HP Instrument BASIC User’s Handbook
Supplement
HP 8712ET/ES and HP 8714ET/ES
RF Network Analyzers
HP Part No. 08714-90019
Printed in USA
Print Date: October 1998
© Copyright 1998 Hewlett-Packard Company
Notice
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.
Firmware Revision
This manual documents analyzers with firmware revisions E.06.00 and
above.
ii HP IBASIC Supplement
Contents
1. Introduction
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Overview of HP Instrument BASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Using HP Instrument BASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Allocating Internal Memory for IBASIC Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Typographical Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
2. Recording Programs
Keystroke Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
What Is Keystroke Recording?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
IBASIC Programs and the Input Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
What's in a Recorded Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
The OUTPUT Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
The ASSIGN Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
SCPI Mnemonics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
How Recording Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-8
Operations that Do Not Record. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Front Panel Operations without Mnemonics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
HP Instrument BASIC Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Operations Requiring Additional Programming. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Mnemonics with No Corresponding Front Panel Operation . . . . . . . . . . . . . . . . . . 2-12
Avoiding Recording Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Use Instrument Preset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Specifically Select Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Use HP-IB Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
3. Running, Pausing, and Stopping Programs
Starting Programs Automatically. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Running and Continuing a Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Pausing and Continuing a Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Using LOCAL LOCKOUT 8 to Disable the Pause Key . . . . . . . . . . . . . . . . . . . . . . . 3-7
Stopping a Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
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Contents
4. Saving and Recalling Programs
Selecting a Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Saving a Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
AUTOST Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
Recalling a Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
CAT to a String Array Exception. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
5. Developing Programs
External Editors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
HP BASIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
ASCII Word Processors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Programming Editors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4
Editing Your Program Using Edit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
The IBASIC Editor Softkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6
Recording into an Existing Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7
Editing with an External Keyboard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8
Entering Program Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11
Editing from the Front Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-12
Removing Program Text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-14
Renumbering, Copying, Moving, and Indenting Lines . . . . . . . . . . . . . . . . . . . . . . .5-16
Using IBASIC Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17
Using UTILITIES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-20
6. Debugging Programs
Setting Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3
Examining Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4
Examining Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Examining Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Displaying the Last Error Encountered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6
7. Graphics and Display Techniques
Display Partitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
Using the Display Partitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
Allocating Display Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
De-Allocating Display Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
Operation with No Display Partition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
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Contents
Displaying Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7
Getting Text to the Screen Quickly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Pop-Up Message Windows and Custom Annotations. . . . . . . . . . . . . . . . . . . . . . . . . 7-9
Graphics Initialization and Scaling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Using Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
Drawing Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Graphics Exceptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
Labeling with Different Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
SCPI Graphics Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
For More Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17
8. Interfacing with External Devices
Communication with Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
HP-IB Device Selectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Moving Data through the HP-IB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
General Structure of the HP-IB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Using the Serial and Parallel Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Using the Analyzer Ports in IBASIC Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
General Bus Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9
REMOTE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
LOCAL LOCKOUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10
LOCAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
TRIGGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
CLEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
ABORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
HP-IB Service Requests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
Passing and Regaining Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17
The IBASIC HP-IB Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
The External Bus and the Internal Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Service Request Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
IBASIC as the Active Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-19
Passing Active Control to the Instrument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-20
IBASIC as a Non-Active Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21
Interfacing with an External Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-22
Synchronizing IBASIC with an External Controller . . . . . . . . . . . . . . . . . . . . . . . . 8-23
Transferring Data between Programs Using OUTPUT and ENTER Statements . 8-25
iii
Contents
Transferring Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-27
IBASIC Communication across the LAN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-29
9. Using Subprograms
User-Created Subprograms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-2
Built-In High-Speed Subprograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3
Avoiding Multiple Loads of Subprograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-9
10. IBASIC Keyword Summary
Keywords in Alphabetic Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-3
Keywords in Category Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-14
iv
1 Introduction
1-1
Introduction
Introduction
Introduction
This manual describes how to create and use HP Instrument BASIC
(IBASIC) software in the analyzer. It demonstrates how to use IBASIC's
programming, editing and debugging features. It also describes how to
save and recall programs and how certain instrument-specific IBASIC
features are implemented in the analyzer. The reader should be familiar
with the operation of the analyzer and BASIC before programming the
analyzer.Related information can be found in the following references
that were shipped with your analyzer:
• The Programmer’s Guide, a companion to this book, provides
general-purpose programming information. The Programmer’s Guide
describes all valid instrument commands.
