Agilent 86100A Programmer’s Guide

DCA and DCA-J

Agilent 86100A/B/C Wide-Bandwidth Oscilloscope Programmer’s Guide

Notices

No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright lays.

Manual Part Number

86100-90065

Edition

First edition, February 2004

Printed in Malaysia

Agilent Technologies, Inc. Digital Signal Analysis Division 1400 Fountaingrove Parkway Santa Rosa, CA 95403, USA

Warranty

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

Technology Licenses

The hardware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Departments and Agencies of the U.S. Government will receive no greater than Restricted Rights as defined in FAR

52.227-19(c)(1-2) (June 1987). U.S. Government users will receive no greater than Limited Rights as defined in FAR

52.227-14 (June 1987) or DFAR 252.2277015 (b)(2) (November 1995), as applicable in any technical data.

Safety Notices

CAUTION

Caution denotes a hazard. It calls attention to a procedure which, if not correctly performed or adhered to, could result in damage to or destruction of the product. Do not proceed beyond a caution sign until the indicated conditions are fully understood and met.

WARNING

Warning denotes a hazard. It calls attention to a procedure which, if not correctly performed or adhered to, could result in injury or loss of life. Do not proceed beyond a warning sign until the indicated conditions are fully understood and met.

LZW compression/decompression: Licensed under U.S. Patent No. 4,558,302 and foreign counterparts. The purchase or use of LZW graphics capability in a licensed product does not authorize or permit an end user to use any other product or perform any other method or activity involving use of LZW unless the end user is separately licensed in writing by Unisys.

Restricted Rights Legend

If software is for use in the performance of a U.S. Government prime contract or subcontract, Software is delivered and licensed as “Commercial computer software” as defined in DFAR 252.227-7014 (June 1995), or as a “commercial item” as defined in FAR 2.101(a) or as “Restricted computer software” as defined in FAR

52.227-19 (June 1987) or any equivalent agency regulation or contract clause. Use, duplication or disclosure of Software is subject to Agilent Technologies’ standard commercial license terms, and non-DOD

Contents

1Introduction

Getting Started Programming 1-12 Interface Functions 1-17 Status Reporting 1-20 Message Communication and System Functions 1-34 Programming Conventions 1-37 Multiple Databases 1-47 Language Compatibility 1-50 New and Revised Commands 1-56 Commands Unavailable in Jitter Mode 1-58 Error Messages 1-60

2Sample Programs

Sample Program Structure 2-3 Sample C Programs 2-4 Listings of the Sample Programs 2-20

3 Common Commands

4 Root Level Commands

5 System Commands

6 Acquire Commands

7 Calibration Commands

8 Channel Commands

9 Clock Recovery Commands

10 Disk Commands

11 Display Commands

12 Function Commands

Contents-1

Contents

13 Hardcopy Commands

14 Histogram Commands

15 Limit Test Commands

16 Marker Commands

17 Mask Test Commands

18 Measure Commands

19 TDR/TDT Commands

20 Timebase Commands

21 Trigger Commands

22 Waveform Commands

23 Waveform Memory Commands

Contents-2

Introduction

This chapter introduces the basics for remote programming of an analyzer. The programming commands in this manual conform to the IEEE 488.2 Standard Digital Interface for Programmable Instrumentation. The programming commands provide the means of remote control.

Basic operations that you can do with a computer (GPIB controller) and an analyzer include:

• Set up the analyzer.

• Make measurements.

• Get data (waveform, measurements, configuration) from the analyzer.

• Send information, such as waveforms and configurations, to the analyzer.

Communicating with the Analyzer

Other tasks are accomplished by combining these functions.

Example Programs are Written in HP BASIC and C

The programming examples for individual commands in this manual are written in HP BASIC and C.

Computers communicate with the analyzer by sending and receiving messages over a remote interface, usually with GPIB programming. Commands for programming normally appear as ASCII character strings embedded in the output statements of a “host” language available on your computer. The input commands of the host language are used to read in responses from the analyzer.

For example, HP BASIC uses the OUTPUT statement for sending commands and queries. After a query is sent, the response is usually read using the HP BASIC ENTER statement. The ENTER statement passes the value across the bus to the computer and places it in the designated variable.

For the GPIB interface, messages are placed on the bus using an output command and passing the device address, program message, and a terminator. Passing the device address ensures that the program message is sent to the correct GPIB interface and GPIB device.

This HP BASIC OUTPUT statement sends a command that sets the channel 1 scale value to 500 mV:

1-2

Introduction

OUTPUT <device address>;":CHANNEL1:SCALE 500E-3"<terminator>

The device address represents the address of the device being programmed. Each of the other parts of the above statement are explained in the following pages.

Use the Suffix Multiplier Instead

Using "mV" or "V" following the numeric voltage value in some commands will cause Error 138–Suffix not allowed. Instead, use the convention for the suffix multiplier as described in “Message Communication and System Functions” on page 1-34.

