MGE UPS Systems 250A - Manual (Page 15)

34020201EN/AB - Page 15
Q2
Q1
RS-232 RS-485
1
2
3
2. Installation
2.5 Communication connections
1. Connect the communication cable to the
RS232 or RS485 connector on the right-
hand door of the module.
2. Run the cable as shown in the figure
opposite.
3. Tie the cable down to the module frame.
Communication connector details
RS485 connector
2 wires
GND
Tx+
Tx-
Tx+ / Rx+
Tx- / Rx-
RS485 connector
4 wires
GND
Rx+
Rx-
Not used
Not used
Td (from the PMM
display)
Rd (to the PMM display)
GND
RS232 connector
RS-485 RS-232
1 2 3 4 5
6 7 8 9
5 4 3 2 1
Example of an RS485 2-wire
connection:
Example of an RS485 4-wire connection:
Master Slave Master or slave
5 4 3 2 1
Tx- / Rx- Tx+ / Rx+ GND 5 4 3 2 1
Rx- Rx+ GND Tx- Tx+ Rx- Rx+ GND Tx- Tx+
5 4 3 2 1