Keithley 2520, User Manual, Page: 154 / 329

Model 2520 User’s Manual Remote Operations 10-15
Using common and SCPI commands in the same message
Both common commands and SCPI commands can be used in the same message as long
as they are separated by semicolons (;). A common command can be executed at any com-
mand level and will not affect the path pointer. Example:
:stat:oper:enab <NRf>; *ESE <NRf>
Program message terminator (PMT)
Each program message must be terminated with an LF (line feed), EOI (end or identify),
or an LF+EOI. The bus will hang if your computer does not provide this termination. The
following example shows how a multiple command program message must be terminated:
:outp1 on <PMT>
Command execution rules
• Commands execute in the order that they are presented in the program message.
• An invalid command generates an error and, of course, is not executed.
• Valid commands that precede an invalid command in a multiple command program
message are executed.
• Valid commands that follow an invalid command in a multiple command program
message are ignored.
Response messages
A response message is the message sent by the instrument to the computer in response to a
query command program message.
Sending a response message
After sending a query command, the response message is placed in the Output Queue.
When the Model 2520 is then addressed to talk, the response message is sent from the
Output Queue to the computer.
Multiple response messages
If you send more than one query command in the same program message ( Multiple com-
mand messages ), the multiple response messages for all the queries are sent to the com-
puter when the Model 2520 is addressed to talk. The responses are sent in the order the
query commands were sent and are separated by semicolons (;). Items within the same
query are separated by commas (,). The following example shows the response message
for a program message that contains four single item query commands:
0; 1; 1; 0