HP 54601 Manual

Programmer’s Guide
Publication number 54600-97017
July1996 (pdf version Nov 1998)
This guide contains programming information for the following
oscilloscope models:
HP 54600
HP 54601
HP 54602
HP 54603
HP 54610
HP 54615
HP 54616
For Safetyinformation, Warranties,and Regulatory
information, see the pages behind the Index.
©Copyright Hewlett-Packard Company 1995-1996
All RightsReserved
HP 54600-Series Oscilloscopes

Programming the Oscilloscope
When you attach an interface module to the rear of the HP 54600-
Series Oscilloscopes, the oscilloscope becomes programmable. That is,
you can hook a controller (such as a PC or workstation) to the
oscilloscope, and write programs on that controller to automate
oscilloscope setup and data capture. Both HP-IB (also known as
GP-IB, IEEE-488) and RS-232-C interfaces are available.
The following figure shows the basic structure of every program you
will write for the oscilloscope.
Initialize
To ensure consistent, repeatable performance, you need to start the
program, controller, and oscilloscope in a known state. Without
correct initialization, your program may run correctly in one instance
and not in another. This might be due to changes made in
configuration by previous program runs or from the front panel of the
oscilloscope.
•Program initialization defines and initializes variables, allocates
memory, or tests system configuration.
•Controller initialization ensures that the interface to the
oscilloscope (either HP-IB or RS-232) is properly setup and ready
for data transfer.
•Oscilloscope initialization sets the channel, trigger, timebase, and
acquisition subsystems for the desired measurement.
ii

Capture
Once you initialize the oscilloscope, you can begin capturing data for
measurement. Remember that while the oscilloscope is responding to
commands from the controller, it is not performing acquisitions. Also,
when you change the oscilloscope configuration, any data already
captured is most likely invalid.
To collect data, you use the DIGITIZE command. This command
clears the waveform buffers and starts the acquisition process.
Acquisition continues until the criteria, such as number of averages,
completion criteria, and number of points is satisfied. Once the
criteria is satisfied, the acquisition process is stopped. The acquired
data is displayed by the oscilloscope, and the captured data can be
measured, stored in memory in the oscilloscope, or transferred to the
controller for further analysis. Any additional commands sent while
DIGITIZE is working are buffered until DIGITIZE is complete.
You could also start the oscilloscope running, then use a wait loop in
your program to ensure that the oscilloscope has completed at least
one acquisition before you make a measurement. This is not
recommended, because the needed length of the wait loop may vary,
causing your program to fail. DIGITIZE, on the other hand, ensures
that data capture is complete. Also, DIGITIZE, when complete, stops
the acquisition process, so that all measurements are on displayed
data, not a constantly changing data set.
Analyze
After the oscilloscope has completed an acquisition, you can find out
more about the data, either by using the oscilloscope measurements
or by transferring the data to the controller for manipulation by your
program. Built-in measurements include IEEE standard parametric
measurements (such as Vpp, frequency, pulse width) or the
positioning and reading of voltage and time markers.
Using the WAVEFORM commands, you can transfer the data to your
controller for special analysis, if desired.
iii

In This Book
The HP 54600-Series Oscilloscopes Programmer’s Guide is your
introduction to programming the HP 54600-Series Oscilloscopes using an
instrument controller. This book, with the online HP 54600-Series
Oscilloscopes Programmer’s Reference, provides a comprehensive
description of the oscilloscope’s programmatic interface. The Programmer’s
Reference is supplied as a Microsoft Windows Help file on a 3.5" diskette.
To program the HP 54600-Series Oscilloscope, you need an interface module,
such as the HP 54650A or 54651A. You also need an instrument controller
that supports either the IEEE-488 or RS-232-C interface standards, and a
programming language capable of communicating with these interfaces. You
can also use the HP 54655A/56A Test Automation Module and the
HP 54658A/59B Measurement/Storage Module.
Chapter 1 gives a general overview of oscilloscope programming.
Chapter 2 shows a simple program, explains its operation, and discusses
considerations for data types.
Chapter 3 discusses the general considerations for programming the
instrument over an HP-IB interface.
Chapter 4 discusses the general considerations for programming the
instrument over an RS-232-C interface.
Chapter 5 describes conventions used in representing syntax of commands
throughout this book and in the online HP 54600-Series Oscilloscopes
Programmer’s Reference, and gives an overview of the command set.
Chapter 6 discusses the oscilloscope status registers and how to use them in
your programs.
Chapter 7 tells how to install the HP 54600-Series Oscilloscopes
Programmer’s Reference online help file in Microsoft Windows, and explains
help file navigation.
Chapter 8 lists all the commands and queries available for programming the
oscilloscope.
For information on oscilloscope operation, see the HP 54600-Series
Oscilloscopes User and Service Guide. For information on interface
configuration, see the documentation for the oscilloscope and the interface
card used in your controller (for example, the HP 82341A interface for IBM
PC-compatible computers).
iv

