6
1MRS750532-MUM
Bus Connection Module
Technical Description
RER 103
2
Principle of operation
The RER 103 Bus Connection Module can be used in Loop and Star type bus
topologies. Also the line idle state of the module is selectable. It can be light on or
off. The selection of Loop/Star and light on/off is made by jumpers.
In the Loop topology the RER 103 module passes a message received from the fibre-
optic interface both to the fibre-optic transmitter and the RS-485 interface.
In the Star topology the module passes a message received from the fibre-optic
receiver only to the RS-485 interface.
A message received from the RS-485 interface is passed to the fibre-optic
transmitter in both bus topologies.
SPA bus communication is using Loop and light off modes, when the module
jumpers are in Loop and light off positions. LON
®
bus communication is using Star
and light off modes, when the module jumpers are in Star and light off positions.
IEC_103 bus communication is using Star and light on or off modes, when the
module jumpers are in Star and light on or off positions.
In LON
®
bus communication the RER 103 module supports collision detection. The
Service Pin is connected via the RS-485 interface to the Neuron
®
chip of the device
connected to the RER 103.
Fig. 2.-1 Rear side of the RER 103 module
Table 2.-1 Settings of the jumper
Topology
Light on/off
Protocol
Star
Off
LON or IEC 60870-5-103
Star
Light
IEC 60870-5-103
Loop
Off
SPA
Loop
Light
Not supported
