Response Messages; Message Exchange Protocol - Keithley 2750 User Manual

Model 2750 Multimeter/Switch System User's Manual

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 2750 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 (see
command messages," page
sent to the computer when the Model 2750 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
Response message terminator (RMT)
Each response is terminated with an LF (line feed) and EOI (end or identify). The follow-
ing example shows how a multiple response message is terminated:
0; 1; 1; 0 <RMT>

Message exchange protocol

Two rules summarize the message exchange protocol:
Rule 1. You must always tell the Model 2750 what to send to the computer.
The following two steps must always be performed to send information from the instru-
ment to the computer:
1.
2.
Rule 2. The complete response message must be received by the computer before another
program message can be sent to the Model 2750.
10-15), the multiple response messages for all the queries are
Send the appropriate query command(s) in a program message.
Address the Model 2750 to talk.
Remote Operations 10-17
"Multiple