Siemens SIRIUS 3RW5 Equipment Manual page 64

Connecting
5.2 Fieldbus
5.2.2 3RW5 Modbus RTU communication module
5.2.2.1 Connecting the bus connection cable
Requirements
● Mounted 3RW5 communication module
● Correctly stripped bus connection cable for Modbus RTU (Page 41)
● Cable tie
● Jumper (optional)
Note
Malfunctions caused by EMC interference
The purpose of shielding cables is to attenuate (dampen) magnetic, electrical or
electromagnetic interference fields. Connect the cable shield of the fieldbus cable to system
ground with low impedance so that interference currents on the cable shield can be
conducted to ground.
Generally follow the instructions in the EMC Guide (http://www.siemens.com/emc-guideline)
and implement the measures stated in it for shielding the cables and for connecting the
shield.
General structure and design
Half duplex (RS 485), twisted-pair operation with multiple nodes:
LT
64
Line Termination
SIRIUS 3RW5 Modbus communication module
Equipment Manual, 03/2020, A5E43676481002A/RS-AC/003