User Manual

Remote operation
Sending and re
ceiving commands
There are many ways in which to send commands to the PA3000, but there are
some common rules for all methods:
All instructions should be terminated with a line feed (ASCII 10) character.
All returned information will be terminated by a line feed (ASCII 10)
character.
Only one instruction can be sent a t a time. For example, :SEL:VLT;:SEL:AMP
is not a valid command.
For all commands that configure the unit, allow 0.5 seconds between each
command or use flow control to wait until the next command is sent.
The running of autozero, which happens every minute, results in no new
results for approximately one second. For this reason autozero can be disabled.
NOTE. When using communications through the Ethernet interface on the power
analyz
er, all communications will be responded to with a line feed character, such
as, ASCII LF(0x0A). In the examples below the line feed character is represented
by “[LF]”.
Tip. If using Visual Studio or LabVIEW, use the Flush, In-buffer command to
quickly remove the carriage return from the input buffer. This can be set up as a
discipline in the software to occur after every read and write command sent.
Example 1. Send a query to the power analyzer to determine the status of the
sh
unt. The power analyzer will respond with a LF added to the end of the string;
USER: “:SHU?”
Power analyzer: “0[LF]”
The power analyzer responds as normal with a LF character added to the end
of the string.
Example 2. User sends a command to the power analyzer to disable blanking and
the power analyzer responds with a LF character;
USER: “:SHU:INT”
Power analyzer: “[LF]”
The power analyzer responds with a LF character.
Using all other communication methods, the power analyzer does not reply with a
LF to every communication.
96 PA3000 Power Analyzer User Manual