39
Pin
Signal Description
1
DCD
2
TD
3
RD
4
DTR
5
GND
6
DSR
7
RTS
8
CTS
9
Contact Closure
RS-232 Pinout:
The diagram below shows the pin assignments for the female RS-232 connector on the DSP-3 Processors featured in the
215PCM.
*Note!
Pin 9 is used for contact closure input. This pin is not normally used by
RS-232 devices. Some laptop and desktop computer COM ports have been
observed to “pull” pin 9 to ground; this will cause unexpected behavior of the
contact closure function if pin 9 is not disconnected on the PC end of the cable.
If this behavior is observed, make sure that pin 9 is disconnected on the PC end
of the cable.
APPENDIX- RS-232 Pinout and Pin #9 Usage Note
