Interfacing to a Serial Device
Appendix E
GPIB-232CT-A for MS-DOS/Windows E-2
© National Instruments Corp.
Table E-1. RS-232 Serial Port Signal Configuration
Pin
Number
Signal
Description
RS-232
Code
Function
2
RXD
(Receive
Data)
BB
This signal carries serial data from
the serial device to the
GPIB -232CT-A.
3
TXD
(Transmit
Data)
BA
This signal carries serial data from
the GPIB-232CT-A to the serial
device.
4
DTR (Data
Terminal
Ready)
CD
This signal is asserted by the
GPIB -232CT-A to s ignal that it has
been powered on and is ready to
operate.
5
GND
(Ground)
AB
This signal establishes a reference
point for all interface voltages.
7
RTS
(Request to
Send)
CA
This signal is driven by the
GPIB -232CT-A. When asserted, it
indicates that the GPIB-232CT-A is
ready to accept serial data. When
unasserted, it indicates that the
GPIB-232CT-A is no longer ready
to accept serial data because the
buffer is full.
8
CTS (Clear
to Send)
CB
This signal is sensed by the
GPIB -232CT-A. When asserted, it
indicates that the serial device is
ready to accept serial data. When
unasserted, it indicates that data
transmission should be disabled.
