Series 2230G Triple-Channel Power Supplies User's Manual
Section 4: Introduction to SCPI
2230G-900-01 Rev. A / June 2018
4-5
Observe the following precautions with queries:
•
Set up the proper number of variables for the returned data. For example, if you are reading back
a measurement array, you must dimension the array according to the number of measurements
that you have placed in the measurement buffer.
•
Read back all the results of a query before sending another command to the power supply. If you
send another command before the results of a query have been returned, an error message,
Query Interrupted
is generated and the unreturned data is lost.
Message unit separator
When two or more message units are combined into a compound message, separate the units with a
semicolon (;), for example:
STATus:OPERation?; QUEStionable?
Root specifier
When it precedes the first header of a message unit, the colon becomes the root specifier, as shown
in the following figure. It tells the command parser that this is the root or the top node of the command
tree.
Figure 16: SCPI message structure