Command Separators And Terminators - Agilent Technologies N8900 series Operating Manual

The command syntax shows most commands (and some parameters) as a mixture of upper- and lower-case letters.
The upper-case letters indicate the abbreviated spelling for the command. For shorter program lines, you can send the
abbreviated form. For better program readability, you can send the long form.
In the above examples, OUTP and OUTPUT are both acceptable forms. You can use upper- or lower-case letters. There-
fore, OUTPUT, outp, and Outp are all acceptable. Other forms such as OUT, are not valid and will generate an error.
Queries
Following a keyword with a question mark ( ? ) turns it into a query (Example: VOLTage?, VOLTage:TRIGgered?). If a
query contains parameters, place the query indicator at the end of the last keyword, before the parameters. Insert a
space between the query indicator and the first parameter.
You can query the programmed value of most parameters. For example, you can query the voltage setting by sending:
VOLTage?
You can also query the minimum or maximum allowable voltage settings as follows:
VOLTage? MIN
VOLTage? MAX
You must read back all the results of a query before sending another command to the instrument. Otherwise, a Query
Interrupted error will occur and the unreturned data will be lost.

Command Separators and Terminators

Separators
Colons ( : ) separate keyword levels. Blank spaces must be used to separate command parameters from their cor-
responding keyword. Note the space between STATe and the *RST parameter.
OUTPut:PON:STATe RST
Semicolons ( ; ) separate commands within the same subsystem. This lets you send several subsystem commands
within the same message string. For example, sending the following command string:
OUTPut:STATe ON;PON:STATe RST
is the same as sending the following commands:
OUTPut ON
OUTPut:PON:STATe RST
Note that the semicolon follows the implied path of the hierarchical tree structure. In the above example, the optional
:STATe keyword must follow the OUTput keyword to place the command parser at the second level in the hierarchy.
This allows the use of the PON keyword after the semicolon, since PON is a second-level keyword.
You can also combine commands of different subsystems within the same message string. In this case, you must use a
colon to return the command parser to the root level in order to access another subsystem. For example, you could
clear the output protection and check the status of the Operation Condition register in one message by using a root spe-
cifier as follows:
Agilent N8900 Series Operating and Service Guide
Introduction to the SCPI Language
73