Compac CNG Service Manual page 106

C4000 Microprocessor Board
RS485 Forecourt Wiring
C4000 Power Supply
C4000 IS Cable for RS485 Forecourt
Compac Industries Ltd.
Electrical Drawings and Component Details
The following changes are made to standard Compac C4000 wiring to allow
the use of RS485 communication with other devices.
An RS485 Board is fitted inside the Power supply flame proof box.
Connect the RS485 cable to the terminals on J12 as follows:
TXDP to RS485A
DTRP to RS485B
GND to GND
The IS cable pinouts will need to be changed to match the wiring detailed
below.
Page 106 www.compacngv.com