Western Telematic APS-16 - Manual (Page 50)

A. RS232 Port Interface
DCD and DTR hardware lines function as follows:
1. When connected:
a) If either port is set for Modem Mode, the DTR output at either port reflects the DCD
input at the other end.
b) If neither port is set for Modem Mode, DTR output is held high (active).
2. When not connected:
a) If the port is set for Modem Mode, upon disconnect DTR output is pulsed for 0.5
seconds and then held high.
b) If the port is not set for Modem Mode, DTR output is controlled by the DTR Output
option (Parameters Menu, Option 74). Upon disconnect, Option 74 allows DTR
output to be held low, held high, or pulsed for 0.5 seconds and then held high.
Apx-1
Figure A.1: RS232 Port Interface