• The User’s Guide provides information on making measurements
with the analyzer.
• The HP Instrument BASIC User’s Handbook provides information on
HP Instrument BASIC (IBASIC) .
• The Example Programs Disk — DOS format: part number
08714-10003, is included with the analyzer. This disk provides copies
of all of the example programs in the Example Programs Guide.
• Additional information on HP BASIC programming is available in the
manual set for the BASIC revision being used. For example: BASIC
7.0 Programming Techniques and BASIC 7.0 Language Reference.
Other information that may be helpful can be found in the following
reference materials:
• The Tutorial Description of the Hewlett-Packard Interface Bus (HP
literature no. 5021-1927) provides information on using the HP-IB.
Contact the nearest HP sales office for ordering information. A list of HP
sales and service offices can be found in the “Specifications and
Characteristics” chapter of the User’s Guide.
1-2 HP IBASIC Supplement
Overview of HP Instrument BASIC
HP-IB
Overview of HP Instrument BASIC
HP Instrument BASIC (IBASIC) can be used for a wide range of
applications, from simple recording and playback of measurement
sequences to remote control of other instruments. IBASIC is a complete
language with over 200 keywords.
IBASIC is a complete system controller residing inside your analyzer. It
communicates with the analyzer via HP-IB commands over an internal
interface bus (select code 8). It can also communicate with other
instruments, computers, and peripherals using the external HP-IB
interface (select code 7) or the serial (select code 9) or parallel (select code
15) I/O ports.
NOTE The analyzer can also be controlled by an external controller.
It has a factory default external HP-IB address of 16. When using
IBASIC to control other instruments, no other device should use the
same address.The external HP-IB address can be changed using either
the front panel keys under the , menu, or
the SCPI mnemonic SYST:COMM:GPIB:ADDR.
SYSTEM OPTIONS
Introduction
HP IBASIC Supplement 1-3
Introduction
Using HP Instrument BASIC
Using HP Instrument BASIC
Y ou need not be proficient in a programming language to successfully use
IBASIC. In keystroke recording mode, IBASIC automatically builds an
executable program by capturing measurement sequences as they are
performed. With little or no editing of these program lines, you can
immediately put your program to work to control and automate your
analyzer.
The IBASIC language is a subset of the HP BASIC language. In fact,
IBASIC programs can be run on any HP BASIC workstation with very
few changes. When an external PC keyboard (with a DIN connector) is
connected to the analyzer, the IBASIC user interface emulates the user
interface of the HP BASIC. The PC keyboard can be used for command
entry, editing and program inputs.
You can use IBASIC to do the following:
• create on screen graphics
• control other instruments and peripherals
• create interactive prompts
• simplify keystrokes with the key
• create programs by recording keystrokes
• run applications
IBASIC also works in conjunction with an external controller which can
download and run programs, query variables and respond to service
requests (SRQs).
1-4 HP IBASIC Supplement
BEGIN
Allocating Internal Memory for IBASIC Use
Select Disk
Configure VOL_RAM
Modify Size
Modify Size
Allocating Internal Memory for IBASIC
Use
Your analyzer contains a volatile RAM disk that is configured for use
with IBASIC. The default condition set at the factory allocates most of
this disk's memory for IBASIC use. To see what the current allocations
are for this disk, press
display that shows total memory available, and how the memory is
currently allocated.
To change the allocations, use the softkey. The number
you enter with the softkey, is the percentage of memory
that will be used for normal disk functions (such as storing instrument
states). The remainder will be allocated for use with IBASIC.
NOTE Cycle power after changing the allocations.
You must cycle the power on the analyzer for new allocations to take
effect.
SAVE RECALL
. A message will appear on the analyzer's
Introduction
HP IBASIC Supplement 1-5
Introduction
Softkey
Softkey ON off
Softkey 1
Softkey 2
Typographical Conventions
Typographical Conventions
The following conventions are used in this manual when referring to
various parts of the HP Instrument BASIC and analyzer operation
environments:
HARDKEY
HARDKEY
<element> Angle brackets are used to signify a syntax element in a statement.
computer font User input and computer output is shown with a mono-spaced font.
The name of a hardkey on the front panel of the analyzer. This
notation is also used to represent keys on an external keyboard
connected to the analyzer's DIN interface.
The label of a softkey.
Upper case selection in a softkey indicates the state after the
softkey is pressed.
A series of hardkeys and softkeys represents the path to a given
softkey or menu.
1-6 HP IBASIC Supplement
2 Recording Programs
2-1
Recording Programs
Keystroke recording, described in this chapter, is ideal for creating
simple programs or measurement sequences for instrument control.
Other methods of program development may be used to supplement
keystroke recording and create more sophisticated programs. If a
program requires data processing, decision making, operator input, or a
display of graphical diagrams, other program development methods are
needed. These methods are covered in Chapter 5, “Developing
Programs.”
IBASIC programs for the analyzer can be created and edited using the
following methods:
• the front panel keys and knob
• an external keyboard (Option 1CL)
• an HP controller running HP BASIC
• a workstation or PC using a text editor or programming editor
2-2 HP IBASIC Supplement
Recording Programs
IBASIC
Key Record on OFF
IBASIC
Key Record on OFF
Run
IBASIC
Keystroke Recording
Keystroke Recording
Keystroke recording is the easiest way to create IBASIC programs. It
requires only a couple of steps to set up and run, and very little
programming knowledge is required.
What Is Keystroke Recording?
Keystroke recording is a way to automatically create IBASIC
measurement sequence programs. To record a program, press the
following keys:
•
SYSTEM OPTIONS
• Normal key sequences for the measurement
• to
SYSTEM OPTIONS
terminate recording
The resulting program can then be run by pressing in the
SYSTEM OPTIONS
menu.
Keystroke recording works by finding the SCPI mnemonic that fits each
operation performed by the instrument; then it builds a program line to
perform that operation when the recorded program is executed. All
program lines built by keystroke recording are entered into the
analyzer's program buffer. If the buffer contains no existing lines, a
complete executable program will be created. If there is a program in the
buffer when recording is turned on, the recorded statements are inserted
into the existing program. Refer to Chapter 5, “Developing Programs,”
for a description of how to record into existing programs.
HP IBASIC Supplement 2-3
Recording Programs
Keystroke Recording
IBASIC Programs and the Input Buffer
Recorded programs send commands to the instrument, and use the same
set of commands used by external controllers for remote operation of the
instrument.
These commands are stored in an input buffer by the instrument. An
IBASIC program generally outputs the commands much faster than the
instrument can execute them. This often causes the program to complete
while the instrument is still executing commands in the input buffer . The
instrument continues processing these commands until the buffer is
empty.
This may have some side-effects if you are not aware of this interaction.
For example, it may not be immediately obvious that the program has
actually finished, since the instrument is still functioning “remotely.”
This could cause confusion if you try to pause and continue a program
that has actually ended.
You can clear the buffer from within your program by inserting the
statement CLEAR 8 at the beginning of your program (see Chapter 5 for
information on editing programs).
Another side-effect of the speed with which the analyzer processes
commands is that it is possible for a command to execute before a
previous command has completed execution. The most common example
of this is a data query that executes before a measurement sweep is
complete. This interaction can lead to erroneous data being collected. F or
more information on synchronizing the execution of commands, refer to
“Synchronizing the Analyzer and a Controller” in the Programmer's
Guide.
2-4 HP IBASIC Supplement
Recording Programs
What's in a Recorded Program
What's in a Recorded Program
A program created using keystroke recording is composed of three
fundamental IBASIC statements: ASSIGN, OUTPUT and END. The
following simple program demonstrates these statements:
1 ASSIGN @Rfna TO 800
2 OUTPUT @Rfna;”SOUR1:POW -10 dBm”
10 END
The ASSIGN and END statements are automatically created when
keystroke recording is used to create a new program (as opposed to
modifying an existing one).
There will only be one ASSIGN statement at the beginning of a program
and one END statement at the end, but in a typical program there will be
many OUTPUT statements. Since the OUTPUT statement does the actual
work of controlling the analyzer, let's take a closer look at how it is used.
NOTE Each analyzer model requires a unique ASSIGN statement.
The ASSIGN statement, which is automatically created, will vary
depending on the model of the analyzer:
HP 8712ES/ET ASSIGN @Hp8712 To 800
HP 8714ES/ET ASSIGN @Hp8714 TO 800
HP IBASIC Supplement 2-5
Recording Programs
What's in a Recorded Program
The OUTPUT Statement
The IBASIC statement
OUTPUT <destination>;<data>
tells the internal computer to send some information(data) to a device
at a specific address(destination). The destination can be a device
selector number (example: OUTPUT 800), or a name representing a
number, called a path name (example: OUTPUT@Rfna). In recorded
IBASIC programs, the data are strings containing commands for the
instrument (mnemonics).
The following represents a typical OUTPUT command from a recording
session:
OUTPUT @Rfna;”SOUR1:POW -10 dBm”
Notice that the OUTPUT command is followed by a name representing a
device selector (@Rfna), followed by a semicolon and the data
(SOUR1:POW -10 dBm).
The ASSIGN Statement
The destination in an OUTPUT statement specifies the address of the
device. In recorded programs this address is represented by the I/O path
name @Rfna. The following line appears in all recorded programs before
any OUTPUT statements:
ASSIGN @Rfna to 800
The ASSIGN statement allows you to substitute an I/O path name (a
variable preceded by the @ symbol) for a device selector number.
Therefore, after the above ASSIGN statement, the program line
OUTPUT @Rfna;”SOUR1:POW -10 dBm”
is equivalent to
OUTPUT 800;”SOUR1:POW -10 dBm”
The device selector 800 specifies the host instrument as the destination
of any data sent by the OUTPUT command. The program communicates
with the analyzer via select code 8, the internal HP-IB interface, which is
2-6 HP IBASIC Supplement
used only for communication between IBASIC programs and the
analyzer. The analyzer will respond to any address on the internal
interface from 800 to 899 (800 is typically used).
SCPI Mnemonics
The data sent to the analyzer by the OUTPUT command is called a SCPI
(Standard Commands for Programmable Instruments) mnemonic and is
found in quotes following the device selector path name and semicolon.
See Figure 2-1.
Figure 2-1 Example IBASIC OUTPUT Command Syntax
OUTPUT @Rfna;"SOUR1:POW -10 dBm”
Recording Programs
What's in a Recorded Program
IBASIC command
IBASIC variable: Holds
device selector path name
(analyzer address)
SCPI is a standard instrument control programming language that
provides commands that are common from one product to another, thus
reducing the number of device specific commands. It uses easy-to-learn,
self-explanatory syntax that provides flexibility for both novice and
expert programmers.
The SCPI mnemonic codes used by IBASIC are the same ones used to
control the instrument remotely via an external computer. External
computers communicate with the analyzer over the external HP-IB bus
while IBASIC programs communicate with it over the internal bus. In
our example, the mnemonic “SOUR1:POW -10 dBm” tells the
instrument to set the source power to −10 dBm.
For more information on HP-IB interfacing using IBASIC, refer to
Chapter 8, “Interfacing with External Devices.” The SCPI mnemonics for
the analyzer are documented in the Programmer's Guide.