Output Command The output command depends entirely on the programming language. Throughout this

book, HP BASIC and ANSI C are used in the examples of individual commands. If you are using other languages, you will need to find the equivalents of HP BASIC commands like OUTPUT, ENTER, and CLEAR, to convert the examples.

Device Address The location where the device address must be specified depends on the programming

language you are using. In some languages, it may be specified outside the OUTPUT command. In HP BASIC, it is always specified after the keyword OUTPUT. The examples in this manual assume that the analyzer and interface card are at GPIB device address 707. When writing programs, the device address varies according to how the bus is configured.

Instructions Instructions, both commands and queries, normally appear as strings embedded in a

statement of your host language, such as HP BASIC, Pascal, or C. The only time a parameter is not meant to be expressed as a string is when the instruction's syntax definition specifies <block data>, such as HP BASIC’s "learnstring" command. There are only a few instructions that use block data.

Instructions are composed of two main parts:

• The header, which specifies the command or query to be sent.

• The program data, which provides additional information to clarify the meaning of the instruction.

Instruction Header

The instruction header is one or more command mnemonics separated by colons (:) that represent the operation to be performed by the analyzer. See “Programming Conventions” on page 1-37 for more information.

Queries are formed by adding a question mark (?) to the end of the header. Many instructions can be used as either commands or queries, depending on whether or not you include the question mark. The command and query forms of an instruction usually have different program data. Many queries do not use any program data.

1-3

Introduction

White Space (Separator)

White space is used to separate the instruction header from the program data. If the instruction does not require any program data parameters, you do not need to include any white space. In this manual, white space is defined as one or more spaces. ASCII defines a space to be character 32, in decimal.

Program Data Program data is used to clarify the meaning of the command or query. It provides nec-

essary information, such as whether a function should be on or off or which waveform is to be displayed. Each instruction's syntax definition shows the program data, and the values they accept. See “Numeric Program Data” on page 1-7 for more information about general syntax rules and acceptable values.

When there is more than one data parameter, they are separated by commas (,). You can add spaces around the commas to improve readability.

Header Types There are three types of headers:

• Simple Command headers

• Compound Command headers

• Common Command headers

Simple Command Header

Simple command headers contain a single mnemonic. AUTOSCALE and DIGITIZE are examples of simple command headers typically used in this analyzer. The syntax is:

OUTPUT 707;”:AUTOSCALE”

When program data must be included with the simple command header (for example, :DIGITIZE CHAN1), white space is added to separate the data from the header. The syntax is:

OUTPUT 707;”:DIGITIZE CHANNEL1,FUNCTION2”

Compound Command Header

Compound command headers are a combination of two program mnemonics. The first mnemonic selects the subsystem, and the second mnemonic selects the function within that subsystem. The mnemonics within the compound message are separated by colons. For example:

To execute a single function within a subsystem:

:<subsystem>:<function><separator><program data><terminator>

For example:

1-4

Introduction

OUTPUT 707;”:CHANNEL1:BANDWIDTH HIGH”

Combining Commands in the Same Subsystem

To execute more than one command within the same subsystem, use a semi-colon (;) to separate the commands:

:<subsystem>:<command><separator><data>;<command><separator><data><terminator>

For example:

:CHANNEL1:DISPLAY ON;BWLIMIT ON

Common Command Header

Common command headers, such as clear status, control the IEEE 488.2 functions within the analyzer. The syntax is:

*<command header><terminator>

No space or separator is allowed between the asterisk (*) and the command header. *CLS is an example of a common command header.

Duplicate Mnemonics

Identical function mnemonics can be used for more than one subsystem. For example, the function mnemonic RANGE may be used to change the vertical range or to change the horizontal range.

To set the vertical range of channel 1 to 0.4 volts full scale:

:CHANNEL1:RANGE .4

To set the horizontal time base to 1 second full scale:

:TIMEBASE:RANGE 1

CHANNEL1 and TIMEBASE are subsystem selectors, and determine which range is being modified.

Query Headers Command headers immediately followed by a question mark (?) are queries. After

receiving a query, the analyzer interrogates the requested subsystem and places the answer in its output queue. The answer remains in the output queue until it is read or until another command is issued. When read, the answer is transmitted across the bus to the designated listener (typically a computer). For example, the query:

:TIMEBASE:RANGE?

places the current time base setting in the output queue.

In HP BASIC, the computer input statement:

ENTER < device address >;Range

1-5

Introduction

passes the value across the bus to the computer and places it in the variable Range.

You can use query commands to find out how the analyzer is currently configured. They are also used to get results of measurements made by the analyzer. For example, the command:

:MEASURE:RISETIME?

tells the analyzer to measure the rise time of your waveform and place the result in the output queue.

The output queue must be read before the next program message is sent. For example, when you send the query :MEASURE:RISETIME? you must follow it with an input statement. In HP BASIC, this is usually done with an ENTER statement immediately followed by a variable name. This statement reads the result of the query and places the result in a specified variable.

