPI commands sent from an external computer, otherwise the system may lock up. Synchronization between the analyzer and the external computer must be ensured. See “Synchronizing IBASIC with an External Controller” in HP Instrument BASIC User’s Handbook Supplement for additional information.

2. Both IBASIC (SelectCode 8) and the external computer (LAN or SelectCode 7) share the same HP-IB status model (the same analyzer status bits go to each). Be careful sending commands which affect status reporting, such as *CLS, STAT:PRES, *RST, etc.

2-10 Automating Measurements

Page 25

Conﬁguring Your Test System

Selecting a Programming Language

HP BASIC

HP BASIC has long been a favorite programming language for instrument control. It features an extensive list of keywords, and powerful OUTPUT and ENTER formatting, making it easy to perform common tasks. This generally results in very high programming productivity. HP BASIC runs on HP series 700 workstations and series 300 instrument controllers.

IBASIC

IBASIC is a version of BASIC that runs inside of the network analyzer. IBASIC is a sub-set of HP's BASIC . It has roughly the same keywords as

HP BASIC 4.0. With very little effort, you can design your program so that it will run either inside the analyzer or on a computer with no modiﬁcation.

The IBASIC program runs concurrently with normal instrument measurement processing. Since IBASIC has direct access to the analyzer's measurement arrays, it can read them and write to them very quickly, eliminating the need to use SCPI commands. Using IBASIC's keystroke recording, you can write a large portion of your instrument control program by pressing the keys on the analyzer's front panel. IBASIC can be used in a stand-alone instrument, or in conjunction with an external computer.

For more information on IBASIC, refer to the HP Instrument BASIC

User's Handbook and HP Instrument BASIC User’s Handbook Supplement that were shipped with your analyzer.

Automating Measurements 2-11

Page 26

Conﬁguring Your Test System

Selecting a Programming Language

HP VEE

HP VEE is a powerful application which lets you graphically create programs to control your instrument. VEE automatically handles the programming details so you can focus on higher level tasks. It also contains statistical functions which you can use to monitor your production process.

VEE runs on PCs as well as HP-UX and Sun Workstations. VEE can be used in conjunction with a VEE instrument driver. The VEE

instrument driver presents a picture of the instrument's front panel on the computer display. Using the mouse, you can click on the front panel keys to control the instrument, similar to IBASIC keystroke recording.

For information on VEE, including literature and preview disks, please call the nearest HP instrument support center, or sales or service ofﬁce. Refer to the front of this book for a table of sales and service ofﬁces.

Microsoft® QuickBasic™

QuickBasic has been a popular programming language since it runs on PCs. It does not offer a rich keyword set as does HP BASIC, and is not optimized for instrument control. To control the analyzer via HP-IB, an HP-IB card and driver library must be installed in the computer. The driver library will provide subroutines such as IOOUTPUT and IOENTER which let you control your analyzer.

C and C++

If you are using C or C++, you will need a driver library to use your HP-IB card. HP offers a library called Standard Instrument Control Library (SICL). SICL is available for PCs running Microsoft Windows® and using HP's HP-IB card. SICL is also available on HP series 700 UNIX workstations.

For LAN communication with your analyzer, C or C++ is often used. Multi-threaded programs can be created to allow easy and precise control of many analyzers operating asynchronously. This approach maximizes speed and throughput.

2-12 Automating Measurements

Page 27

Conﬁguring Your Test System

Selecting a Programming Language

VXI plug&play Driver

Your analyzer is VXI plug&play compliant. VXI plug&play drivers provide a high level control interface for the analyzer, thereby reducing the level of instrument-speciﬁc knowledge required to program the analyzer. The driver for the HP 8712ET/ES and HP 8714 ET/ES functions in Win95, Win98, and WinNT (3.51 or higher) and was designed for the following programming platforms:

• Microsoft Visual C++ version 4.0 or higher

• Microsoft Visual BASIC version 5.0 or higher

• Borland C++ version 4.5 or higher

• HP VEE version 3.2 or higher

• National Instruments Lab Window/CVI version 4.0.1 or higher

• National Instrument LabVIEW version 5.00 or higher The free VXI plug&play driver for your analyzer should be available

soon on the Web at:

http://www.tmo.hp.com/tmo/software/English/comptest_VXI_drivers.html

http://www.hp.com/go/ena

Example Programs

The Programmer's Guide contains detailed information on controlling the analyzer via HP-IB. The Example Programs Guide includes several example programs written in HP BASIC and in IBASIC.

The HP Instrument BASIC User's Handbook and HP Instrument BASIC User’s Handbook Supplement contain detailed information on how to control the analyzer using IBASIC.

The LAN Interface User’s Guide Supplement contains detailed information on controlling the analyzer via LAN, including example programs.

Automating Measurements 2-13

Page 28

Conﬁguring Your Test System

Selecting a Programming Language

2-14 Automating Measurements

Page 29

3 Operator Interaction

3-1

Page 30

Operator Interaction

Many tests are performed by technicians, operators, or testers who interact with the measurement system. When designing the automation system, it is important that the system allow operators to perform the measurement tasks quickly and consistently. The system must also be easy to learn and easy to use, providing the user with instructions and feedback.

The analyzer provides many features to satisfy these requirements. The features include

• user-deﬁned pop-up messages to prompt the operator

• on-screen graphics to create custom diagrams

• user-deﬁned measurement channel and frequency annotation

• ability to deﬁne the key menu with frequently-used custom softkeys

• IBASIC display window; conﬁgurable as full or split

• IBASIC DISP line and INPUT line

• data entry using a barcode reader

• data entry using an external keyboard

• hot keys on external keyboard for common functions

• operator control of measurements using a foot or hand switch

• beeper with adjustable volume and pitch

• limit test pass/fail TTL output

• user-deﬁned TTL input/output

• output for external VGA-compatible color monitor

The following sections explain how to use these features, and show several examples.

BEGIN

3-2 Automating Measurements

Page 31

Figure 3-1 shows an example test system setup which utilizes the

extensive connectivity capabilities of the analyzer. All of the interface ports shown are standard equipment on your analyzer.

Figure 3-1 Example Test System Setup

Operator Interaction

Automating Measurements 3-3

Page 32

Operator Interaction

Prompting the Operator

You can display a customized message in the center of the analyzer's display by using the following SCPI command:

DISPlay:ANNotation:MESSage

For example,

OUTPUT @Rfna;"DISP:ANN:MESS 'Connect device, then press button'"

You can specify how long you want the message to remain on the screen by using one of the following timeout words: SHORt, MEDium, LONG,

NONE. For example,

OUTPUT @Rfna;"DISP:ANN:MESS 'Test passed.'",MEDIUM

To clear the message immediately, use the following command:

DISPlay:ANNotation:MESSage:CLEar

The message string can contain a maximum of 25 lines with up to 47 characters per line. However , it cannot be more than 254 characters in length, including carriage returns and line feeds.

If you are using IBASIC, you can use the B ASIC keywordDISP to display a small one-line message near the bottom of the screen. For example,

DISP "Connect device to REFLECTION port"

3-4 Automating Measurements

Page 33

Operator Interaction

Using Graphics to Create On-Screen Diagrams

Diagrams showing how to connect devices or perform measurements can be a powerful tool. You can draw customized diagrams on the analyzer's display using the following SCPI commands:

DISPlay:WINDow[1|2|10]:GRAPhics:

These commands let you draw lines, rectangles, circ les , and text onto the screen. The number speciﬁed in the WINDow part of the command selects where the graphics are to be drawn:

WINDow1 draws the graphics to the measurement channel 1

window.

WINDow2 draws the graphics to the measurement channel 2

window. WINDow10 draws the graphics to the IBASIC display window. Using split display, you can display the measurement in one half of the

screen while displaying a connection diagram in the other half.

command

For more details on SCPI graphics commands, refer to “Using Graphics” in the Programmer's Guide.

If you are using IBASIC, you can use the B ASIC graphics keywords such as MOVE and DRAW to draw diagrams in the IBASIC window.

MOVE X1,Y1 DRAW X2,Y2

Since IBASIC keywords always draw to the IBASIC window, you cannot use them to draw in the same window as your measurement. To draw in the measurement window, your IBASIC program must use the standard SCPI commands.

DISP:WIND1:GRAPHICS:

and

DISP:WIND2:GRAPHICS:

For more details on IBASIC graphics, refer to “Graphics and Display Techniques” in the HP Instrument BASIC User’s Handbook Supplement.

Automating Measurements 3-5

command

Page 34

Operator Interaction

User BEGIN

User-Deﬁned BEGIN Key Menu

The feature adds the following capabilities:

• Create softkeys to allow one-key-press operation of functions that usually take several key presses.

• Reassign softkeys to implement your most-used functions/features.

• Create softkeys to implement new features created with IBASIC—for example, a gain-compression measurement.

• Create softkeys to implement application support.