Delimiter: Separates
IBASIC command from
SCPI mnemonic
SCPI mnemonic
(command)
HP IBASIC Supplement 2-7
Recording Programs
Level
2
Enter
How Recording Works
How Recording Works
Keystroke recording works by recording the functional operation of the
instrument, not by recording every keystroke. A sequence of SCPI
mnemonics forms the recorded sequence of operations.
As you press a sequence of keys to perform an operation, SCPI
mnemonics for that operation are generated and recorded. The operation
may take one keystroke or several keystrokes, but the mnemonic is not
generated until the operation is complete.
In other words, it is the functional operation of the instrument that is
recorded as a mnemonic. The separate, individual keystrokes to perform
that operation are not recorded.
For example , recording the simple key sequence:
1 0
mnemonic that is generated after the keystroke sequence is completed:
“SOUR1:POW -10dBm”
This mnemonic is then automatically formed into the command
OUTPUT @Rfna;”SOUR1:POW -10 dBm”
and is inserted into the program.
If you accidentally press an incorrect key in a sequence, it may not show
up in the recorded program. Also, you cannot exactly mimic keystrokes to
leave the instrument in a specific front panel state, unless this state
appears as a natural consequence of a completed operation.
As shown in the above example, pressing the hardkey in a
recording session has the effect of bringing up the menu, but
does not, by itself, generate a program line. You could not, therefore,
leave the instrument with the menu displayed.
requires six keystrokes and produces a single
POWER
POWER
POWER
POWER
−
2-8 HP IBASIC Supplement
Recording Programs
IBASIC
Operations that Do Not Record
Operations that Do Not Record
Although keystroke recording works automatically in most situations,
some operations cannot be captured or can only be partially captured
using this method. This is true for one of the following reasons:
• There is no corresponding SCPI mnemonic for the front panel
keystrokes (such as transitional key sequences).
• The keystrokes are IBASIC front panel operations (such as some of
the softkey operations found under the
menu).
• The operation requires additional programming steps (such as
passing control of the HP-IB to the instrument for hardcopy output).
• The HP-IB operation has no front panel equivalent (such as HP-IB
query commands or data transfer).
• The keystrokes are service menu keys (in general).
SYSTEM OPTIONS
NOTE Do not recall programs in keystroke record mode.
This will overwrite previously recorded program steps.
Front Panel Operations without Mnemonics
The following descriptions indicate areas of front panel operation which
have no corresponding SCPI mnemonics:
• Most operations on the front panel requiring numeric entry allow use
of the knob to increment or decrement the current value. This will not
record as a program line. Always use the numeric keypad or step keys
to enter any value if you want the operation to be recorded.
• During a measurement sequence, it may take several key presses to
cause an operation that will generate a mnemonic. The transitional
sequences between actual instrument events are not recordable. For
example, pressing the key displays the scale numeric entry,
but nothing is recorded until you enter a value for the scale
parameter.
HP IBASIC Supplement 2-9
SCALE
Recording Programs
IBASIC
Run
Continue
Edit
Programs
Operations that Do Not Record
• Any default states which you set up prior to recording or which you
encounter while recording (and consequently do not select) are not
recorded.
• Use of step keys is not recommended because the results may depend
on the function's step size, which may change as other parameters
change.
NOTE Instrument states that are not specifically selected or changed are not
recorded.
Since these default states are not recorded, you must either actively
select them to generate a program statement, or make sure the
instrument is in exactly the same state when the program is run as when
it was recorded. This is discussed further in “A voiding Recording Errors”
later in this chapter.
HP Instrument BASIC Operations
Some softkeys under the menu cannot
be recorded. Operations on programs, such as , ,
and , do not record. You can,
SAVE RECALL
however, record display partitions and all other save and recall
operations not having to do with IBASIC programs.
Although IBASIC operations cannot be recorded, many do have
corresponding SCPI mnemonics that allow an external controller to
control and communicate with internal IBASIC programs. For more
information, refer to Chapter 8, “Interfacing with External Devices.”
