Biddle Modbus Manual page 9

M
ODBUS MANUAL
Manual for software version U3.0 – 01 (22-06-2017)
2.3.2 Connecting the unit to Modbus
1. Lay a cable between the Modbus system and the unit.
In the case of BACnet: Lay the cable between the gate-
way and the unit.
2. Attach the cable to the unit, in accordance with the wiring
diagram supplied:
In the case of BACnet: Use the circuit diagram below.
For SR:
- Connect the cable to terminal X74 on the upper side
of the unit.
For IndAC and NOZ
2
- Feed the cable into the electronics housing.
- Connect the cable to terminal X380 1 of the unit's
control circuit board.
Note:
n
For a more reliable signal, it is possible to connect a
120 Ohm resistor. For this purpose, place a bridge
between positions 1 and B of terminal X382 on the
control circuit board in the unit.
Connecting multiple units to Modbus
If you also want to be able to read out the local registers of
each unit individually, the Modbus connection must be con-
nected in series.
For SR:
1. Lay a cable between the units.
2. Connect the cable on both units to terminal X74 (on the
upper side of the unit).
3. Repeat steps 1 and 2 for each unit that is to be connected
in series.
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NSTALLATION
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