This feature is designed to provide the fastest possible sweep speeds while taking advantage of the ﬂexibility provided by IBASIC. This is the simplest way for recalling instrument states or conﬁguring most-used softkey functions under a single softkey menu. The eighth softkey in the

BEGIN

softkey to enable/disable or . You cannot redeﬁne the eighth softkey.

menu provides access to the menus below. Toggle the eighth

BEGIN

Ampliﬁer Filter Broadband Passive Mixer Cable (Option 100 only)

User BEGIN on OFF −−−−>

Once you have selected a menu, the same menu will be displayed for subsequent key presses of the hardkey.

3-6 Automating Measurements

BEGIN

User label 1 User label 2 User label 3 User label 4 User label 5 User label 6 User label 7 User BEGIN ON off

Page 35

Operator Interaction

System Conﬁg

User TTL Conﬁg

Softkey Auto-Step

User BEGIN

User-Deﬁned BEGIN Key Menu

By selecting

SYSTEM OPTIONS

, you can automatically step

through the user-deﬁned menu keys by use of a switch

BEGIN

connected to the USER TTL IN/OUT rear panel connector. See “Using a

Switch with User BEGIN” on page 3-11 for more information.

Selecting the softkey will run a macro function deﬁned by a sequence of IBASIC commands deﬁned within an IBASIC program. IBASIC programs to be used for must have the following structure:

10 !The following label must be present. DO NOT REMOVE 20 User_begin: ! 30 ... 40 ! Define softkey labels 50 OUTPUT @871X;"DISP:MENU2:KEY1 'Test Setup 1';*WAI" 60 OUTPUT @871X;"DISP:MENU2:KEY2 'Test Setup 2';*WAI" 70 OUTPUT @871X;"DISP:MENU2:KEY3 'Save Results';*WAI" 80 OUTPUT @871X;"DISP:MENU2:KEY4 'Print Results 4';*WAI" 100 User_pause: PAUSE 110 GOTO User_pause 120 !The following key labels must be present. DO NOT REMOVE 140 User_key1: !Insert code for softkey 1 here 150 GOTO User_pause 160 User_key2: !Insert code for softkey 2 here 170 GOTO User_pause

200 User_key7: !Insert code for softkey 7 here 210 GOTO User_pause

...

Automating Measurements 3-7

Page 36

Operator Interaction

User BEGIN

Mkr --> Max

User-Deﬁned BEGIN Key Menu

The labels required are:

User_begin User_pause User_key1 User_key2 User_key3 User_key4 User_key5 User_key6 User_key7

NOTE Y our program must contain all of these labels, even if you

are not using all of the softkeys. A default program is created automatically when there

is no IBASIC program installed. In the default program, the third softkey is deﬁned to be the function, the fourth softkey prompts the user for a title, and also enables the clock. The default program is listed next. You may edit this program to change the functions you need. Once you have edited the program, be sure to save the program to memory for later recall.

1 ! The following line is required. DO NOT REMOVE! 2 User_begin: ASSIGN @Hp8714 TO 800 ![User Begin] Program 3! 4 ! To Modify: 5 ! Use [IBASIC][EDIT] or [IBASIC][Key Record] 6! 7! 8 ! Declare storage for variables. 9 DIM Name$[60],Str1$[60],Str2$[60],Str3$[60] 10 ! 11 ! Clear the softkey labels 12 OUTPUT @Hp8714;"DISP:MENU2:KEY8 '';*WAI" 13 ! 14 ! Re-define softkey labels here. 15 OUTPUT @Hp8714;"DISP:MENU2:KEY1 '*';*WAI" 16 OUTPUT @Hp8714;"DISP:MENU2:KEY2 '*';*WAI" 17 OUTPUT @Hp8714;"DISP:MENU2:KEY3 'Mkr -> Max';*WAI" 18 OUTPUT @Hp8714;"DISP:MENU2:KEY4 'Title and Clock';*WAI" 19 OUTPUT @Hp8714;"DISP:MENU2:KEY5 '*';*WAI" 20 OUTPUT @Hp8714;"DISP:MENU2:KEY6 '*';*WAI" 21 OUTPUT @Hp8714;"DISP:MENU2:KEY7 '*';*WAI" 22 ! 23 !The following 2 lines are required. DO NOT REMOVE!

3-8 Automating Measurements

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Operator Interaction

User BEGIN

User-Deﬁned BEGIN Key Menu

24 User_pause: PAUSE 25 GOTO User_pause 26 ! 27 User_key1: ! Define softkey 1 here. 28 GOSUB Message ! Remove this line. 29 GOTO User_pause 30 ! 31 User_key2: ! Define softkey 2 here. 32 GOSUB Message ! Remove this line 33 GOTO User_pause 34 ! 35 User_key3: ! Example Marker Function 36 OUTPUT @Hp8714;"CALC1:MARK1 ON" 37 OUTPUT @Hp8714;"CALC1:MARK:FUNC MAX" 38 GOTO User_pause 39 ! 40 User_key4: ! Example Title Entry 41 INPUT "Enter Title Line 1. Press [Enter] when done.",Name$ 42 OUTPUT @Hp8714;"DISP:ANN:TITL1:DATA '""'" 43 OUTPUT @Hp8714;"DISP:ANN:TITL ON" 44 GOTO User_pause 45 ! 46 User_key5: ! Define softkey 5 here. 47 GOSUB Message ! Remove this line. 48 GOTO User_pause 49 ! 50 User_key6: ! Define softkey 6 here. 51 GOSUB Message ! Remove this line. 52 GOTO User_pause 53 ! 54 User_key7: ! Define softkey 7 here. 55 GOSUB Message ! Remove this line. 56 GOTO User_pause 57 ! 58 Message: ! 59 Str1$="This key is programmable." 60 Str2$="To modify, select" 61 Str3$="[System Options], [IBASIC], [Edit]." 62 OUTPUT @Hp8714;"DISP:ANN:MESS '""', MEDIUM" 63 RETURN 64 ! 65 END

NOTE For more programs, see the Example Programs Disk and

the Example Programs Guide.

Automating Measurements 3-9

Page 38

Operator Interaction

User BEGIN

Autost

User BEGIN

IBASIC

Edit

Prior Menu

Key Record ON

IBASIC

Key Record OFF

User-Deﬁned BEGIN Key Menu

Loading a User BEGIN Program

A program can be automatically loaded at power up if the program is named “AUTOST”. An “AUTOST” program is loaded at power up from the internal non-volatile memory or from a 3.5 inch ﬂoppy disk inserted into the analyzer's disk drive. (To manually load and run an “AUTOST” ﬁle, press .) A program does not have to be an “AUTOST” program; it can also be loaded as any other IBASIC program. (See the HP Instrument BASIC User’s Handbook Supplement for more information.)

When the key is pressed, the program will remain idle until it is needed. The program remains idle until a softkey is pressed and code related to that softkey is executed. After the code is executed, the program returns to idle. Use of does not restrict access to any normally available front panel feature, nor does this key affect sweep update rates.

BEGIN

Modifying a User BEGIN Program

You can modify the User BEGIN program with the built-in editor, an ASCII ﬁle editor on a computer, or with keystroke recording. For example, to modify the default program to recall a setup:

1. Select . Move the edit cursor to line:

15 OUTPUT @Hp8712;"DISP:MENU2:KEY1 '*';*WAI"

2. Use an external keyboard to replace ‘*’ with ‘Setup 1’.

3. Move the edit cursor to line 28. Delete the line.

4. Use keystroke recording to create a setup function if you like, or you can now insert code you have written.

To use keystroke recording to modify the program:

5. Exit the editor by selecting .

6. Enable keystroke recording with .

7. Now perform the keystrokes required for Setup 1.

8. When the setup is completed, select

3-10 Automating Measurements

SYSTEM OPTIONS

Page 39

Operator Interaction

User BEGIN ON

User-Deﬁned BEGIN Key Menu

9. To verify your change, select .

10.Select the ﬁrst softkey which should be labeled “Setup 1”. This should

return you to your correct setup.

11.You may save this program as an AUTOST ﬁle or other ﬁle for later

recall.

Refer to the HP Instrument BASIC User’s Handbook Supplement.

PRESET BEGIN

Using a Switch with User BEGIN

When user-deﬁned is used in conjunction with a switch connected to the USER TTL IN/OUT rear-panel connector, you can cycle through up to seven softkeys in sequence by activating the switch.

1. Connect a switch to the USER TTL IN/OUT rear panel connector as

shown in Figure 3-2.

Figure 3-2 Connecting a Switch to the USER TTL IN/OUT Connector

BEGIN

Automating Measurements 3-11

Page 40

Operator Interaction

System Conﬁg

User TTL Conﬁg

Softkey Auto-Step

User-Deﬁned BEGIN Key Menu

2. Make sure the analyzer is conﬁgured to use the USER TTL IN/OUT connector for softkey sequencing: press

3. Press the switch several times while observing the analyzer.

4. Notice that with each press of the switch, the softkey labels are highlighted (boxed) in succession, and that after the last available key has been used, the sequence starts again at the top of the softkey menu.

