Chapter 3
Local Command Set
3-4
ni.com
Command Response Format
Commands do not have program mode responses. They do not return a response to a port
configured for console mode response only, unless the GPIB-VXI/C detects an error
condition.
Console mode command responses are self-explanatory and are not described in this manual.
Query Response Format
Queries have both program and console mode responses. Program mode query responses are
fixed-field formatted, with commas delimiting the fields. For example, the list of logical
addresses returned by the
Laddrs?
query is returned as groups of three characters (to allow
the field to accommodate the valid range of 0 to 254) separated by commas. The values are
right-justified and padded with the ASCII space character (
) (20h). For example, Logical
Address 45 would be returned as (
45
). Unless otherwise noted, all returned values are
decimal.
Console mode query responses are self-explanatory and are not described in this manual.
The query response line termination sequence, shown in the query descriptions as <CRLF>,
indicates an ASCII 0Dh followed by 0Ah.
Error Reporting
Command syntax and execution errors are reported to the port where the command
originated. If the program response mode is enabled, the GPIB-VXI/C returns an error
message in the following format:
$ <error code>
<CRLF>
The distinguishing characteristic of a program mode error message is the leading dollar sign
character (
$
). A list of error code descriptions is given in Appendix E,
If the console response mode is enabled, the GPIB-VXI/C returns an error message in the
following format:
<error description>
<CRLF>
If both response modes are enabled, the program mode error message is returned first,
followed by the console mode message.
The Help Query
The
Help?
query is a quick online reference to the syntax and functionality of the
GPIB-VXI/C local command set.