ProgrammingGetting Started
2
Programmingover HP-IB
3
Programmingover RS-232-C
4
Index
Programmingand
DocumentationConventions
5
Status Reporting
6
Installing and Using the
Programmer’s Reference
7
Programmer’s Quick Reference
8
Introduction to Programming
1
v

vi

Contents
1 Introduction to Programming
Talking to the Instrument 1–3
Program Message Syntax 1–4
Combining Commands from the Same Subsystem 1–7
Duplicate Mnemonics 1–7
Query Command 1–8
Program Header Options 1–9
Program Data Syntax Rules 1–10
Program Message Terminator 1–12
Selecting Multiple Subsystems 1–12
2 Programming Getting Started
Initialization 2–3
Autoscale 2–4
Setting Up the Instrument 2–4
Example Program 2–5
Using the DIGitize Command 2–6
Receiving Information from the Instrument 2–8
String Variables 2–9
Numeric Variables 2–10
Definite-Length Block Response Data 2–11
Multiple Queries 2–12
Instrument Status 2–12
3 Programming over HP-IB
Interface Capabilities 3–3
Command and data concepts 3–3
Addressing 3–4
Communicating over the bus 3–5
Lockout 3–6
Bus Commands 3–6
4 Programming over RS-232-C
Interface Operation 4–3
Cables 4–3
Contents–1

Minimum three-wire interface with software protocol 4–4
Extended interface with hardware handshake 4–5
Configuring the Interface 4–7
Interface Capabilities 4–8
Communicating over the RS-232-C bus 4–9
Lockout Command 4–10
5 Programming and Documentation Conventions
Command Set Organization 5–3
The Command Tree 5–6
Truncation Rules 5–10
Infinity Representation 5–11
Sequential and Overlapped Commands 5–11
Response Generation 5–11
Notation Conventions and Definitions 5–12
Program Examples 5–13
6 Status Reporting
Serial Poll 6–6
7 Installing and Using the Programmer’s Reference
To install the help file under Microsoft Windows 7–3
To use the help text and example program files 7–4
To get updated help and program files via the Internet 7–5
To start the help file 7–6
To navigate through the help file 7–7
8 Programmer’s Quick Reference
Conventions 8–3
Suffix Multipliers 8–3
Commands and Queries 8–4
Index
Contents
Contents–2

1
Introduction to Programming

Introduction to Programming
Chapters 1 and 2 introduce the basics for remote programming of an
oscilloscope. The programming instructions in this manual conform to
the IEEE 488.2 Standard Digital Interface for Programmable
Instrumentation. The programming instructions provide the means of
remote control.
To program the HP 54600-series oscilloscope you must add either an
HP-IB (for example, HP 54650A) or RS-232-C (for example,
HP 54651A) interface to the rear panel.
You can perform the following basic operations with a controller and
an oscilloscope:
•Set up the instrument.
•Make measurements.
•Get data (waveform, measurements, configuration) from the
oscilloscope.
•Send information (pixel image, configurations) to the oscilloscope.
Other tasks are accomplished by combining these basic functions.
Languages for Program Examples
The programming examplesfor individual commands in this manual are written
in HP BASIC, C, or SICL C.
1–2

