Rockwell Automation 1747-L5xx SLC 500 Modular Hardware Style User Manual - Manual (Page 193)

Publication 1747-UM011G-EN-P - June 2008
Setting Up the DH-485 Network 193
Installing the DH-485
Network To install a DH-485 network, you will need tools to strip the shielded
cable and to attach the cable and terminators to the Isolated Link
Coupler.
Install the DH-485 network using the following tools (or equivalent).
DH-485 Communication Cable and Isolated Link Coupler
The link coupler provides a connection for each node. The isolated
link coupler electrically isolates the DH-485 communication interface
from the processor and peripheral connections. Electrical-optical
isolation is provided to 1500V.
The suggested DH-485 communication cable is Belden #3106A or
#9842 cable. The cable is jacketed and shielded with two twisted wire
pairs and a drain wire.
One pair provides a balanced signal line, and one wire of the other
pair is used for a common reference line between all nodes on the
network. The shield reduces the effect of electrostatic noise from the
industrial environment on the network communication.
Installing the DH-485 Communication Cable
The communication cable consists of a number of cable segments
daisy-chained together. The total length of the cable segments cannot
exceed 1219 m (4000 ft).
When cutting cable segments, make them long enough to route them
from one link coupler to the next with sufficient slack to prevent
Description Part Number Manufacturer
Shielded twisted pair cable Belden #3106A or #9842 Belden
Stripping tool 45-164 Ideal Industries
1/8 in. slotted screwdriver Not applicable Not applicable