Handling Queries Properly

If you send another command or query before reading the result of a query, the output buffer is cleared and the current response is lost. This also generates a query-interrupted error in the error queue. If you execute an input statement before you send a query, it will cause the computer to wait indefinitely.

Program Header Options

You can send program headers using any combination of uppercase or lowercase ASCII characters. Analyzer responses, however, are always returned in uppercase.

You may send program command and query headers in either long form (complete spelling), short form (abbreviated spelling), or any combination of long form and short form. For example:

:TIMEBASE:DELAY 1E-6 is the long form. :TIM:DEL 1E-6 is the short form.

Using Long Form or Short Form

Programs written in long form are easily read and are almost self-documenting. The short form syntax conserves the amount of computer memory needed for program storage and reduces I/O activity.

The rules for the short form syntax are described in “Programming Conventions” on page 1-37.

1-6

Introduction

Character Program Data

Numeric Program Data

Character program data is used to convey parameter information as alpha or alphanumeric strings. For example, the :TIMEBASE:REFERENCE command can be set to left, center, or right. The character program data in this case may be LEFT, CENTER, or RIGHT. The command :TIMEBASE:REFERENCE RIGHT sets the time base reference to right.

The available mnemonics for character program data are always included with the instruction's syntax definition. Either the long form of commands, or the short form (if one exists), may be sent. Uppercase and lowercase letters may be mixed freely. When receiving responses, uppercase letters are used exclusively.

Some command headers require program data to be expressed numerically. For example, :TIMEBASE:RANGE requires the desired full scale range to be expressed numerically.

For numeric program data, you can use exponential notation or suffix multipliers to indicate the numeric value. The following numbers are all equal:

28 = 0.28E2 = 280E-1 = 28000m = 0.028K = 28E-3K

When a syntax definition specifies that a number is an integer, it means that the number should be whole. Any fractional part is ignored and truncated. Numeric data parameters that accept fractional values are called real numbers. For more information see “Interface Functions” on page 1-17.

All numbers are expected to be strings of ASCII characters.

• When sending the number 9, you would send a byte representing the ASCII code for the character “9” (which is 57).

Embedded Strings

Program Message Terminator

• A three-digit number like 102 would take up three bytes (ASCII codes 49, 48, and 50). The number of bytes is figured automatically when you include the entire instruction in a string.

Embedded strings contain groups of alphanumeric characters which are treated as a unit of data by the analyzer. An example of this is the line of text written to the advisory line of the analyzer with the :SYSTEM:DSP command:

:SYSTEM:DSP ""This is a message.""

You may delimit embedded strings with either single (') or double (") quotation marks. These strings are case-sensitive, and spaces act as legal characters just like any other character.

The program instructions within a data message are executed after the program message terminator is received. The terminator may be either a NL (New Line) character, an EOI (End-Or-Identify) asserted in the GPIB interface, or a combination of the two. Asserting the EOI sets the EOI control line low on the last byte of the data message. The NL character is an ASCII linefeed (decimal 10).

1-7

Introduction

New Line Terminator Functions Like EOS and EOT

The NL (New Line) terminator has the same function as an EOS (End Of String) and EOT (End Of Text) terminator.

Common Commands within a Subsystem

Selecting Multiple Subsystems

Common commands can be received and processed by the analyzer whether they are sent over the bus as separate program messages or within other program messages. If you have selected a subsystem, and a common command is received by the analyzer, the analyzer remains in the selected subsystem. For example, if the program message

":ACQUIRE:AVERAGE ON;*CLS;COUNT 1024"

is received by the analyzer, the analyzer turns averaging on, then clears the status information without leaving the selected subsystem.

If some other type of command is received within a program message, you must reenter the original subsystem after the command. For example, the program message

":ACQUIRE:AVERAGE ON;:AUTOSCALE;:ACQUIRE:AVERAGE:COUNT 1024"

turns averaging on, completes the autoscale operation, then sets the acquire average count. In this example, :ACQUIRE must be sent again after the AUTOSCALE command to re-enter the ACQUIRE subsystem and set count.

You can send multiple program commands and program queries for different subsystems on the same line by separating each command with a semicolon. The colon following the semicolon lets you enter a new subsystem. For example:

:CHANNEL1:RANGE 0.4;:TIMEBASE:RANGE 1

You Can Combine Compound and Simple Commands

Multiple commands may be any combination of compound and simple commands.

File Names and Types

When specifying a file name in a remote command, enclose the name in double quotation marks, such as "filename". If you specify a path, the path should be included in the quotation marks.

You can use the full path name, a relative path name, or no path. For example, you can specify:

• a full path name: "D:\User Files\waveforms\channel2.wfm"

• a relative path name: "..\myfile.set" or “.\screen1.jpg”

• a simple file name: "Memory1.txt"

1-8

Introduction

All files stored using remote commands have file name extensions.The following table shows the file name extension used for each file type.

