Specifications

20 PCL-741 User's Manual
The maximum length of a RS-232 cable is 100 ft. If you need to
connect over longer distances7 (longer than 100 h), please use
current-loop mode to match this requirement.
current Loop Signal Wiring
For Current loop interfacing, the wiring is based on one-to-one
principle and the connections are as follows:
PCL-741: De-9 malePC or Terminal
Pin Signal Pin Signal
1 TxD- 4 RxD
2 TxD+ 3 RxD+
3 RxD+ 2 TxD+
4 RxD- 1 TxD
RS-232/Current loop Pin Assignments
The two diagrams below show the pin assignments for the DB-9
connectors in both RS-232 and current-loop modes: