Chapter 3
Operation of the GPIB-232CV-A
3-8
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Modes of Operation Within C Mode
Four different modes of operation are available within C mode to define
when the GPIB device is addressed to talk or listen. These modes are as
follows:
•
Timeout termination
•
<CR> termination
•
<LF> termination
•
No-swap
In every mode, the device is addressed to listen after the GPIB-232CV-A
becomes CIC, and all data received via the serial port is buffered and passed
along to the device. The four modes of operation define the point at which
the GPIB device is unaddressed to listen and addressed to talk so that data
can be sent from the device to the GPIB-232CV-A. You can select these
modes using SW1 switches 6 and 7.
Timeout Termination Mode
Timeout termination mode should be used for applications in which
bidirectional communication is required and neither a <CR> nor <LF>
character is used to signal the end of a command string to the GPIB device.
To select timeout termination mode, set SW1 switches 6 and 7 to OFF.
Figure 3-6 shows the cycle of events in timeout termination mode.
Figure 3-6.
Timeout Termination Mode Cycle
Receive Serial
Data
Serial Buffer Empty
and No Serial Data
Received for 300 msec
Serial
Device
Serial
Device
GPIB Device
Addressed
to Talk
GPIB Device
Addressed
to Listen
DATA
DATA
DATA
DATA
PO
WER
READ
Y
TALK LISTEN
B
USY
FULL
GPIB-232CV-A
FUSE
PO
WER
READ
Y
TALK LISTEN
B
USY
FULL
GPIB-232CV-A
FUSE