Table 1-1. File Name Extensions

File Type File Name Extension

Waveform - internal format .wfm

Waveform - text format (Verbose or Y values) .txt

Setup .set

Color grade - Gray Scale .cgs

Jitter Memory .jd

Screen image .bmp, .eps, .gif, .pcx, .ps, .jpg, .tif

Mask .msk, .pcm

TDR/TDT .tdr

If you do not specify an extension when storing a file, or specify an incorrect extension, it will be corrected automatically according to the following rules:

• No extension specified: add the extension for the file type.

• Extension does not match file type: retain the filename, (including the current extension) and add the appropriate extension.

You do not need to use an extension when loading a file if you use the optional destination parameter. For example, :DISK:LOAD "STM1_OC3",SMASK will automatically add .msk to the file name.

Note

For .gif and .tif file formats, this instrument uses LZW compression/decompression licensed under U.S. patent No 4,558,302 and foreign counterparts. End user should not modify, copy, or distribute LZW compression/decompression capability.

For .jpg file format, this instrument uses the .jpg software written by the Independent JPEG Group.

1-9

Introduction

The following table shows the rules used when loading a specified file.

Table 1-2. Rules for Loading Files

File Name Extension Destination Rule

No extension Not specified Default to internal waveform format; add .wfm

extension

Extension does not match file type

Extension matches file type Not specified Use file name with no alterations; destination is

No extension Specified Add extension for destination type; default for

Extension does not match destination file type

Extension matches destination file type

Not specified Default to internal waveform format; add .wfm

extension

based on extension file type

waveforms is internal format (.wfm)

Specified Retain file name; add extension for destination

type. Default for waveforms is internal format (.wfm)

Specified Retain file name; destination is as specified

Note

ASCII waveform files can be loaded only if the file name explicitly includes the .txt extension.

File Locations If you don’t specify a directory when storing a file, the location of the file will be based

on the file type. The following table shows the default locations for storing files. On 86100C instruments, files are stored on the D: drive. On 86100A/B instruments, files are stored on the C: drive.

Table 1-3. Default File Locations for Storing Files (1 of 2)

File Type Default Location

Waveform - internal format D:\User Files\waveforms

Waveform - text format (Verbose or Y values) D:\User Files\waveforms

Setup D:\User Files\setups

Color Grade - Gray Scale D:\User Files\colorgrade-grayscale

Jitter Memory D:\User Files\jitter data

Screen Image D:\User Files\screen images

Mask C:\Scope\masks (standard masks)

D:\User Files\masks (user-defined masks)

1-10

Introduction

Table 1-3. Default File Locations for Storing Files (2 of 2)

File Type Default Location

TDR/TDT calibration data D:\User Files\TDR normalization

When loading a file, you can specify the full path name, a relative path name, or no path name. The following table shows the rules for locating files, based on the path specified.

Table 1-4. File Locations (Loading Files)

File Name Rule

Full path name Use file name and path specified

Relative path name Full path name is formed relative to the present

working directory, set with the command :DISK:CDIR. The present working directory can be read with the query :DISK:PWD?

File name with no preceding path Add the file name to the default path

(D:\User Files) based on the file type.

Standard masks loaded from C:\Scope\masks. Files may be stored to or loaded from any path external drive or on any mapped network drive.

1-11

Introduction

Getting Started Programming

The remainder of this chapter discusses how to set up the analyzer, how to retrieve setup information and measurement results, how to digitize a waveform, and how to pass data to the computer. Chapter 18, “Measure Commands” describes sending measurement data to the analyzer.

Initialization To make sure the bus and all appropriate interfaces are in a known state, begin every

program with an initialization statement. For example, HP BASIC provides a CLEAR command which clears the interface buffer:

CLEAR 707 ! initializes the interface of the analyzer

When you are using GPIB, CLEAR also resets the analyzer's parser. The parser is the program that reads in the instructions you send.

After clearing the interface, initialize the analyzer to a preset state:

OUTPUT 707;"*RST" ! initializes the analyzer to a preset state

Initializing the analyzer

The commands and syntax for initializing the analyzer are discussed in Chapter 3, “Common Commands”. Refer to your GPIB manual and programming language reference manual for information on initializing the interface.

Autoscale

The AUTOSCALE feature of Agilent Technologies digitizing analyzers performs a very useful function on unknown waveforms by automatically setting up the vertical channel, time base, and trigger level of the analyzer.

The syntax for the autoscale function is:

:AUTOSCALE<terminator>

Setting Up the Analyzer

A typical analyzer setup configures the vertical range and offset voltage, the horizontal range, delay time, delay reference, trigger mode, trigger level, and slope.

A typical example of the commands sent to the analyzer are:

:CHANNEL1:RANGE 16;OFFSET 1.00<terminator> :SYSTEM:HEADER OFF<terminator> :TIMEBASE:RANGE 1E-3;DELAY 100E-6<terminator>

1-12

Introduction

Getting Started Programming

This example sets the time base at 1 ms full-scale (100 µs/div), with delay of 100 µs. Vertical is set to 16 V full-scale (2 V/div), with center of screen at 1 V, and probe attenuation of 10.

