36
C35-FC
16.2. Termination jumper
Position of the termination jumper is shown in the fi gure below. The termination jumper
should be connected on the fi rst and last device of the data bus segment. When the jumper is
connected, termination is enabled. A 120Ω resistor is connected between RS-485 nodes. When
the jumper is removed, the termination of the cable is disabled.
16. BACnet MS/TP network recommendations
16.1. Wiring and topology
BACnet wiring requirements
•
Use
Shielded Twisted Pair cable (0.2 mm2).
•
Maximum cable length for a data bus segment must not exceed 1200 m.
•
Only a daisy-chained data bus topology (as shown in drawing) is acceptable.
•
Connect cable shields together. Connect cable shield to the Protective Earth (PE) at one
point only.
•
Connect termination jumper on the fi rst and last device on the data bus (see below).
•
Maintain same polarity between devices on a single power supply.