Connecting The Rs-485 - Bosch F.01U.252.722 User Manual

NurseCall Relay Unit
3.2.7

Connecting the RS-485

One NurseCall Main Unit and up to 32 NurseCall Relay Units can be connected to an RS-485
bus. Please contact a specialist for a correct installation.

CAUTION!
Do not use a star connection for the RS-485 network!
Incorrect connection:
Correct connection:
NOTICE!
The NurseCall Main or Relay Units located at the two ends of the bus must be terminated with
a 100 Ohm resistor.
Bosch Security Systems
See Section A.5.4 RS-485 socket (unit rear), page 34 for connector wiring.
RS-485 bus (1 twisted pair cable)
100 Ω
Relay Unit n
Relay Unit 1
Relay Unit 2
Relay Unit 2
User Manual
Installation | en
Main Unit
Relay Unit n
100 Ω
Main Unit Relay Unit 1
F.01U.252.722 | V1 | 2011.12
17