National Instruments GPIB-232CV, User Manual

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Interfacing to a Serial Device Appendix B
GPIB-232CV User Manual B-2 © National Instruments Corp.
Table B-1. RS-232 Serial Port Signals
RS-232
Name Pin Signal Name Function
AA 1 PG This line is connected to the chassis
(Protective ground of the GPIB-232CV. Since
Ground) the chassis ground is not connected
to earth ground, pin 1 should be
connected on both serial devices.
BA 2 TxD This line carries serial data from the
(Transmit Data) GPIB-232CV to the serial host.
BB 3 RxD This line carries serial data from the
(Receive Data) serial host to the GPIB-232CV.
CA 4 RTS This signal line is driven by the
(Request to GPIB-232CV and when asserted
Send) indicates that the GPIB-232CV is
ready to accept serial data. The
GPIB-232CV unasserts RTS when it
is no longer ready to accept serial
data because the buffer is full.
CB 5 CTS This signal line is asserted by the
(Clear to Send) serial host and sensed by the
GPIB-232CV. When asserted, it
indicates that the serial host is ready
to accept serial data. When
unasserted, it indicates that data
transmission should be disabled.
AB 7 SG This line establishes a reference
(Signal Ground) point for all interface voltages.
CD 20 DTR This signal line is asserted by the
(Data Ready) GPIB-232CV to signal that it has
been powered on and is ready to
operate.