SYSTEM OPTIONS
Operations Requiring Additional Programming
Some operations that work well when performed manually from the
front panel require special attention when used in a program. This is due
to two interactions: synchronization and active control.
2-10 HP IBASIC Supplement
Recording Programs
Start
Abort
Operations that Do Not Record
Synchronization
Often, one event must be completed before another can occur. Suppose
you want your program to perform a limit test on data, but only after a
sweep has been completed. You can record the command to perform the
limit test by pressing key sequences. However, to detect when the
instrument has completed a sweep, you must edit the program and
include a routine that waits for a status register to indicate the end of
the sweep.
CAUTION Synchronization is required only with overlapped commands.
Overlapped commands, such as the command to trigger a sweep, don't
hold off the processing of subsequent commands, and are not necessarily
completed when the next command begins. The analyzer adds a “wait”
command (*WAI) when an overlapped command is created using
keystroke recording. *WAI delays processing of subsequent commands
until previous commands have been parsed. *WAI does not insure
previous commands have completed. For more information on
synchronization, see “Synchronizing the Analyzer and a Controller” in
the Programmer's Guide.
Active Control of the HP-IB Interface
Some operations require the analyzer to be the active controller on the
external HP-IB bus. The analyzer must be the System Controller (or
active control must be passed to it from an external controller). When an
IBASIC program begins running, control of the external interface is
automatically passed to the program, so active control must be passed
back to the analyzer before these operations can be performed.
These operations include all of the following actions when they are
directed to HP-IB devices.
•
HARDCOPY
•
HARDCOPY
NOTE Active control of the HP-IB interface is only a problem if that bus is being
used. Hardcopy output to devices on the serial or parallel ports do not
require control of the HP-IB.
HP IBASIC Supplement 2-11
Recording Programs
Operations that Do Not Record
The example program “PASSCTRL” in theExample Programs Guide and
on the Example Programs Disk illustrates these concepts.
You can use keystroke recording for any of these operations but you will
not be able to successfully run the program that is generated. You will
need to enter the program lines necessary to first pass control to the
analyzer and then wait for control to be passed back to the program.
See “Passing and Regaining Control” in Chapter 8 for an example of
passing control to the analyzer.
Mnemonics with No Corresponding Front
Panel Operation
Several of the analyzer SCPI mnemonics for the instrument perform
operations that are not available from the front panel and cannot be
recorded. These include operations such as querying instrument status,
transferring data over HP-IB, setting and clearing status registers, and
general HP-IB housekeeping.
These operations are useful for the more advanced HP-IB programmer
using IBASIC. Because they fall outside the direct operating realm of the
analyzer, they cannot be recorded. They can be added to a recorded
program using the built-in editor or another editing environment. See
your analyzer's Programmer's Guide for a complete description of the
analyzer's HP-IB command set. See also “Built-In High Speed
Subprograms” in Chapter 9.
2-12 HP IBASIC Supplement
Avoiding Recording Errors
Log Mag
Trigger
Hold
Continuous
Use Instrument Preset
Recording Programs
Avoiding Recording Errors
In most cases, the key/operation should be the first keystroke
recorded. This sets the instrument to its default state and avoids the risk
of creating a program that depends on prior instrument settings.
You can include the command to perform a preset in your program by
pressing immediately after turning recording on. This
inserts the following line prior to all other OUTPUT statements in your
program:
OUTPUT @Rfna;”SYST:PRES;*WAI”
See your analyzer's User's Guide to determine the specific preset state
for your particular analyzer.
PRESET
PRESET
Specifically Select Parameters
If you do not want to preset the instrument before running a recorded
program (for example, you may be recording a section of a larger
measurement sequence), be sure to specifically activate every
instrument setting that you will need in your automated sequence. For
example, if you want the data format to be Log Mag, press
and then , even though Log Mag is already the default
setting. This will generate a program line to specifically set the data
format to Log Mag.