SYSTEM OPTIONS

3-12 Automating Measurements

Page 41

Operator Interaction

Using a Barcode Reader for Data Entry

Devices under test (DUTs) are often labeled with a serial number and part number. If the DUT is labeled with this information in barcode format, a barcode reader can be used to enter the DUT information into the analyzer or into the computer controlling the analyzer. Doing so provides a simple and safe link between the DUT and the measurement data. Information such as the operator's name or test station number can also be entered, to allow correlation of the devices tested with the test station.

Connect a barcode reader, such as the HP KeyWand HBKW-1220, to the analyzer's DIN KEYBOARD connector (on the rear panel). Once connected, the barcode reader will send scanned barcode characters to the analyzer just as if they were typed on a keyboard. The barcode characters will be followed by a carriage return. The barcode wand and the external keyboard can be connected simultaneously.

See “Using the Analyzer's Title Feature” on page 3-15 for more information on using the title feature with a barcode reader.

In addition to Hewlett-Packard's barcode wand, other vendors offer products such as cordless barcode readers, laser scanner readers, barcode label printers, barcode fonts for Windows®, and barcode labeling software. For more information about Hewlett-Packard barcode products—including listings for distributors worldwide—please visit our Web page at http://www.hp.com/HP-COMP/barcode.

Automating Measurements 3-13

Page 42

Operator Interaction

Using an External Keyboard for Data Entry

An IBM PC-AT compatible keyboard can be connected to your analyzer's DIN KEYBOARD connector and used to quickly and conveniently enter ﬁle names for instrument state save/recall, or text for title lines.

NOTE If your keyboard has a standard (large) DIN connector, you will need to

use a DIN to mini-DIN adapter to connect the keyboard to the analyzer. These adapters are available as HP part number 1252-4141. Contact the nearest HP sales or service ofﬁce for more information.

See “Using the Analyzer's Title Feature” on page 3-15 for more information.

3-14 Automating Measurements

Page 43

Operator Interaction

More Display

Title and Clock

Title Line 1

Using the Analyzer's Title Feature

The analyzer has two 30-character title lines which can be entered using the barcode reader. From the front panel, press

keyboard, press F9. Then use the barcode reader to scan in the information from the DUT or use a keyboard to type in the information. Once stored in the title line, the information will be included on hardcopy dumps. The title lines can also be set or queried using the following SCPI command:

DISPlay:ANNotation:TITLe[1|2]:DATA

For example:

OUTPUT @Rfna;"DISP:ANN:TITL1:DATA 'BPF-177, SN US95170001'"

and

OUTPUT @Rfna;"DISPlay:ANNotation:TITLe1:DATA?" ENTER @Rfna;Title1$

Use the command

"DISPlay:ANNotation:TITLe[1|2] ON|OFF"

to display or hide the title. If you are using IBASIC, you can use the INPUT statement to read in barcode or keyboard characters. For example:

30 INPUT "Scan in the Barcode now",Dut$ 40 OUTPUT 800;"DISP:ANN:TITL1:DATA '";Dut$;"'" 50 OUTPUT 800;"DISP:ANN:TITL1 ON" 60 END

DISPLAY

, or on an external

Automating Measurements 3-15

Page 44

Operator Interaction

Hot Keys on External Keyboard for Common Functions

You can use a keyboard's keys instead of the analyzer's keys to control the analyzer. provides the same information that can be found on a template that is supplied with each analyzer (HP part number 08712-80028). Function keys F9, F10, and F11 are “hot keys” which perform common operations such as entering measurement titles and saving measurement results to disk.

3-16 Automating Measurements

Page 45

Hot Keys on External Keyboard for Common Functions

Table 3-1 Keyboard Template Deﬁnition

Operator Interaction

Keyboard

Key Name

F1 Softkey 1 Shift-F1

F2 Softkey 2 Shift-F2

F3 Softkey 3 Shift-F3

F4 Softkey 4 Shift-F4

F5 Softkey 5 Shift-F5

F6 Softkey 6 Shift-F6

F7 Softkey 7 Shift-F7

F8 Softkey 8 Shift-F8

F9 Title Keys Line 1 or RCL

F10

F11

F12

Analyzer Function

Title Keys Line 2 or Edit

Title Keys Clock or Window

Re-save File or Run

Keyboard

Key Name

Shift-F9

Shift-F10

Shift-F11

Shift-F12

Analyzer Function

MEAS 1 MEAS 2 FREQ POWER SWEEP MENU SCALE MARKER DISPLAY FORMAT CAL AVG

Esc IBASIC Command Line On/Off Ctrl-F2

Print Screen Help Ctrl-F3

Ctrl-Print Screen Hardcopy Keyboard Template Ctrl-F4

Shift-Print Screen Hard Copy Graph and Softkeys Ctrl-F5

Ctrl-F1

1. When the IBASIC command line is enabled

SAVE RECALL

Automating Measurements 3-17

HARDCOPY SYSTEM OPTIONS PRESET BEGIN

Page 46

Operator Interaction

System Conﬁg

User TTL Conﬁg

Default

User-Deﬁned TTL Input/Output

The USER TTL port can be used as a general-purpose input or output. Like the LIMIT TEST IN/OUT line, the USER TTL IN/OUT line is an open-collector drive. When used as an input, the state of the USER TTL IN/OUT line can be read with either the SCPI command

"DIAG:PORT:READ? 15,1"

or with the IBASIC command

I = READIO(15,1)

When used as an output, the state of the USER TTL IN/OUT line can be set with either the SCPI command

"DIAG:PORT:WRITE 15,1,value"

or with the IBASIC command

WRITEIO 15,1;value

The USER TTL IN/OUT port can also be used in conjunction with an external switch for softkey auto-stepping, or as a “sweep out” port. Be sure that USER TTL IN/OUT port is conﬁgured properly for general-purpose I/O by pressing

SYST:COMM:TTL:USER:FEED DEFAULT

SYSTEM OPTIONS

. Or use the following SCPI command:

CAUTION Be sure to observe static precautions when using this port.

3-18 Automating Measurements

Page 47

Operator Interaction

Using a Foot or Hand Switch

You can connect a foot switch, button box, or custom keyboard which has a few function keys that are custom-labeled, and use this in conjunction with IBASIC to allow consistent, error-free step-by-step measurement control. The operator presses one key, then the next, in order.

NOTE A switch can also be used with the analyzer’s fast-recall feature. See

“Using Fast Recall with a Switch” on page 4-5.

The foot-switch simply connects two wires together, grounding the center pin of the analyzer's USER TTL IN/OUT rear panel connector. (See

Figure 3-2.) The status of the USER TTL IN/OUT can be read using the

SCPI commands:

30 OUTPUT 716;"DIAG:PORT:READ? 15,1" 40 ENTER 716;X

or the IBASIC command:

30 X=READIO(15,1)

When the foot-switch is open, the variable “X” will be set to 1. When it is closed, the variable “X” will be set to 0. Switch debounce is generally not a problem, due to the relatively slow polling rate of the program.

Refer to “Analyzer Port Numbers” on page 3-22 for tables describing the various analyzer ports that you can access using SCPI or IBASIC commands.

Following is an example program which shows how to displa y a message and read the foot switch to control your measurements. This program is named “TTL_IO” on your Example Programs Disk.

For an example which uses the IBASIC READIO command, refer to the program “USER_BIT” on your Example Programs Disk.

100 ! Filename: TTL_IO 110 ! 120 ! This program reads the USER TTL IO 130 ! port, and counts how many times a 140 ! switch connected to the port is pressed. 150 ! 160 DIM Msg$[200] 170 INTEGER X 180 ! 190 IF POS(SYSTEM$("SYSTEM ID"),"HP 871") THEN 200 ASSIGN @Hp8711 TO 800

Automating Measurements 3-19

Page 48

Operator Interaction

Using a Foot or Hand Switch

210 ELSE 220 ASSIGN @Hp8711 TO 716 230 ABORT 7 240 CLEAR 716 250 END IF 260 ! 270 Pass_count=0 280 Start: ! 290 LOOP 300 ! Display message 310 Msg$="'DUTs passed: "&VAL$(Pass_count)&CHR$(10) 320 Msg$=Msg$&"Press button to measure next DUT.'" 330 OUTPUT @Hp8711;"DISP:ANN:MESS ";Msg$ 340 ! 350 ! Wait for button to be pressed 360 REPEAT 370 OUTPUT @Hp8711;"DIAG:PORT:READ? 15,1" 380 ENTER @Hp8711;X 390 UNTILX=0 400 DISP "Button is now pressed." 410 OUTPUT @Hp8711;"DISP:ANN:MESS:CLEAR" 420 ! 430 ! Wait for button to be released 440 REPEAT 450 OUTPUT @Hp8711;"DIAG:PORT:READ? 15,1" 460 ENTER @Hp8711;X 470 UNTILX=1 480 DISP "Button is now released." 490 ! 500 OUTPUT @Hp8711;"DISP:ANN:MESS 'Measuring...'" 510 ! Add code here to take sweep 520 ! and measure DUT. 530 WAIT 1 540 Pass_count=Pass_count+1 550 END LOOP 560 END

3-20 Automating Measurements

Page 49

Operator Interaction

Limit-Test Pass/Fail TTL Input/Output

When limit testing is turned on, the LIMIT TEST IN/OUT rear-panel BNC connector indicates the status of the limit test. If the limit test passes, this TTL output goes high. If the limit test fails, this TTL output goes low. This signal can be used, for example, as an input to a materials handler.