Talking to the Instrument
Computers acting as controllers communicate with the instrument by
sending and receiving messages over a remote interface. Instructions for
programming normally appear as ASCII character strings embedded inside
the output statements of a “host” language available on your controller. The
input statements of the host language are used to read in responses from the
oscilloscope.
For example, HP BASIC uses the OUTPUT statement for sending commands
and queries. After a query is sent, the response is usually read in using the
ENTER statement.
Messages are placed on the bus using an output command and passing the
device address, program message, and terminator. Passing the device address
ensures that the program message is sent to the correct interface and
instrument.
The following HP BASIC statement sends a command which sets the
bandwidth limit of channel 1 on:
OUTPUT < device address > ;":CHANNEL1:BWLIMIT ON"<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.
Introduction to Programming
Talking to the Instrument
1–3

Program Message Syntax
To program the instrument remotely, you must understand the command
format and structure expected by the instrument. The IEEE 488.2 syntax
rules govern how individual elements such as headers, separators, program
data, and terminators may be grouped together to form complete
instructions. Syntax definitions are also given to show how query responses
are formatted. The figure below shows the main syntactical parts of a typical
program statement.
Program Message Syntax
Output Command
The output command is entirely dependent on the programming language.
Throughout this manual, HP BASIC is used in most 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 in
order to convert the examples. The instructions listed in this manual are
always shown between quotation marks in the example programs.
Device Address
The location where the device address must be specified is also dependent
on the programming language you are using. In some languages, this may be
specified outside the output command. In HP BASIC, this is always specified
after the keyword OUTPUT. The examples in this manual assume the
oscilloscope is at device address 707. When writing programs, the address
varies according to how the bus is configured.
Figure 1–1
Introduction to Programming
Program Message Syntax
1–4

Instructions
Instructions (both commands and queries) normally appear as a string
embedded in a statement of your host language, such as 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 learnstring.
There are only a few instructions which 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 provide additional information needed to clarify
the meaning of the instruction.
Instruction Header
The instruction header is one or more mnemonics separated by colons (:)
that represent the operation to be performed by the instrument. The
command tree in chapter 5 illustrates how all the mnemonics can be joined
together to form a complete header (see chapter 5, “Programming and
Documentation Conventions”).
The example in figure 1 is a command. Queries are indicated 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 have included
the question mark. The command and query forms of an instruction usually
have different program data. Many queries do not use any program data.
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 are used to clarify the meaning of the command or query. They
provide necessary 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, as well as the values they accept. The section
“Program Data Syntax Rules” in this chapter has all of the general rules about
acceptable values.
When there is more than one data parameter, they are separated by
commas (,). Spaces can be added around the commas to improve readability.
Introduction to Programming
Program Message Syntax
1–5

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 instrument. The syntax is:
<program mnemonic><terminator>
Simple command headers must occur at the beginning of a program message;
if not, they must be preceded by a colon.
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:
<program mnemonic><separator><program data><terminator>
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 :CHANNEL1:BWLIMIT ON)
Common Command Header Common command headers control IEEE
488.2 functions within the instrument (such as clear status). Their
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.
Introduction to Programming
Program Message Syntax
1–6

Combining Commands from the Same Subsystem
To execute more than one function within the same subsystem a semi-colon
(;) is used to separate the functions:
:<subsystem>:<function><separator><data>;
<function><separator><data><terminator>
(For example :CHANNEL1:COUPLING DC;BWLIMIT ON)
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:
:CHANNEL1:RANGE .4
sets the vertical range of channel 1 to 0.4 volts full scale.
:TIMEBASE:RANGE 1
sets the horizontal time base to 1 second full scale.
CHANNEL1 and TIMEBASE are subsystem selectors and determine which
range is being modified.
Introduction to Programming
Combining Commands from the Same Subsystem
1–7

