Keithley 2750, Руководство пользователя

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Model 2750 Multimeter/Switch System User’s Manual Remote Operations 10-17
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 “Multiple
command messages,” page 10-15 ), the multiple response messages for all the queries are
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. Send the appropriate query command(s) in a program message.
2. Address the Model 2750 to talk.
Rule 2.
The complete response message must be received by the computer before another
program message can be sent to the Model 2750.
2750-900-01.book Page 17 Wednesday, August 3, 2011 7:56 AM