Example Program This program demonstrates the basic command structure used to program the ana-

lyzer.

10 CLEAR 707 ! Initialize analyzer interface 20 OUTPUT 707;"*RST" !Initialize analyzer to preset state 30 OUTPUT 707;":TIMEBASE:RANGE 5E-4"! Time base to 500 us full scale 40 OUTPUT 707;":TIMEBASE:DELAY 25E-9"! Delay to 25 ns 50 OUTPUT 707;":TIMEBASE:REFERENCE CENTER"! Display reference at center 60 OUTPUT 707;":CHANNEL1:RANGE .16"! Vertical range to 160 mV full scale 70 OUTPUT 707;":CHANNEL1:OFFSET -.04"! Offset to -40 mV 80 OUTPUT 707;":TRIGGER:LEVEL,-.4"! Trigger level to -0.4 90 OUTPUT 707;":TRIGGER:SLOPE POSITIVE"! Trigger on positive slope 100 OUTPUT 707;":SYSTEM:HEADER OFF"<terminator> 110 OUTPUT 707;":DISPLAY:GRATICULE FRAME"! Grid off 120 END

Overview of the Program

• Line 10 initializes the analyzer interface to a known state.

• Line 20 initializes the analyzer to a preset state.

Using the DIGITIZE Command

• Lines 30 through 50 set the time base, the horizontal time at 500

µs full scale,

and 25 ns of delay referenced at the center of the graticule.

• Lines 60 through 70 set the vertical range to 160 millivolts full scale and the center screen at

• Lines 80 through 90 configure the analyzer to trigger at

−40 millivolts.

−0.4 volts with normal

triggering.

• Line 100 turns system headers off.

• Line 110 turns the grid off.

The DIGITIZE command is a macro that captures data using the acquisition (ACQUIRE) subsystem. When the digitize process is complete, the acquisition is stopped. The captured data can then be measured by the analyzer or transferred to the computer for further analysis. The captured data consists of two parts: the preamble and the waveform data record.

After changing the analyzer configuration, the waveform buffers are cleared. Before doing a measurement, the DIGITIZE command should be sent to ensure new data has been collected.

You can send the DIGITIZE command with no parameters for a higher throughput. Refer to the DIGITIZE command in Chapter 4, “Root Level Commands” for details.

1-13

Introduction

Getting Started Programming

When the DIGITIZE command is sent to an analyzer, the specified channel’s waveform is digitized with the current ACQUIRE parameters. Before sending the :WAVEFORM:DATA? query to get waveform data, specify the WAVEFORM parameters.

The number of data points comprising a waveform varies according to the number requested in the ACQUIRE subsystem. The ACQUIRE subsystem determines the number of data points, type of acquisition, and number of averages used by the DIGITIZE command. This allows you to specify exactly what the digitized information contains. The following program example shows a typical setup:

OUTPUT 707;":SYSTEM:HEADER OFF"<terminator> OUTPUT 707;":WAVEFORM:SOURCE CHANNEL1"<terminator> OUTPUT 707;":WAVEFORM:FORMAT BYTE"<terminator> OUTPUT 707;":ACQUIRE:COUNT 8"<terminator> OUTPUT 707;":ACQUIRE:POINTS 500"<terminator> OUTPUT 707;":DIGITIZE CHANNEL1"<terminator> OUTPUT 707;":WAVEFORM:DATA?"<terminator>

This setup places the analyzer to acquire eight averages. This means that when the DIGITIZE command is received, the command will execute until the waveform has been averaged at least eight times.

After receiving the :WAVEFORM:DATA? query, the analyzer will start passing the waveform information when queried.

Digitized waveforms are passed from the analyzer to the computer by sending a numerical representation of each digitized point. The format of the numerical representation is controlled with the :WAVEFORM:FORMAT command and may be selected as BYTE, WORD, or ASCII.

The easiest method of entering a digitized waveform depends on data structures, available formatting, and I/O capabilities. You must scale the integers to determine the voltage value of each point. These integers are passed starting with the leftmost point on the analyzer's display. For more information, refer to Chapter 22, “Waveform Commands”.

When using GPIB, a digitize operation may be aborted by sending a Device Clear over the bus (for example, CLEAR 707).

Receiving Information from the Analyzer

Note

The execution of the DIGITIZE command is subordinate to the status of ongoing limit tests. (See commands ACQuire:RUNTil on page 6-5, MTEST:RUNTil on page 17-10, and LTEST:RUNTil on page 15-5.) The DIGITIZE command will not capture data if the stop condition for a limit test has been met.