CAUTION Since the TTL output has limited current drive capability, it should be

buffered when controlling high current devices such as mechanical relays. Otherwise, damage to the instrument may result.

The limit-test TTL can also be used as a general-purpose input, since the analyzer drive to this line is open collector. When used as an input, limit testing should be turned off so the instrument will allow the limit test line to ﬂoat high. The line can then be connected to an external switch which should only pull the signal to ground or let it ﬂoat (an external circuit should not drive this line). A push button or foot switch can be attached to the line to pull the signal to ground.

The state of the signal can be monitored by the automated system to determine when the operator is ready for some action. The state of the limit TTL line can be read with either the SCPI commands

20 INTEGER X 30 OUTPUT 716;"DIAG:PORT:READ? 15,2" 40 ENTER 716;X

or using the IBASIC command

30 X=READIO(15,2)

Finally, the LIMIT TEST TTL IN/OUT line can be used as a general-purpose output line. With limit testing turned off, the state of the line can be set to logic high or low with either the SCPI command

"DIAG:PORT:WRITE "

or with the IBASIC command

"WRITEIO ,value".

The following is an example of reading the LIMIT TEST TTL IN/OUT line when used as an input:

30 Limit = READIO(15,2) 40 ! The "Limit" variable will be set to 0 if the signal is low 50 ! and 1 if the signal is high.

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Operator Interaction

Analyzer Port Numbers

Table 3-2 Writeable Ports

Port

Number

15 0 Outputs 8-bit data to the Cent_D0 thru D7 lines of the Centronics port.

15 1 Sets/clears the user bit according to the least signiﬁcant bit of A. A least

15 2 Sets/clears the limit pass/fail bit according to the least signiﬁcant bit of A.

15 3 Outputs 8-bit data to the Cent_D0 thru D7 lines of the Centronics port.

9 0 Outputs a byte to the serial port. The byte is output serially according to

Cent_D0 is the least signiﬁcant bit, Cent_D7 is the most signiﬁcant bit. Checks Centronics status lines for:

Out of Paper Printer Not on Line BUSY ACKNOWLEDGE

signiﬁcant bit equal to 1 sets the user bit high. A least signiﬁcant bit of 0 clears the user bit.

A least signiﬁcant bit equal to 1 sets the pass/fail bit high. A least signiﬁcant bit of 0 clears the pass/fail bit.

Cent_D0 is the least signiﬁcant bit, Cent_D7 is the most signiﬁcant bit. Sets the Printer_select signal high (de-select). Does not check Centronics status lines.

the conﬁguration for the serial port.

NOTE When using the WRITEIO(15,0) or WRITEIO(15,3) command, the

Printer_Select Line is set high. However, when the instrument is doing hardcopy, the Printer_Select Line is set low. The Printer_Select line may or may not be used by individual printers. Check with your printer manual.

3-22 Automating Measurements

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Table 3-3 Readable Ports

Operator Interaction

Analyzer Port Numbers

Port

Number

9 0 Reads the serial port. 15 0 Reads the 8-bit data port Cent_D0 thru D7. 15 1 Reads the user bit. 15 2 Reads the limit test pass/fail bit. 15 10 Reads the 8-bit status port.

D0 — Cent_acknowledge D1 — Cent_busy D2 — Cent_out_of_paper D3 — Cent_on_line D4 — Cent_printer_err

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Operator Interaction

Output for External VGA-Compatible Monitor

You can connect a VGA-compatible external monitor to the VIDEO OUT COLOR VGA connector for a large-screen color view of your measurement if you wish. See “Using an External VGA Monitor” in Chapter 4 of your analyzer’s User’s Guide for information on using an external monitor with your system.

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4 Measurement Setup and

Control with Fast Recall

4-1

Page 54

Measurement Setup and Control with Fast Recall

The production and testing of RF components often involves several steps, with each step requiring a unique set of instrument settings. Likewise, the different test conﬁgurations at each step may require associated calibrations. Manually entering these sets of parameters (or “states”) or calibrating at each step in the manufacturing process is slow, prone to operator error, and costly. The fast-recall feature allows you to recall one of seven instrument states with just a single key press, or to cycle through up to seven different instrument states with a switch.

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Measurement Setup and Control with Fast Recall

Fast Recall on OFF

Select Disk

Non-Vol RAM Disk

Prior Menu

Fast Recall on OFF

Rename File

Using Fast Recall with the Front Panel or a Keyboard

NOTE The following explanation assumes that you are familiar with the

information presented in “Saving and Recalling Measurement Results” in Chapter 4 of your analyzer’s User’s Guide.

1. Press .

2. If the measurement display area changes to a listing of ﬁles on the currently selected disk, fast recall is off.

If the measurement display area remains unchanged, fast recall is on. To follow along with this explanation, turn fast recall off by pressing

3. If necessary, select the internal non-volatile RAM disk by pressing

4. If you have previously saved any ﬁles to this disk, they will now be listed on the display.

5. The fast recall feature utilizes only the ﬁrst seven ﬁles listed that contain instrument state, calibration, or measurement data.

6. If you have not previously saved any ﬁles to this disk, you may want to save a few instrument states now, to follow along.

7. Press so that “ON” is capitalized. Note that the measurement display now reappears on the screen and that there are ﬁle names next to the ﬁrst seven softkeys. (If any of the softkeys are blank, it's because you had less than seven ﬁles saved on the disk.)

The ﬁles are placed on the softkeys in the order in which they appear in the disk's directory table.

SAVE RECALL

so that “OFF” is capitalized.

NOTE You may want to use the feature to give your ﬁles more

meaningful names. See “Other File Utilities” in Chapter 4 of your analyzer’s User’s Guide for information on renaming ﬁles.

8. To “fast recall” an instrument state, press the softkey next to the ﬁle name that contains the instrument state.

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Measurement Setup and Control with Fast Recall

Using Fast Recall with the Front Panel or a Keyboard

9. The fast-recall mode will remain on (even when the analyzer is

PRESET

10.With the fast-recall feature turned on, you will always be only one or two key presses away from recalling an instrument state.

11.With an external keyboard connected to the rear panel DIN connector, keys F1 through F7 are equivalent to pressing softkeys 1 through 7 on the analyzer. See “Using a Keyboard” in Chapter 4 of your analyzer’s User’s Guide for information on connecting and using an external keyboard.

NOTE For test systems that include a multiport test set:

See the example program titled “MPSVRCL.” This IBASIC/RMB program requires an HP 8712ET/ES or HP 8714ET/ES analyzer connected to a multiport test set. The program saves three instrument states, each measuring various ports in ALT sweep mode. Fast recall is enabled so that subsequent recalls require a single keypress.

Example programs can be found in the following four locations:

• Web site http://www.hp.com or http://www.agilent.com. Use the

search function to ﬁnd Web pages related to 8712 example programs.

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (DOS

format): HP part number 08714-10003

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (LIF

format): HP part number 08714-10004

• Example Programs Guide, HP 8712ET/ES and HP 8714ET/ES: HP

part number 08714-90016

) until manually turned off.

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Measurement Setup and Control with Fast Recall

System Conﬁg

User TTL Conﬁg

Softkey Auto Step

Fast Recall

Using Fast Recall with a Switch

When fast recall is used in conjunction with a switch connected to the USER TTL IN/OUT rear panel connector, you can cycle through up to seven instrument states in sequence by activating the switch.

1. Connect a switch to the USER TTL IN/OUT rear panel connector as shown in Figure 4-1.

Figure 4-1 Connect a Switch to the USER TTL IN/OUT Connector

2. Make sure the analyzer is conﬁgured to use the USER TTL IN/OUT connector for softkey sequencing: press

3. With toggled to ON, press the switch several times while observing the analyzer.

4. Notice that with each press of the switch, the ﬁles are highlighted (boxed) in succession, and that after the last available ﬁle has been used, the sequence starts again at the top of the softkey menu.

Automating Measurements 4-5

SYSTEM OPTIONS

Page 58

Measurement Setup and Control with Fast Recall

Using Fast Recall with a Switch

4-6 Automating Measurements

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5 Automated Measurement Setup

and Control

5-1

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Automated Measurement Setup and Control

The production of RF components often involves several steps, with each step requiring a unique set of instrument settings. Likewise, the different test conﬁgurations at each step may require associated calibrations. Requiring the operator to manually enter these sets of parameters (or “states”) or to calibrate at each step in the manufacturing process is slow, prone to operator error, and costly.

An automated measurement system can be used to achieve fast and consistent transitions between measurement setups. In an automated system, the instrument parameters are set under program control. The control program can be an IBASIC program running inside the analyzer, or a program in another language running on an external computer. The control program sends SCPI and IEEE-488 commands to the analyzer's HP-IB or LAN interface. The HP-IB commands rapidly change the instrument settings or calibration.

