16
Serial Ports
Fieldbus (RS485)
Termination resistors
All units have to be connected in a single line bus
structure. One segment holds up to 32 units. Use
termination resistors on both ends of each segment.
Repeaters must be used to connect the segments if
more than 32 units or longer lines are needed.
Shield
Use shielded twisted pair cable for the RS485 bus.
To ensure sufficient shielding the cable shield con-
nection must be short and plane-style. Do not use
pigtail shield connection.
Cable type
Unitronic Li2YCY(TP)2x2x0,22 (Lapp Kabel)
Cable length
1200m at 38400 baud.
Termination resistor
Unit with RS485 port
Fig. Bus structure with termination on each end. Ter-
mination resistor unit with RS485 port
Installation
