User`s guide

1-6

Introduction to Programming

Program Message Syntax

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:

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 CHANNEL1), white space is added to separate the data

from the header. The syntax is:

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>

(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.