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3.2
Connecting the R1 & R2 Ports
For the R1 Port only:
Switch between RS-485 and RS-232 by moving the number 4 DIP Switch left for RS-485 and right
for RS-232 (see images in
Section
).
The R2 Port is RS-485.
Connect to the 3-pin connector(s) as shown below.
3.2.1 Wiring
RS-485
RS-232
BMS
RS-485 Wiring
Gateway Pin
Assignment
BMS
RS-485 Wiring
Gateway Pin
Assignment
RS-485 +
TX +
RS-232 -
TX +
RS-485 -
RX -
RS-232 +
RX -
GND
GND
GND
GND
NOTE: Use standard grounding principles for GND.
3.2.2 Supported RS-485 Baud Rates by Protocol
The supported baud rates for either port is based on the protocol of the connected devices.
The following baud rates are supported for Modbus RTU:
2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200
The following baud rates are supported for BACnet MS/TP:
9600, 19200, 38400, 76800, 115200
10
EZ Gateway Modbus to BACnet Start-up Guide