janitza UMG 806, User Manual And Technical Data

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UMG 806 www.janitza.com
7.8.3 Bus structure (bus segment)
In a bus structure:
· Connect all devices in line.
· Each device has its own device address.
· You can integrate up to 32 devices (nodes).
Terminate the beginning and the end of your bus
segment with termination resistors (inside the de-
vices or with 120 Ω/0.25 W termination resistors).
· Use repeaters (signal amplifi ers) to connect bus
segments if there are more than 32 nodes.
· Devices with bus termination switched on must
be powered.
· It is recommended that the master be placed at
the end of a segment. If the master is replaced
with the bus termination switched on, the bus is
out of operation.
· The bus can become unstable if a slave with bus
termination switched on is replaced or is de-en-
ergized.
· Devices that are not involved in the bus termina-
tion can be replaced without the bus becoming
unstable.
Fig. Representation of a bus structure
Slave
Slave Slave Slave Repeater
Slave Slave Slave
Master
T
T
T
T
- Power supply necessary
T
- Bus terminator on
- e.g. UMG 605 Master
- e.g. UMG 806 Slave