Query Command
Command headers immediately followed by a question mark (?) are queries.
After receiving a query, the instrument interrogates the requested function
and places the answer in its output queue. The answer remains in the output
queue until it is read or another command is issued. When read, the answer is
transmitted across the bus to the designated listener (typically a controller).
For example, the query :TIMEBASE:RANGE? places the current time base
setting in the output queue. In HP BASIC, the controller input statement:
ENTER < device address > ;Range
passes the value across the bus to the controller and places it in the variable
Range.
Query commands are used to find out how the instrument is currently
configured. They are also used to get results of measurements made by the
instrument. For example, the command :MEASURE:RISETIME? instructs the
instrument to measure the rise time of your waveform and places 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
that query 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.
Read the QueryResult First
Sending another command or query before readingthe result of a query causes
the output bufferto be cleared and the current response to be lost.This also
generates a query interrupted error in the error queue.
Introduction to Programming
Query Command
1–8

Program Header Options
Program headers can be sent using any combination of uppercase or
lowercase ASCII characters. Instrument responses, however, are always
returned in uppercase.
Program command and query headers may be sent in either long form
(complete spelling), short form (abbreviated spelling), or any combination of
long form and short form.
TIMEBASE:DELAY 1US - long form
TIM:DEL 1US - short form
Programs written in long form are easily read and are almost
self-documenting. The short form syntax conserves the amount of controller
memory needed for program storage and reduces the amount of I/O activity.
CommandSyntaxProgramming Rules
The rulesfor the short form syntax are shown in chapter 5, “Programming and
Documentation Conventions.”
Introduction to Programming
Program Header Options
1–9

Program Data Syntax Rules
Program data is used to convey a variety of types of parameter information
related to the command header. At least one space must separate the
command header or query header from the program data.
<program mnemonic><separator><data><terminator>
When a program mnemonic or query has multiple program data a comma
separates sequential program data.
<program mnemonic><separator><data>,<data><terminator>
For example, :MEASURE:TVOLT 1.0V,2 has two program data: 1.0V and 2.
There are two main types of program data which are used in commands:
character and numeric program data.
Character Program Data
Character program data is used to convey parameter information as alpha or
alphanumeric strings. For example, the :TIMEBASE:MODE command can be
set to normal, delayed, XY, or ROLL. The character program data in this case
may be NORMAL, DELAYED, XY, or ROLL. The command
:TIMEBASE:MODE DELAYED sets the time base mode to delayed.
The available mnemonics for character program data are always included
with the instruction’s syntax definition. When sending commands, either the
long form or short form (if one exists) may be used. Upper-case and
lower-case letters may be mixed freely. When receiving query responses,
upper-case letters are used exclusively.
Numeric Program Data
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 have the option of using exponential notation
or using 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, that means
that the number should be whole. Any fractional part would be ignored,
truncating the number. Numeric data parameters which accept fractional
values are called real numbers.
Introduction to Programming
Program Data Syntax Rules
1–10

All numbers are expected to be strings of ASCII characters. Thus, when
sending the number 9, you would send a byte representing the ASCII code for
the character “9” (which is 57). A three-digit number like 102 would take up
three bytes (ASCII codes 49, 48, and 50). This is taken care of automatically
when you include the entire instruction in a string.
Embedded Strings
Embedded strings contain groups of alphanumeric characters which are
treated as a unit of data by the oscilloscope. For example, the line of text
written to the advisory line of the instrument with the :SYSTEM:DSP
command:
:SYSTEM:DSP"This is a message."
Embedded strings may be delimited with either single (’) or double (")
quotes. These strings are case-sensitive and spaces act as legal characters
just like any other character.
Introduction to Programming
Program Data Syntax Rules
1–11

Program Message Terminator
The program instructions within a data message are executed after the
program message terminator is received. The terminator may be either an NL
(New Line) character, an EOI (End-Or-Identify) asserted in the HP-IB
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).
New Line Terminator Functions
The NL (New Line) terminatorhas the same function as an EOS (End Of String)
and EOT(End Of Text) terminator.
Selecting Multiple Subsystems
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 enables you to enter a new subsystem. For
example:
<program mnemonic><data>;:<program mnemonic><data><terminator>
:CHANNEL1:RANGE 0.4;:TIMEBASE:RANGE 1
Combining Compound and SimpleCommands
Multiple commands may be anycombination of compound andsimple
commands.
Introduction to Programming
Program Message Terminator
1–12