Connecting A Unitronics Plc To The Gw-Bac1 Via Modbus Rs-485; Figure 2: Power And Rs-485 Connections - Unitronics GW-BAC1 User Manual

Unitronics's BACnet Gateway User Guide
2.2

Connecting a Unitronics PLC to the GW-BAC1 via Modbus RS-485

GW-BAC1 6 Pin Phoenix connector for RS-485 Device

The 6 pin Phoenix connector is the same for GW-BAC1.

Pins 1 through 3 are for Modbus RS-485 devices.
o
The RS-485 GND (Pin 3) is not typically connected.

Pins 4 through 6 are for power. Do not connect power (wait until Section 3.4).
Device Pins
Pin RS-485 +
Pin RS-485 -
Pin GND
Power In (+)
Power In (-)
Frame Ground
Unitronics
GW-BAC1 Pin # Pin assignment
Pin 1 RS-485 +
Pin 2 RS-485 -
Pin 3 RS-485 GND
Pin 4
Pin 5
Pin 6 FRAME GND

Figure 2: Power and RS-485 Connections

V +
V -
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