Comtrol UP DeviceMaster Installation - Manual (Page 50)

50 - Connecting Serial Devices Hardware Installation and Configuration Guide: 2000451 Rev. J
Connecting Serial Devices
Serial Terminal (8)
Null-Modem Cables
(RS-232) An RS-232 null-modem
cable is required for
connecting DTE devices.
RS-232 CD DSR RI DTR TxD RTS RxD CTS
RS-422/RS-485
Full-Duplex
N/A N/A N/A N/A TxD- TxD+ RxD- RxD+
RS-485 Half-
Duplex
N/A N/A N/A N/A TRxD- TRxD+ N/A N/A
† RS-232 ground must be connected to the appropriate signal ground
terminal.
† Wire gauge: AWG 12-22
Signal
Ground
Not connected
Positive† Return†
5-30VDC
Signal
Ground†
Chassis
Ground†
RS-232: Connecting the Ground
RS-232 Null-Modem Cable
CD DSR RI DTR RTS TxD RxD CTS
DCD DTR RI DSR CTS RxD TxD RTS
1 4 9 6 8 3 7
8 20 22 6 5 3 2 4
DB9
DB25
2