Figure 5-1 Measurement Control

5-2 Automating Measurements

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Automated Measurement Setup and Control

The HP-IB or LAN interfaces can also be used to trigger sweeps, read measurement values, or signal events within the analyzer. Most operations that can be done from the front panel can also be done over the HP-IB or LAN interface. See the Programmer's Guide and the LAN Interface User’s Guide Supplement for details.

This chapter describes methods for changing instrument settings rapidly under program control. It then brieﬂy discusses how to synchronize the modiﬁcation of instrument settings with the collection of data and how to use service requests (SRQs) to signal instrument states. Finally, it describes how to utilize both measurement channels and a feature to automatically start an IBASIC control program.

For information on techniques that can improve your sweep speed, refer to “Optimizing Measurements” in your analyzer’s User’s Guide.

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Automated Measurement Setup and Control

Setting the Instrument State

A DUT will often undergo several different tests while at a single test station. The analyzer's parameters (such as sweep frequencies, output power, markers, and limits) must be set to the desired values before each test is performed. In an automated test system, the controlling computer modiﬁes the instrument settings for the operator. The analyzer offers several techniques for quickly changing the instrument's measurement parameters:

• Recall of instrument states from disk

• The learn string HP-IB command (*LRN)

• SCPI commands that change speciﬁc parameters

Recalling Instrument States from Disk

The analyzer has two internal memory (RAM) disks: “Non-Vol RAM Disk” and “Volatile RAM Disk.” A “RAM Disk” is a block of memory inside the analyzer which you can access in the same way that you access ﬁles on a ﬂoppy disk. In addition, the analyzer has a built-in 3.5 inch ﬂoppy-disk drive accessible on the front panel.

The “Non-Vol RAM Disk” is non-volatile, meaning that its contents are preserved while the analyzer is turned off. The contents of the “Volatile RAM Disk” are erased when the analyzer is turned off. The volatile RAM disk can be conﬁgured to be much larger than the non-volatile RAM disk, allowing it to hold many more instrument states.

The instrument settings and calibrations associated with several tests can be saved to instrument state ﬁles on any of the analyzer’s three disks described above. The instrument states can later be recalled during a test sequence. The advantage of using RAM disks rather than the

3.5 inch ﬂoppy disk is that recalling a state from RAM disks takes several seconds less than recalling a state from the ﬂoppy disk.

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Automated Measurement Setup and Control

Setting the Instrument State

For example, suppose the instrument settings are entered for the third test of a sequence of tests. The instrument settings can be saved in a ﬁle with the name “TEST3.STA” on the non-volatile RAM disk. When the third test must be performed, the control program can recall the instrument state from the non-volatile RAM disk with the following SCPI command:

MMEM:LOAD:STATe 1,'MEM:TEST3.STA'

Recalling a state from RAM disk typically takes about 4 seconds, but the time is dependent on settings such as number of points.

One strategy for managing a large set of recall states is to initially store them on a ﬂoppy disk. The ﬁles can then be copied from the ﬂoppy disk to the volatile RAM disk at the start of each day. Since recall time from the RAM disk is faster than recall from the ﬂoppy disk drive, throughput can be increased. For example , to copy the ﬁle 'TEST3.ST A' from the 3.5 inch disk to the non-volatile RAM disk, use the following SCPI command:

MMEM:COPY 'INT:TEST3.STA', 'MEM:'

For more details, see the Programmer's Guide. When controlling the analyzer with a computer, you may want to copy an

instrument state ﬁle from your computer to one of the analyzer's built-in RAM disks or the 3.5 inch disk. Later, the instrument can be instructed to recall the state from its internal disk. The ﬁle can be sent from the computer to the analyzer's disk using the SCPI MMEMory:TRANsfer commands. For more details, see the Programmer's Guide.

For manually controlled test systems, the instrument state ﬁles for each measurement can be stored onto disk by the test-system designer. During the test sequence, the operator can press the

SAVE RECALL

key and recall the instrument state for a particular measurement.

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Automated Measurement Setup and Control

Deﬁne Save

Setting the Instrument State

Using Learn Strings to Save and Recall Instrument States

The IEEE 488 *LRN (“learn”) command can also be used to set or query a complete set of instrument parameters. This can be used as a programming convenience, eliminating the need for using disk ﬁles when saving and recalling instrument states.

To obtain the learn string containing the instrument state, use the command *LRN? as follows:

10 DIM State1$[4000] 20 OUTPUT @Rfna;"*LRN?" 30 ENTER @Rfna USING "-K";State1$

... 160 ! Put the learn string back 170 OUTPUT @Rfna;State1$

Since *LRN?, by IEEE deﬁnition, only contains the actual instrument state, exclusive of data traces and calibration arrays, the network analyzer provides the command

SYST:SET:LRNLong?

This command saves the data traces and calibration arrays if they are enabled using or by using the MMEM:STOR:STATE SCPI commands. Using the *LRN command to set the instrument settings takes about the same amount of time as recalling a ﬁle from disk using MMEM:LOAD:STATe.

SAVE RECALL

For more details on learn strings, refer to the Example Programs Guide.

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Automated Measurement Setup and Control

SCPI Commands that Modify a Single Parameter

TIP If several measurement setups are similar — differing only by a few

instrument parameters — the fastest way to switch between the states is for the control program to send the SCPI commands that modify only those parameters.

For example, if center frequency and source power are the only parameters that change in consecutive measurement setups, send the SCPI commands SENS1:FREQ:CENT and SOUR1:POW to change these parameters, leaving all other instrument settings unchanged. This will be faster than either recalling an instrument state or sending a learn string.

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Automated Measurement Setup and Control

Fast Iterative Control

You may want to quickly and iteratively change the analyzer's parameters and monitor their effect on your device under test. This section describes how to quickly change a parameter, take a sweep, and query a marker.

For example, when measuring an ampliﬁer, you may wish to quickly choose the optimal input power to the ampliﬁer which will result in a maximum output of +10 dBm. To do so, you can ﬁrst set the analyzer's source power level, then measure the ampliﬁer's output, and then change the analyzer's source power in the direction that will cause the measured signal to approach the desired value. This process can be repeated until the measured ampliﬁer output is within some speciﬁed range of the target value.

When data at only a single frequency is needed, you can achieve the fastest possible sweep by selecting a CW frequency and setting the number of points to the minimum value of 3. A SCPI marker command can be used to read the trace value.

Using this approach, you can typically achieve 3 to 5 sweeps per second. Following is a listing of an example program named “FAST_CW” that can be found on your Example Programs Disk.

100 DIM Freq_str$[20] 110 DIM Msg$[100] 120 ! 130 IF POS(SYSTEM$("SYSTEM ID"),"HP 871") THEN 140 ASSIGN @Hp8711 TO 800 150 ELSE 160 ASSIGN @Hp8711 TO 716 170 ABORT 7 180 CLEAR 716 190 END IF 200 ! 210 ! PRESET, to ensure known state. 220 OUTPUT @Hp8711;"SYST:PRES;*WAI" 230 CLS 240 ! 250 ! Set up the analyzer to measure 3 data points. 260 OUTPUT @Hp8711;"SENS1:SWE:POIN 3;*WAI" 270 ! 280 ! Select CW display and sweep 290 OUTPUT @Hp8711;"DISP:ANN:FREQ1:MODE CW" 300 OUTPUT @Hp8711;"SENS1:FREQ:SPAN 0 Hz;*WAI" 310 ! 320 ! Take a single sweep, leaving the analyzer 330 ! in trigger hold mode.

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Automated Measurement Setup and Control

Fast Iterative Control

340 OUTPUT @Hp8711;"ABOR;:INIT1:CONT OFF;*WAI" 350 ! 360 ! Turn on Marker 1 370 OUTPUT @Hp8711;"CALC:MARK1 ON" 380 ! 390 Count=0 400 T0=TIMEDATE 410 ! Step from 175 MHz 463 MHz by 6 MHz 420 FOR Freq=175 TO 463 STEP 6 430 ! Take a sweep 440 Freq_str$=VAL$(Freq)&" MHz" 450 OUTPUT @Hp8711;"SENS1:FREQ:CENT ";Freq_str$ 460 OUTPUT @Hp8711;"INIT1;*WAI" 470 ! 480 ! Set marker to frequency 490 OUTPUT @Hp8711;"CALC:MARK:X ";Freq_str$ 500 ! 510 ! Query the marker value 520 OUTPUT @Hp8711;"CALC:MARK:Y?" 530 ENTER @Hp8711;Response 540 ! 550 ! Display the first three numbers in the array. 560 Msg$="'"&Freq_str$&": "&VAL$(Response)&"'" 570 OUTPUT @Hp8711;"DISP:ANN:MESS ";Msg$ 580 PRINT Msg$ 590 Count=Count+1 600 NEXT Freq 610 T1=TIMEDATE 620 PRINT "Sweeps per second: ";Count/(T1-T0) 630 DISP "Sweeps per second: ";Count/(T1-T0) 640 END

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Automated Measurement Setup and Control

Responsive Communication using SRQs

Service requests (SRQs) are a method by which you can instruct the analyzer to tell your computer program when a condition changes or when an event of interest occurs. This communication is done via HP-IB signals.