After receiving a query (command header followed by a question mark), the analyzer places the answer in its output queue. The answer remains in the output queue until it is read or until another command is issued. When read, the answer is transmitted across the interface to the computer. The input statement for receiving a response

1-14

Introduction

Getting Started Programming

message from an analyzer's output queue typically has two parameters; the device address and a format specification for handling the response message. For example, to read the result of the query command :CHANNEL1:RANGE? you would execute the HP BASIC statement:

ENTER <device address>;Setting$

The device address parameter represents the address of the analyzer. This would enter the current setting for the range in the string variable Setting$.

All results for queries sent in a program message must be read before another program message is sent. For example, when you send the query :MEASURE:RISETIME?, you must follow that query with an input statement. In HP BASIC, this is usually done with an ENTER statement.

Handling Queries Properly

If you send another command or query before reading the result of a query, the output buffer will be cleared and the current response will be lost. This will also generate a query-interrupted error in the error queue. If you execute an input statement before you send a query, it will cause the computer to wait indefinitely.

The format specification for handling response messages depends on both the computer and the programming language.

String Variable Example

Numeric Variable Example

The output of the analyzer may be numeric or character data, depending on what is queried. Refer to the specific commands for the formats and types of data returned from queries.

For the example programs, assume that the device being programmed is at device address 707. The actual address depends on how you have configured the bus for your own application.

In HP BASIC 5.0, string variables are case-sensitive, and must be expressed exactly the same way each time they are used. This example shows the data being returned to a string variable:

10 DIM Rang$[30] 20 OUTPUT 707;":CHANNEL1:RANGE?" 30 ENTER 707;Rang$ 40 PRINT Rang$ 50 END

After running this program, the computer displays:

+8.00000E-01

This example shows the data being returned to a numeric variable:

10 OUTPUT 707;":CHANNEL1:RANGE?" 20 ENTER 707;Rang

1-15

Introduction

Getting Started Programming

30 PRINT Rang 40 END

After running this program, the computer displays:

Definite-Length Block Response Data

Definite-length block response data allows any type of device-dependent data to be transmitted over the system interface as a series of 8-bit binary data bytes. This is particularly useful for sending large quantities of data or 8-bit extended ASCII codes. The syntax is a pound sign (#) followed by a non-zero digit representing the number of digits in the decimal integer. After the non-zero digit is the decimal integer that states the number of 8-bit data bytes being sent. This is followed by the actual data.

For example, for transmitting 4000 bytes of data, the syntax would be:

#44000 <4000 bytes of data> <terminator>

The leftmost “4” represents the number of digits in the number of bytes, and “4000” represents the number of bytes to be transmitted.

Multiple Queries You can send multiple queries to the analyzer within a single program message, but you

must also read them back within a single program message. This can be accomplished by either reading them back into a string variable or into multiple numeric variables. For example, you could read the result of the query :TIMEBASE:RANGE?;DELAY? into the string variable Results$ with the command:

ENTER 707;Results$

When you read the result of multiple queries into string variables, each response is separated by a semicolon. For example, the response of the query :TIMEBASE:RANGE?;DELAY? would be:

<range_value>;<delay_value>

Use the following program message to read the query :TIMEBASE:RANGE?;DELAY? into multiple numeric variables:

ENTER 707;Result1,Result2

Analyzer Status Status registers track the current status of the analyzer. By checking the analyzer sta-

tus, you can find out whether an operation has completed, is receiving triggers, and more. “Status Reporting” on page 1-20 explains how to check the status of the analyzer.

1-16

Introduction

Interface Functions

The interface functions deal with general bus management issues, as well as messages that can be sent over the bus as bus commands. In general, these functions are defined by IEEE 488.1.

GPIB Interface Connector

The analyzer is equipped with a GPIB interface connector on the rear panel. This allows direct connection to a GPIB equipped computer. You can connect an external GPIB compatible device to the analyzer by installing a GPIB cable between the two units. Finger tighten the captive screws on both ends of the GPIB cable to avoid accidentally disconnecting the cable during operation.

A maximum of fifteen GPIB compatible instruments (including a computer) can be interconnected in a system by stacking connectors. This allows the analyzers to be connected in virtually any configuration, as long as there is a path from the computer to every device operating on the bus.

CAUTION Avoid stacking more than three or four cables on any one connector. Multiple

connectors produce leverage that can damage a connector mounting.

GPIB Default Startup Conditions

The following default GPIB conditions are established during power-up: 1) The Request Service (RQS) bit in the status byte register is set to zero. 2) All of the event registers, the Standard Event Status Enable Register, Service Request Enable Register, and the Status Byte Register are cleared.

1-17

Introduction

Interface Functions

Interface Capabilities

The interface capabilities of this analyzer, as defined by IEEE 488.1, are listed in the following table.

