Response Messages; Sending A Response Message; Multiple Response Messages; Response Message Terminator (Rmt) - Keithley 2500 User Manual

13-16 Remote Operations

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 2500 is 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 2500 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 fol-
lowing 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 2500 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. Send the appropriate query command(s) in a program message.
2. Address the Model 2500 to talk.
Rule 2. The complete response message must be received by the computer before another
program message can be sent to the Model 2500.
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