Analyzer SRQ events include:

• Limit test fails

• A front panel key or external keyboard key is pressed

• Hardcopy in progress or complete

• Sweep in progress or complete

• Power has been cycled The analyzer can be set to cause an SRQ on any combination of the above

events. Using SRQs allows your program to be interrupt driven, reducing the latency and inefﬁciency of polling. For more details, refer to “Using Status Registers” in the Programmer's Guide.

NOTE For test systems that include a multiport test set:

See the example program titled “MPCALSRQ.” This IBASIC/RMB program requires an HP 8712ET/ES or HP 8714ET/ES analyzer connected to a multiport test set. The program conﬁgures the analyzer’s status reporting so that an SRQ is issued whenever a SelfCal is initiated.

Example programs can be found in the following four locations:

• Web site http://www.hp.com or http://www.agilent.com. Use the search function to ﬁnd Web pages related to 8712 example programs.

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (DOS format): HP part number 08714-10003

• Example Programs Disk, HP 8712ET/ES and HP 8714ET/ES (LIF format): HP part number 08714-10004

• Example Programs Guide, HP 8712ET/ES and HP 8714ET/ES: HP part number 08714-90016

5-10 Automating Measurements

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Automated Measurement Setup and Control

Using Both of the Analyzer's Measurement Channels

The analyzer is capable of making different measurements on each of its two measurement channels. For example, you can set measurement channel 1 to measure transmission over one set of sweep frequencies, while measurement channel 2 is set to measure reﬂection over another set of sweep frequencies. Thus, two measurements can be made by the operator at the same time. Also, the controller can switch between measurement channel 1 and measurement channel 2, while turning the inactive channel off, to quickly change the test setup between two test states.

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Automated Measurement Setup and Control

Trigger

Single

Using Single Sweep to Measure and View All Four S-Parameters

You can save sweep time when measuring S-parameters on an HP 8712ES or HP 8714ES by using the single sweep feature. As long as a full two-port calibration has been performed, you can measure all four S-parameters with a single sweep cycle, and then individually view each S-parameter by then pressing the desired S-parameter softkey under the

MEAS 1 MEAS 2

From the front panel, set up your measurement parameters, perform (or recall) a valid full two-port calibration, and then connect the DUT. Press

sweep to capture all four S-parameters, and then goes into “hold sweep” mode. Press or , and then any of the S-parameter measurement keys to view the desired parameter.

The SCPI command to perform a single sweep and then hold is

ABOR;:INIT[1|2]:CONT OFF;:INIT[1|2]; *WAI

or menu.

. The analyzer takes a forward and reverse

MEAS 1 MEAS 2

For an automated example, see the example program listed below. This program is also available titled “FOURPARM” on your Example Programs Disk.

1000 !Filename: FOURPARM 1010 ! 1020 ! Demonstrates that all four S-parameters can be computed by 1030 ! the instrument after a single sweep. 1040 ! 1050 ! Outline: 1060 ! 1. Select Default 2-Port Cal 1070 ! 2. Select S11 on MEAS 1. S21 on MEAS 2. 1080 ! These are Port 1 Reflection and forward transmission. 1090 ! Take a sweep. 1100 ! 3. Do Data->Mem on MEAS 1 and on MEAS 2. 1110 ! 4. Without taking another sweep, select 1120 ! S22 on MEAS 1 and S12 on MEAS 2. 1130 ! These are Port 2 Reflection and reverse transmission. 1140 ! 1150 ! The display will show: 1160 ! 1170 ! MEAS 1 : Port 1 and Port 2 REFLECTION (S11 and S22) 1180 ! MEAS 2 : forward and reverse TRANSMISSION (S21 and S12) 1190 ! 1200 ! Note that a single MEAS channel could be used to gather all four 1210 ! S-parameters after a single sweep. For display convenience 1220 ! however, this program uses both MEAS channels.

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Automated Measurement Setup and Control

Using Single Sweep to Measure and View All Four S-Parameters

1230 ! 1240 DIM A$[10],Data1(1:201) 1250 INTEGER Digits,Bytes 1260 COM /Sys_state/ @Hp87xx,Scode 1270 ! 1280 CALL Iden_port ! Identify I/O Port 1290 ! 1300 OUTPUT @Hp87xx;”SYST:PRES” ! System Preset 1310 OUTPUT @Hp87xx;”*OPC?” 1320 ENTER @Hp87xx;Opc_flag ! Operation complete 1330 ! 1340 ! Select Default Two Port Calibration on MEAS 1 and 2 1350 ! 1360 DISP “Enabling 2-Port Calibration...” 1370 OUTPUT @Hp87xx;”SENS2:STAT ON” ! Turn on MEAS 2 1380 OUTPUT @Hp87xx;”SENS1:FUNC ‘XFR:S 1,1’” ! MEAS 1 = S11 1390 OUTPUT @Hp87xx;”SENS2:FUNC ‘XFR:S 2,1’” ! MEAS 2 = S21 1400 OUTPUT @Hp87xx;”SENS1:CORR:CLASS:SEL DEFAULT2” ! Default 2-Port 1410 OUTPUT @Hp87xx;”SENS2:CORR:CLASS:SEL DEFAULT2” ! Default 2-Port 1420 OUTPUT @Hp87xx;”DISP:FORM ULOW” ! Split Display 1430 OUTPUT @Hp87xx;”*OPC?” 1440 ENTER @Hp87xx;Opc_flag ! Operation complete 1450 DISP ““ 1460 ! 1470 ! Take a single sweep, leaving the analyzer 1480 ! in trigger hold mode. 1490 ! 1500 OUTPUT @Hp87xx;”ABOR;:INIT1:CONT OFF;:INIT1;*WAI” 1510 ! 1520 ! Copy MEAS 1 Data (S11) into MEAS 1 Memory trace 1530 ! Copy MEAS 2 Data (S21) into MEAS 2 Memory trace 1540 ! 1550 DISP “Copy S11 to Mem1” 1560 OUTPUT @Hp87xx;”TRAC CH1SMEM,CH1SDATA” ! Ch1 Data->Mem 1570 DISP “Copy S21 to Mem2” 1580 OUTPUT @Hp87xx;”TRAC CH2SMEM,CH2SDATA” ! Ch2 Data-> Mem 1590 OUTPUT @Hp87xx;”*OPC?” 1600 ENTER @Hp87xx;Opc_flag 1610 ! 1620 ! Now select S22 on MEAS 1 and S12 on MEAS 2. 1630 ! 1640 DISP “Meas S22 on ch1” 1650 OUTPUT @Hp87xx;”SENS1:FUNC ‘XFR:S 2,2’” ! MEAS 1 = S22 1660 OUTPUT @Hp87xx;”*OPC?” 1670 ENTER @Hp87xx;Opc_flag ! Opeation complete. 1680 ! 1690 DISP “Meas S12 on ch2” 1700 OUTPUT @Hp87xx;”SENS2:FUNC ‘XFR:S 1,2’” ! MEAS 2 = S12 1710 OUTPUT @Hp87xx;”*OPC?” 1720 ENTER @Hp87xx;Opc_flag ! Opeation complete. 1730 ! 1740 ! Display Data and Memory on both MEAS channels. Autoscale result. 1750 ! 1760 OUTPUT @Hp87xx;”CALC1:MATH (IMPL);:DISP:WIND1:TRAC1 ON;TRAC2 ON” 1770 OUTPUT @Hp87xx;”DISP:WIND1:TRAC:Y:AUTO ONCE” 1780 OUTPUT @Hp87xx;”CALC2:MATH (IMPL);:DISP:WIND2:TRAC1 ON;TRAC2

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Automated Measurement Setup and Control

Using Single Sweep to Measure and View All Four S-Parameters

ON” 1790 OUTPUT @Hp87xx;”DISP:WIND2:TRAC:Y:AUTO ONCE” 1800 ! 1810 DISP “Ch1: S11 (M:S22) Ch2: S12 (M:S21)” ! Done 1820 BEEP 1830 ! 1840 END 1850 ! 1860 ! 1870 !************************************************************** 1880 ! Iden_port: Identify io port to use 1890 ! Description: This routines sets up the I/O port address for 1900 ! the SCPI interface. For “HP 87xx” instruments, 1910 ! the address assigned to @Hp87xx = 800 otherwise, 1920 ! 716. 1930 !************************************************************** 1940 SUB Iden_port 1950 COM /Sys_state/ @Hp87xx,Scode 1960 ! 1970 IF POS(SYSTEM$(“SYSTEM ID”),”HP 87”)<>0 THEN 1980 ASSIGN @Hp87xx TO 800 1990 Scode=8 2000 ELSE 2010 ASSIGN @Hp87xx TO 716 2020 Scode=7 2030 END IF 2040 ! 2050 SUBEND !Iden_port 2060 !

