Tektronix PWS4205, Programmer'S Manual

Page: 13 / 90

Command Syntax
You can control the power supply through the USB interface using commands
and queries.
This section describes the syntax these commands and queries use and the
conventions the power supply uses to process them. The commands and queries
themselves are listed by group and alphabetically. (See page 2-7,
Command
Groups .)
You transmit commands to the power supply using the enhanced American
Standard Code for Information Interchange (ASCII) character encoding.
Appendix
A contains a chart of the ASCII character set.
The Backus Naur Form (BNF) notation is used in this manual to describe
commands and queries. (See Table 2-1.)
Table 2-1: BNF notation
Symbol Meaning
< >
De fi ned element
::=
Is de fi ned as
| Exclusive OR
{ } Group; one element is required
[ ] Optional; can be omitted
. . .
Previous element(s) may be repeated
( ) Comment
Command and Query Structure
Commands consist of set commands and query commands (usually simply called
commands and queries). Commands change power supply settings or perform a
speci
fi c action. Queries cause the power supply to return data and information
about its status.
Most commands have both a set form and a query form. The query form of the
command is the same as the set form except that it ends with a question mark.
For example, the set command STATus:OPERation:ENAble has a query form
STATus:OPERation:ENAble?. Not all commands have both a set and a query
form; some commands are set only and some are query only.
A command message is a command or query name, followed by any information
the power supply needs to execute the command or query. Command messages
consist of
fi ve different element types. (See Table 2-3.)
PWS4205, PWS4305, PWS4323, PWS4602, and PWS4721 Power Supply Programmer Manual 2-1