Command And Query Structure - Tektronix TDS7000 Series Programmer's Manual

Command and Query Structure

Commands consist of set commands and query commands (usually called commands and queries).
Commands modify instrument settings or tell the instrument to perform a specific action. Queries cause
the instrument to return data and status information.
Most commands have both a set form and a query form. The query form of the command differs from the
set form by its question mark on the end. For example, the set command ACQuire:MODe has a query
form ACQuire:MODe?. Not all commands have both a set and a query form. Some commands have set
only and some have query only.
Messages
A command message is a command or query name followed by any information the instrument needs to
execute the command or query. Command messages may contain five element types, defined in the
following table.
Command and Message Elements
Symbol Meaning
<Header> This is the basic command name. If the
header ends with a question mark, the
command is a query. The header may begin
with a colon (:) character. If the command is
concatenated with other commands, the
beginning colon is required. Never use the
beginning colon with command headers
beginning with a star (*).
<Mnemonic> This is a header subfunction. Some
command headers have only one mnemonic.
If a command header has multiple
mnemonics, a colon (:) character always
separates them from each other.
<Argument> This is a quantity, quality, restrictijon, or limit
associated with the header. Some
commands have no arguments while others
have multiple arguments. A <space>
separates arguments from the header. A
<comma> separates arguments from each
other.
<Comma A single comma is used between arguments
of multiple-argument commands. Optionally,
there may be white space characters before
and after the comma.
<Space> A white space character is used between a
command header and the related argument.
Optionally, a white space may consist of
multiple white space characters.
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