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Automated Measurement Setup and Control

Autost

AUTOST ﬁles

When IBASIC is used, the measurement control program can be saved as an AUTOST ﬁle on the analyzer's non-volatile RAM disk. When the analyzer's power is turned on, it will ﬁrst check for this ﬁle on the non-volatile RAM disk and then on the 3.5 inch disk, and if found, load it and run it. This feature simpliﬁes the task of turning on an automated test station at the beginning of a working day or test session. To manually load and run an autostart ﬁle, press .

BEGIN

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Automated Measurement Setup and Control

AUTOST ﬁles

5-16 Automating Measurements

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6 Controlling Peripherals

6-1

Page 76

Controlling Peripherals

You can access the analyzer’s rear panel interface ports from your measurement control program. Using this capability, you can communicate with peripherals such as material handlers, custom DUT interface circuits, external switch boxes, and printers.

This chapter will focus on use of the Centronics parallel port and the RS-232 serial port. Communication with the DIN KEYBOARD interface, the USER TTL, and the LIMIT TEST TTL connectors is described in detail in Chapter 3, “Operator Interaction.”

NOTE Refer to your analyzer’s User’s Guide for pinout illustrations and

descriptions of the parallel and serial ports.

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Controlling Peripherals

Using the Parallel Port

The analyzer's parallel (Centronics) port can be used as an 8-bit TTL output port and as a 5-bit TTL input port. The eight TTL outputs are for output only, and cannot be read or used as bi-directional I/O lines. The parallel port does not support the IEEE-1284-deﬁned Extended Capabilities Port (ECP) mode or Enhanced Parallel Port (EPP) mode.

The output signals are driven by standard TTL drivers. They should be buffered for heavy-duty applications to avoid damaging the analyzer. The inputs are standard TTL inputs, designed to accept signals in the 0 V to 5 V range.

The analyzer provides two ways to access the parallel port. You can use the SCPI commands

OUTPUT @Rfna;"DIAG:PORT:WRITE <port>,<register>,<data>

and

OUTPUT @Rfna;"DIAG:PORT:READ? <port>,<register> ENTER @Rfna;Data

or you can use IBASIC and its READIO and WRITEIO commands. See the following tables for more information.

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Controlling Peripherals

Using the Parallel Port

Table 6-1 Writeable Ports

Port

Number

15 0 Outputs 8-bit data to the Cent_D0 thru D7 lines of the Centronics port.

15 1 Sets/clears the user bit according to the least signiﬁcant bit of A. A least

15 2 Sets/clears the limit pass/fail bit according to the least signiﬁcant bit of

15 3 Outputs 8-bit data to the Cent_D0 thru D7 lines of the Centronics port.

9 0 Outputs a byte to the serial port. The byte is output serially according to

Cent_D0 is the least signiﬁcant bit, Cent_D7 is the most signiﬁcant bit. Checks Centronics status lines for:

Out of Paper Printer Not on Line BUSY ACKNOWLEDGE

signiﬁcant bit equal to 1 sets the user bit high. A least signiﬁcant bit of 0 clears the user bit.

A. A least signiﬁcant bit equal to 1 sets the pass/fail bit high. A least signiﬁcant bit of 0 clears the pass/fail bit.

Cent_D0 is the least signiﬁcant bit, Cent_D7 is the most signiﬁcant bit. Sets the Printer_select signal high (de-select). Does not check Centronics status lines.

the conﬁguration for the serial port.

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Table 6-2 Readable Ports

Controlling Peripherals

Using the Parallel Port

Port

Number

9 0 Reads the serial port. 15 0 Reads the 8-bit data port Cent_D0 thru D7. 15 1 Reads the user bit. 15 2 Reads the limit test pass/fail bit. 15 10 Reads the 8-bit status port.

D0 — Cent_acknowledge D1 — Cent_busy D2 — Cent_out_of_paper D3 — Cent_on_line D4 — Cent_printer_err

NOTE When using the WRITEIO(15,0) or WRITEIO(15,3) command, the

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Controlling Peripherals

Using the Parallel Port

Writing to the Parallel Port

To write the value 52 decimal (34 hex, 0011 0100 binary) to the parallel port's output pins, use one of the following commands:

OUTPUT @Rfna;"DIAG:PORT:WRITE 15,3,52" WRITEIO 15,3;52

When the write command is executed, the parallel port's data lines (pins 2-9) will be set to the speciﬁed value, and then a pulse of at least 1 µs duration will occur on the strobe line (pin 1). A data setup and data hold time of at least 1 µs are guaranteed. See Figure 6-1.

Figure 6-1 Writing to the Parallel Port

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Table 6-3 shows the pin numbers, data bus bit numbers, and signal

names:

Table 6-3 Parallel Port Pins

Pin Bit Name

Controlling Peripherals

Using the Parallel Port

1 2 3 4 5 6 7 8 9

N/A D0 D1 D2 D3 D4 D5 D6 D7

Strobe Data 1 Data 2 Data 3 Data 4 Data 5 Data 6 Data 7 Data 8

The data will typically remain valid until the next write to the parallel port, but you should always latch the data using the strobe. Figure 6-2 shows a simple circuit which can be used to write to an 8-bit DAC and a digital latch.

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Controlling Peripherals

Using the Parallel Port

Figure 6-2 Digital Latch Circuit

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Reading from the Parallel Port

The parallel port has ﬁve TTL input signals, normally used for determining the printer's status, which can be read. The signals and the corresponding data bits and pins are shown in the following table:

Table 6-4 Parallel Port Inputs

Pin Bit Name

10 D0 Acknowledge 11 D1 Busy 12 D2 Out of Paper 13 D3 On Line 15 D4 Printer Error

Your custom interface circuit can drive these signals, and they can be read using the following commands.

Controlling Peripherals

Using the Parallel Port

SCPI commands:

OUTPUT @Rfna;"DIAG:PORT:READ? 15,10" ENTER @Rfna;Parallel_in

IBASIC command:

Parallel_in = READIO(15,10)

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Controlling Peripherals

Hardcopy Considerations

The analyzer's feature can send output to printers connected to the parallel port. If you have a custom interface circuit attached to the parallel port, you don't want the hardcopy output to interfere with it.

To address this issue, the analyzer uses the parallel port's printer-select signal (pin 17) to differentiate between hardcopy dumps and user-issued WRITEIO and DIAG:PORT:WRITe commands. During a hardcopy to the parallel port, the printer-select signal is driven low. During WRITEIO and DIAG:PORT:WRITe commands, it is driven high.

Using the printer-select signal, you can connect both an interface circuit and a printer to the parallel port. The interface circuit should only respond to the data strobe (pin 1) when the printer-select signal is high. The printer should only respond to the data strobe when the printer-select signal is low. Most printers require the printer-select line to be low, or else they will not print. Some printers ignore this line. If you are using a printer which ignores this line you have two choices:

1. Consult the printer’s manual to see if there is a DIP-switch setting that controls how the printer responds to the printer-select signal, or if not,

2. Design your interface circuit so that it gates and inhibits the data strobe signal (pin 1) going to the printer when printer-select is high.

Similar to the output signals, you can use the printer-select signal to multiplex the input signals, selecting either the signals from your interface circuit or those from the printer.

HARDCOPY

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Controlling Peripherals

Using the Serial Port

Like the parallel port, the RS-232 serial port can also be accessed using SCPI and IBASIC commands.

To write a byte with a value of 52 decimal (34 hex, 0011 0100 binary) to the serial port, use one of the following commands:

OUTPUT @Rfna;"DIAG:PORT:WRITE 9,0,52" WRITEIO 9,0;52

To read a byte from the serial port, use the following commands:

OUTPUT @Rfna;"DIAG:PORT:READ? 9,0" ENTER @Rfna;Serial_in

If you are using IBASIC, you can simply use the READIO statement:

Serial_in = READIO(9,0)

For general purpose I/O, the parallel port is much easier to interface to than the serial port. To interface to the serial port, a Universal Asynchronous Receiver Transmitter (UART) is typically used to decode the RS-232 signals. Most UARTs are designed to be used with microprocessors.

The advantage of the serial port is that it can operate over long distances: up to 30 meters using the RS-232-C standard. Its disadvantage is its slow speed which is limited to 19200 bits/second.

Before using the serial port, you must select the baud rate and handshake style using the SCPI commands:

SYSTem:COMMunicate:SERial:TRANsmit:BAUD SYSTem:COMMunicate:SERial:TRANsmit:HANDshake {XON|DTR}

One type of application for the serial port is data logging to a remote computer. After each device is measured, an IBASIC program could use the WRITEIO command shown above to send a brief summary of the measurement result, such as a ﬁlter's 3 dB bandwidth and its serial number, to a remote computer. A program on the remote computer would monitor the serial port and read the incoming data and archive it to a hard disk or network.