In some cases you may have to select another setting first and then
re-select the original setting in order to generate the correct program
line. F or example, if you w ant to generate a program line to set the sweep
trigger to Continuous, and you discover that it is already set to
Continuous when you start recording, press
first—then press . You can easily remove unwanted
program lines generated by this procedure in the editor.
MENU
FORMAT
HP IBASIC Supplement 2-13
Recording Programs
HP-IB
HP-IB Echo on OFF
Avoiding Recording Errors
NOTE Do not rely on the step keys or the front panel knob to set parameters.
Use of step keys is not recommended because the results may depend on
the function's step size, which may change as other parameters change.
Use HP-IB Echo
HP-IB echo is a useful analyzer feature that allows you to view the SCPI
mnemonic or mnemonics corresponding to any operation executed from
the front panel. To turn on HP-IB echo, press
and . After doing this, you will see a
mnemonic appear in a dialogue box on the screen as you complete any
key sequence that has a matching SCPI mnemonic.
This mnemonic is used in your recorded program during a recording
session.
Using HP-IB echo, you can preview the SCPI mnemonic commands that
will be stored in your program before you actually record them. While
this is not essential, it can be very useful when you are in doubt as to
what a particular key sequence will record, or precisely when a key
sequence corresponding to a mnemonic is completed.
SYSTEM OPTIONS
2-14 HP IBASIC Supplement
3 Running, P ausing, and Stopping
Programs
3-1
Running, Pausing, and Stopping Programs
This chapter describes how to start, stop, and pause a program from the
front panel. Automatic execution of a program is described.
IBASIC programs can also be remotely controlled via SCPI commands
over the HP-IB. For information on running, pausing and stopping
programs using an external controller, see Chapter 8, “Interfacing with
External Devices.”
3-2 HP IBASIC Supplement
Running, Pausing, and Stopping Programs
Starting Programs Automatically
Starting Programs Automatically
When the analyzer is powered up, it automatically searches for a
program named AUTOST or AUTOST.BAS. When an AUTOST program is
found, it is automatically loaded and executed. The analyzer searches in
the following order:
• internal non-volatile RAM disk
• internal floppy disk drive
The AUTOST program can be used for anything from configuring the
analyzer for specific measurements, much like an internal instrument
state Save/Recall register, to diagramming measurement setups using
graphics commands, as in a guided measurement sequence.
Refer to Chapter 4, “Saving and Recalling Programs,” for information on
using the analyzer to name programs before they are saved.
HP IBASIC Supplement 3-3
Running, Pausing, and Stopping Programs
Run
IBASIC
Run
Enter
IBASIC
IBASIC
Running and Continuing a Program
Running and Continuing a Program
To run an IBASIC program that is already in the analyzer program
buffer, press the softkey in the
menu. The RUN command can also be executed from an external
keyboard in three ways:
SYSTEM OPTIONS
• Press the function key that corresponds to the softkey
(see note below).
• Type RUN on a command line and press . A command line is
always available when an IBASIC display is partitioned. (See
Chapter 5, “Developing Programs,” for information about display
partitions.) You can also activate a command line from an external
keyboard with no IBASIC displays partitioned by pressing the
key on your external keyboard.
• Press the function key when the command line is available.
NOTE The keyboard function keys duplicate softkey actions.
When an external keyboard is connected, the function keys through
always represent the analyzer's eight softkeys. The analyzer's
F8
hardkeys are each represented by a combination of or and
one of the function keys. Refer to your analyzer's User's Guide for more
information on the external keyboard interface. The
SYSTEM OPTIONS
keyboard using + (for ) and (for
). A keyboard template showing which keys to press for specific
analyzer functions is supplied with your analyzer (HP part number
08712-80028).
Ctrl F3 SYSTEM OPTIONS F1
F1
F9
Shift Ctrl
menu can be accessed from an external
ESC
F1
3-4 HP IBASIC Supplement
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