ABB FMBA-01 - Bus termination

Electrical installation
18
Bus termination
Bus termination is required to prevent signal reflections from the
bus cable ends. The FMBA-01 Modbus Adapter module is
equipped with internal bus termination, which is configurable with
jumper J1 pins. Termination should be activated on devices
located at bus ends and deactivated on other devices. See the
figure below.
RS-485 device
ON
RS-485 device
OFF
RS-485 device
ONOFF
Term. Term. Term. Term.
RS-485 bus termination
J1
Termination
activated
Termination
activated
Termination
deactivated
Termination
deactivated
J1J1 J1
RS-485 device