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Controlling Peripherals

Using the Serial Port

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7 Displaying Measurement

Results

7-1

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Displaying Measurement Results

It is often helpful to eliminate unnecessary and potentially distracting information and annotation from the display, and only show the information necessary to perform a particular task.

The analyzer provides several features to let you customize the information shown on the display as shown in Figure 7-1. Many of the features discussed in this chapter can also be implemented using the analyzer's user interface. See “Customizing the Display” in Chapter 4 of your analyzer’s User’s Guide for more information.

Figure 7-1 Customized Annotation

Customizing features such as limit testing, annotating the X-axis, and using the title feature are described in this chapter.

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Displaying Measurement Results

More Display

Graticule ON off

Graticule On/Off

The graticule is the set of grid lines that designate increments of value on the X-axis and Y-axis of the measurement.

If you are comparing the trace against limit lines or marker values, turning off the graticule makes it easier to view the measurement trace, limit lines, and markers. To turn the graticule off, press

or use the following SCPI

command:

DISPlay:WINDow[1|2]:TRACe:GRATicule:GRID OFF

where the window number is 1 if in full-screen display, and 1 or 2 for the upper and lower split-screen displays.

DISPLAY

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Displaying Measurement Results

Limit Menu

Limit Options

Limit Line ON off

Limit Menu

Limit Options

Limit Icon ON off

Limit Menu

Limit Options

Limit Text ON off

Limit Testing

The measurement trace can be automatically compared to limits which you deﬁne. The limits, entered as lines and points, can be displayed on the screen or can be hidden. Whether or not the limits are displayed, the analyzer will display “PASS” if the measurement satisﬁes the limits and will display the FAIL symbol if the measurement fails to meet the prescribed limits. Using limits gives the operator visual guides when tuning devices, provides standard criteria for meeting device speciﬁcations, and shows an instant indication of the comparison of data versus speciﬁcations.

To turn limit lines on or off

To turn limit lines on or off, press commands:

CALC[1|2]:LIMit:DISPlay ON CALC[1|2]:LIMit:DISPlay OFF

where [1|2] indicates the measurement channel number; use either 1or2.

DISPLAY

, or use the following SCPI

To turn the fail icon on or off

To turn the fail icon on or off, press commands:

DISP:ANN:LIM:ICON[1|2]:FLAG ON DISP:ANN:LIM:ICON[1|2]:FLAG OFF

DISPLAY

, or use the following SCPI

To turn the pass/fail text on or off

To turn the pass/fail text on or off, press commands:

DISP:ANN:LIM:ICON[1|2]:TEXT ON DISP:ANN:LIM:ICON[1|2]:TEXT OFF

DISPLAY

, or use the following SCPI

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Displaying Measurement Results

Limit Menu

Limit Options

Limit Icon X Position

Limit Icon Y Position

Limit Testing

To move the position of the pass/fail indicator

To move the position of the pass/fail indicator, press

, and use the and keys to reposition the indicator. Or use the following SCPI commands:

DISP:ANN:LIM:ICON[1|2]:POS:X <num> DISP:ANN:LIM:ICON[1|2]:POS:Y <num>

For more information on limit lines, see “Using Limit Testing” in Chapter 4 of your analyzer’s User’s Guide.

See Figure 7-1 for an example of a measurement using limit lines with a “PASS” test result.

DISPLAY

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Displaying Measurement Results

Customized X-axis Annotation

X-axis annotation consists of one or two lines of information that appear below the graticule. You can replace this annotation with your own text (see Figure 7-1) or eliminate the X-axis annotation completely.

By default, the X-axis annotation displays the stimulus frequencies (default resolution is kHz), or powers if in power sweep. However, it can be customized using SCPI commands to show your own start and stop X-axis values and units. For example, when measuring mixers which introduce a frequency offset, you can annotate the frequencies at the output of the mixer.

To turn on user-deﬁned X-axis annotation

To turn on user-deﬁned X-axis annotation, use the command:

DISP:ANN:FREQ[1|2]:USER[:STATe] {OFF|0|ON|1}

For example:

DISP:ANN:FREQ1:USER ON

To specify your start and stop values

To specify your start and stop values, use:

DISP:ANN:FREQ[1|2]:USER:STARt <num> DISP:ANN:FREQ[1|2]:USER:STOP <num>

The value <num> must be between −10,000 and 10, 000. For example:

DISP:ANN:FREQ1:USER:STAR -100 DISP:ANN:FREQ1:USER:STOP +100

To specify a custom sufﬁx

To specify a custom sufﬁx, use:

DISP:ANN:FREQ[1|2]:USER:SUFF[:DATA]

For example:

DISP:ANN:FREQ1:USER:SUFF 'uV'

The sufﬁx can be up to 3 characters long.

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Displaying Measurement Results

More Display

Annotation Options

Freq Annot ON off

Customized X-axis Annotation

To turn the X-axis annotation on or off

To turn the X-axis (frequency) annotation on or off, press the following SCPI commands:

DISP:ANN:FREQ[1|2] ON DISP:ANN:FREQ[1|2] OFF

NOTE When using custom X-axis annotation, the SCPI command

CALC:MARK:X and query CALC:MARK:X? will return the analyzer's stimulus value, not your custom annotation values. If this is a problem, you can use the SCPI command CALC:MARK:POIN to specify the X-axis point number at which you wish to position the marker.

For example:

OUTPUT @HP8711;"CALC:MARK1:POIN 134"

will put the marker at point number 134. Custom X-axis annotation has no effect on Y-axis marker values

(CALC:MARK:Y?).

DISPLAY

or use

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Displaying Measurement Results

Customized Measurement-Channel Annotation

The analyzer displays measurement-channel annotation above the graticule. This annotation shows the measurement type, format, scale/division, and reference level.

You may replace this annotation with your own text (see Figure 7-1) or eliminate the measurement-channel annotation completely.

T o turn on user-deﬁned measurement-channel annotation

To turn on user-deﬁned measurement-channel annotation, use the command:

DISP:ANN:CHAN[1|2]:USER[:STATe] ON

where [1|2]indicates the measurement-channel number: either 1 or 2.

To specify the string to be displayed

To specify the string to be displayed use the command:

DISP:ANN:CHAN[1|2]:USER:LAB[:DATA]

For example:

DISP:ANN:CHAN1:USER:LABel '1: SuperNotch filter, test #3'

To restore default measurement-channel annotation

To restore the default measurement-channel annotation, use:

DISP:ANN:CHAN[1|2]:USER OFF

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Displaying Measurement Results

More Display

Annotation Options

Meas Annot ON off

Customized Measurement-Channel Annotation

To turn measurement-channel annotation on or off

To turn the measurement-channel annotation on or off , press the following SCPI commands:

DISP:ANN:CHAN[1|2] ON DISP:ANN:CHAN[1|2] OFF

DISPLAY

, or use

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Displaying Measurement Results

Markers

Well-designed use of the analyzer’s marker features in an automated system can enhance the data gathering process, as well as provide important visual feedback to the operator.

The active marker's value is displayed in the upper right area of the graticule. If marker bandwidth (or notch) search is selected, the bandwidth (or notch) information is displayed instead. This marker information can be used to view exact measured data at critical frequency points. Note the customized measurement channel notation in

Figure 7-1. In addition to the active marker's readout, four of the

marker's values are displayed in the softkey area during front panel use. This makes it easy to quickly read the measured data at several marker positions.

The triangular marker symbols can also be used to graphically indicate critical frequency points of the measurement. For example , a marker can be set at the desired center frequency for a notch ﬁlter, and the operator can tune the ﬁlter until the notch is at the same frequency as the marker.

Marker search types include:

• max search

• min search

• target search

• bandwidth

• notch

• multi peak

• multi notch When marker tracking is turned on, these searches will be automatically

performed at the end of each sweep. This can be useful in tuning applications.

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Displaying Measurement Results

Markers

Other marker functions that can be useful are the marker math functions:

• statistics

• ﬂatness

• RF ﬁlter stats These functions perform certain mathematical calculations on the

amplitude, phase, delay or SWR data of user -deﬁned trace segments . See “To Use Marker Math Functions” in Chapter 4 of your analyzer’s User’s Guide for more information on these features.

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Displaying Measurement Results

More Display

Title and Clock

Title Line 1

Title and Clock

The analyzer has two 30-character title lines. One of these lines can be replaced with a real-time clock readout. Timestamps on measurement data can be important when monitoring throughput, quality, and processes.

For example , the title line can be set to show the serial number and type of the DUT. Doing so provides a simple and safe link between the device under test and the measurement data.

The title and clock lines are, by default, included on hardcopy printouts. These can be conﬁgured using the

example, refer to “Using the Analyzer's Title Feature” on page 3-15.

DISPLAY

menu. For more details and a simple

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8 Saving Measurement Results

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Saving Measurement Results

After measuring a device, you will probably want to save the measurement results so that you can perform statistical analyses on them. Statistical quality control (SQC) can be a powerful tool to indicate process drift or variation.

You may also want to produce a print or plot of the DUT's response, and ship this to your customer along with the DUT.

8-2 Automating Measurements