janitza UMG 96RM-P - Interfaces and Communication; RS485 Interface

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UMG 96RM-P/-CBM
RS485 interface
The RS485 interface is designed with the UMG 96RM-
P/-CBM as a 2-pole plug contact and communicates
via the Modbus RTU protocol (also see programming
parameters).
Correct
Incorrect
Terminating resistors
The cable is terminated with resistors (120 ohm 1/4 W)
at the beginning and end of a segment.
The UMG 96RM-P/-CBM has no terminating resistors.
Terminal block in the switch cabinet.
Device with RS485 interface.
(without a terminating resistor)
Device with RS485 interface.
(with terminating resistor on the device)
RS485 interface,
2-pole plug contact
RS485 interface,
2-pole plug contact
with terminating resistor
(Item no. 52.00.008)
A
B
120 Ω
RS485 bus
A
B
RS485 bus