Response Message Terminator (Rmt) - Keithley 2520 User Manual

10-16 Remote Operations

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 2520 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 2520.
RS-232 interface operation
NOTE
Sending and receiving data
The RS-232 interface transfers data using 8 data bits, 1 stop bit, and no parity. Make sure
the device you connect to the Model 2520 also uses these settings.
You can break data transmissions by sending a ^C (decimal 3) or ^X (decimal 18) charac-
ter string to the instrument, or by sending an RS-232 break condition (holding the transmit
line low for >11 bits). This clears any pending operation, discards any pending output, and
returns a "DCL."
Baud rate
The baud rate is the rate at which the Model 2520 and the programming terminal commu-
nicate. Choose one these available rates:
•
•
•
Send the appropriate query command(s) in a program message.
Address the Model 2520 to talk.
The programmable aspects of RS-232 operation (baud rate, data bits, parity,
and terminator) are configured from the COMMUNICATIONS SETUP menu
accessed with the COMM key.
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Model 2520 User's Manual