Cutler-Hammer D320 PLC, User Manual

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Chapter 4: Installation and Wiring
43
PLC Communications Wiring
Connecting the PLC to a PC
The D320 PLC communication ports (COM1, COM2) support both RS-232C and RS-485
communications.
The diagram below shows local communications connections for the D320 PLC.
D320 CPU Module Communication Specification
Connection
Specification RS-485 RS-232C Remarks
Transfer distance (max.) 4000 ft (1.2 km) 50 ft (15 m)
Transfer speed 38400, 19200, 9600
Dip switch setting
COM1: 9600, 19200
COM2: 9600, 19200, 38400
Protocol Half duplex asynchronous polling
Parity No parity
Stop bit 1 Stop bit
Cable type Twisted pair cable Use Shielded cable.
Program Loaders D320PGM500
GPC5, WinGPC,
D320PGM500
D320 CPU module
IBM PC compatible type
D320CBL20
D320CBL50
RS-232/485 communication cable
CPU internal switch
1 2 3 Baud Rate
Off - - 9600 bps, COM1
On - - 19200 bps, COM1
- Off Off 9600 bps, COM2
- On Off 19200 bps, COM2
- Off On 38400 bps, COM2
- On Off Reserved
1, 2, 3 switch
(select communication speed
9600 to 38400 bps)
On, On: RS485
Termination Resistors
Connected, COM2
Off, Off: RS485
Termination Resistors
Disconnected,
COM2
Not used
DIP1
ON
6
5
4
3
2
1