Table 1-5. Interface Capabilities

Code Interface Function Capability

SH1 Source Handshake Full Capability

AH1 Acceptor Handshake Full Capability

T5 Talker Basic Talker/Serial Poll/Talk Only Mode/

Unaddress if Listen Address (MLA)

L4 Listener Basic Listener/

Unaddresses if Talk Address (MTA)

SR1 Service Request Full Capability

RL1 Remote Local Complete Capability

PP1 Parallel Poll Remote Configuration

DC1 Device Clear Full Capability

DT1 Device Trigger Full Capability

C0 Computer No Capability

E2 Driver Electronics Tri State (1 MB/SEC MAX)

Command and Data Concepts

Communicating Over the Bus

The GPIB has two modes of operation, command mode and data mode. The bus is in the command mode when the Attention (ATN) control line is true. The command mode is used to send talk and listen addresses and various bus commands such as group execute trigger (GET).

The bus is in the data mode when the ATN line is false. The data mode is used to convey device-dependent messages across the bus. The device-dependent messages include all of the analyzer specific commands, queries, and responses found in this manual, including analyzer status information.

Device addresses are sent by the computer in the command mode to specify who talks and who listens. Because GPIB can address multiple devices through the same interface card, the device address passed with the program message must include the correct interface select code and the correct analyzer address.

Device Address = (Interface Select Code * 100) + (Analyzer Address)

1-18

Introduction

Interface Functions

The Analyzer is at Address 707 in Examples

The examples in this manual assume that the analyzer is at device address 707.

Interface Select Code

Each interface card has a unique interface select code. This code is used by the computer to direct commands and communications to the proper interface. The default is typically “7” for GPIB interface cards.

Analyzer Address

Each analyzer on the GPIB must have a unique analyzer address between decimal 0 and 30. This analyzer address is used by the computer to direct commands and communications to the proper analyzer on an interface. The default is typically “7” for this analyzer. You can change the analyzer address in the Utilities, Remote Interface dialog box.

Do Not Use Address 21 for an Analyzer Address

Address 21 is usually reserved for the Computer interface Talk/Listen address and should not be used as an analyzer address.

Bus Commands

The following commands are IEEE 488.1 bus commands (ATN true). IEEE 488.2 defines many of the actions that are taken when these commands are received by the analyzer.

Device Clear

The device clear (DCL) and selected device clear (SDC) commands clear the input buffer and output queue, reset the parser, and clear any pending commands. If either of these commands is sent during a digitize operation, the digitize operation is aborted.

Group Execute Trigger

The group execute trigger (GET) command arms the trigger. This is the same action produced by sending the RUN command.

Interface Clear

The interface clear (IFC) command halts all bus activity. This includes unaddressing all listeners and the talker, disabling serial poll on all devices, and returning control to the system computer.

1-19

Introduction

Status Reporting

An overview of the analyzer's status reporting structure is shown in the following figure. The status reporting structure shows you how to monitor specific events in the analyzer. Monitoring these events allows determination of the status of an operation, the availability and reliability of the measured data, and more.

• To monitor an event, first clear the event, then enable the event. All of the events are cleared when you initialize the analyzer.

• To generate a service request (SRQ) interrupt to an external computer, enable at least one bit in the Status Byte Register.

The Status Byte Register, the Standard Event Status Register group, and the Output Queue are defined as the Standard Status Data Structure Model in IEEE 488.2-1987. IEEE 488.2 defines data structures, commands, and common bit definitions for status reporting. There are also analyzer-defined structures and bits.

Status Reporting Data Structures

The different status reporting data structures, descriptions, and interactions are shown in the following figure. To make it possible for any of the Standard Event Status Register bits to generate a summary bit, the corresponding bits must be enabled. These bits are enabled by using the *ESE common command to set the corresponding bit in the Standard Event Status Enable Register.

To generate a service request (SRQ) interrupt to the computer, at least one bit in the Status Byte Register must be enabled. These bits are enabled by using the *SRE common command to set the corresponding bit in the Service Request Enable Register. These enabled bits can then set RQS and MSS (bit 6) in the Status Byte Register.

For more information about common commands, see Chapter 3, “Common Commands”.

1-20

Introduction

Status Reporting

Figure 1-1. Status Reporting Overview Block Diagram

The status reporting structure consists of the registers shown in this figure.

The following table lists the bit definitions for each bit in the status reporting data structure.

Table 1-6. Status Reporting Bit Definition (1 of 3)

Bit Description Definition

PON Power On Indicates power is turned on.

1-21

Introduction

Status Reporting

Table 1-6. Status Reporting Bit Definition (Continued) (2 of 3)

Bit Description Definition

URQ Not used. Permanently set to zero.

CME Command Error Indicates if the parser detected an error.

EXE Execution Error Indicates if a parameter was out of range or was

inconsistent with the current settings.

DDE Device Dependent Error Indicates if the device was unable to complete an

operation for device dependent reasons.

QYE Query Error Indicates if the protocol for queries has been violated.

RQL Request Control Indicates if the device is requesting control.

OPC Operation Complete Indicates if the device has completed all pending

operations.

OPER Operation Status

RQS Request Service Indicates that the device is requesting service.

MSS Master Summary Status Indicates if a device has a reason for requesting service.

ESB Event Status Bit Indicates if any of the enabled conditions in the Standard

MAV Message Available Indicates if there is a response in the output queue.

MSG Message Indicates if an advisory has been displayed.

USR User Event Register Indicates if any of the enabled conditions have occurred

TRG Trigger Indicates if a trigger has been received.

LCL Local Indicates if a remote-to-local transition occurs.

FAIL Fail Indicates the specified test has failed.

COMP Complete Indicates the specified test has completed.

LTEST Limit Test Indicates that one of the enabled conditions in the Limit

MTEST Mask Test Indicates that one of the enabled conditions in the Mask

Indicates if any of the enabled conditions in the Operation Status Register have occurred.

Event Status Register have occurred.

in the User Event Register.

Test Register has occurred.

1-22

Introduction

Status Reporting

Table 1-6. Status Reporting Bit Definition (Continued) (3 of 3)

Bit Description Definition

ACQ Acquisition Indicates that acquisition test has completed in the

Acquisition Register.

CLCK CloCk Indicates that one of the enabled conditions in the Clock

Recovery Register has occurred.

UNLK UNLoCKed Indicates that an unlocked or trigger loss condition has

occurred in the Clock Recovery Module.

LOCK LOCKed Indicates that a locked or trigger capture condition has

occurred in the Clock Recovery Module.

NSPR1 No Signal Present

Receiver 1

SPR1 Signal Present

Receiver 1

NSPR2 No Signal Present

Receiver 2

SPR2 Signal Present

Receiver 2

LOSS Time Reference Loss Indicates the Precision Timebase (provided by the

PTIME Precision Timebase Indicates that one of the enabled conditions in the

Indicates that the Clock Recovery Module has detected the loss of an optical signal on receiver one.

Indicates that the Clock Recovery Module has detected an optical signal on receiver one.

Indicates that the Clock Recovery Module has detected the loss of an optical signal on receiver two.

Indicates that the Clock Recovery Module has detected an optical signal on receiver two.

Agilent 86107A module) has detected a time reference loss due to a change in the reference clock signal.

Precision Timebase Register has occurred.

1-23

Introduction

Status Reporting

Figure 1-2. Status Reporting Data Structures

1-24

Introduction

Status Reporting

Status Reporting Data Structures (continued)

1-25

Introduction

Status Reporting

Status Byte Register

The Status Byte Register is the summary-level register in the status reporting structure. It contains summary bits that monitor activity in the other status registers and queues. The Status Byte Register is a live register. That is, its summary bits are set and cleared by the presence and absence of a summary bit from other event registers or queues.

If the Status Byte Register is to be used with the Service Request Enable Register to set bit 6 (RQS/MSS) and to generate an SRQ, at least one of the summary bits must be enabled, then set. Also, event bits in all other status registers must be specifically enabled to generate the summary bit that sets the associated summary bit in the Status Byte Register.

The Status Byte Register can be read using either the *STB? common command query or the GPIB serial poll command. Both commands return the decimal-weighted sum of all set bits in the register. The difference between the two methods is that the serial poll command reads bit 6 as the Request Service (RQS) bit and clears the bit which clears the SRQ interrupt. The *STB? query reads bit 6 as the Master Summary Status (MSS) and does not clear the bit or have any affect on the SRQ interrupt. The value returned is the total bit weights of all of the bits that are set at the present time.

The use of bit 6 can be confusing. This bit was defined to cover all possible computer interfaces, including a computer that could not do a serial poll. The important point to remember is that, if you are using an SRQ interrupt to an external computer, the serial poll command clears bit 6. Clearing bit 6 allows the analyzer to generate another SRQ interrupt when another enabled event occurs.

The only other bit in the Status Byte Register affected by the *STB? query is the Message Available bit (bit 4). If there are no other messages in the Output Queue, bit 4 (MAV) can be cleared as a result of reading the response to the *STB? query.

If bit 4 (weight = 16) and bit 5 (weight = 32) are set, a program would print the sum of the two weights. Since these bits were not enabled to generate an SRQ, bit 6 (weight =

64) is not set.

Example 1

This HP BASIC example uses the *STB? query to read the contents of the analyzer’s Status Byte Register when none of the register's summary bits are enabled to generate an SRQ interrupt.

10 OUTPUT 707;":SYSTEM:HEADER OFF;*STB?"!Turn headers off 20 ENTER 707;Result!Place result in a numeric variable 30 PRINT Result!Print the result 40 End

The next program prints 132 and clears bit 6 (RQS) of the Status Byte Register. The difference in the decimal value between this example and the previous one is the value of bit 6 (weight = 64). Bit 6 is set when the first enabled summary bit is set, and is cleared when the Status Byte Register is read by the serial poll command.

1-26

+ 388 hidden pages

Agilent 86100A Programmer’s Guide

Specifications and Main Features

Frequently Asked Questions

User Manual