Access Modular Controller 2 Installing | en 23
Bosch Security Systems B.V.
Installation manual
2021-04 | V04 | IM
4.9 RS-485 host interface
The RS-485 host interface of the controller can be set for using a 2- or 4-wire connection. Up
to eight controllers can be used on one host bus.
Figure4.9: Configuration of a RS-485 host system
Position Description
1 Host
2 RS-485 bus
3 Access Modular Controller
The following conditions apply for a RS-485 bus system:
– A bus system consists of a bus line and/or one or more branch lines.
– Cable lengths exceeding 100m (300ft) must be installed as bus lines.
– Branch lines are branching connections from a bus line.
– Peripheral devices are controllers which are connected to the host computer.
– Maximum cable length of a bus line must not exceed 1200m (4000ft).
– The cable length of branch lines must not exceed 100m (330ft).
To use RS-485 mode at the controller, connect the data cables to the pluggable screw
connector of the RS-485 host interface.
Figure4.10: RS-485 host interface