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Programming the Enhanced Monitor 45
Chapter 3
Chapter 3
Programming the Enhanced Monitor
This chapter explains how to program the enhanced monitor of the HP E8402A and
E8404A VXI mainframes including:
•
Complete C language program examples
•
Complete SCPI Command Reference
•
Complete IEEE 488.2 Common Command Reference
Understanding SCPI Commands
Commands are separated into two types: IEEE 488.2 Common Commands and SCPI
Commands.
Common
Command
Format
The IEEE 488.2 standard defines the Common commands that perform functions
like reset, self-test, status byte query, etc. Common commands are four or five
characters in length, always begin with the asterisk character (*), and may include
one or more parameters. The command keyword is separated from the first
parameter by a space character. Some examples of Common commands are shown
below:
*RST *ESR 32 *STB? *TST?
SCPI
Command
Format
The SCPI commands perform functions like setting parameters, making
measurements, and querying instrument states or retrieving data. A subsystem
command structure is a hierarchical structure that usually consists of a top level (or
root) command, one or more lower-level commands, and their parameters. The
following example shows part of a typical subsystem:
:DISPlay
[:WINDow]
<display window>
[:WINDow]?
:TEXT
[:DATA] <
string >
[:DATA]?
:DISPlay is the root command, [:WINDow] is a second-level command with
parameter.
Command
Separator
A colon (:) always separates one command from the next lower-level command as
shown in the example subsystem above.