Comtrol C53 - Manual (Page 7)

Reference Section 7
Reference Section
RS-232 Pinouts
The following depicts the RS-232 interface with the RJ45 connector.
Note: The DTR and DSR pins have been shorted. This releases the users from
the hardware flow control wiring problems. Therefore, only two types of
RS-232 cable wiring examples are listed in the following.
C52/C53 RJ45
Connector Pinouts
RS-232 Signals
1 DCD Always On
2 DTR
3 CTS
4 GND
5 RxD
6 TxD
7 GND
8 RTS
9 DSR
10 ------