5
◆
Connect the shields to an earth ground (DO NOT use a chassis ground) only at
one end of the segment; tape back the shield ground at the other end.
Wiring Notes
Use approved shielded cable and the following principles when connecting a
controller to a network:
◆
Connect no more than 124 Tier 2 KMC addressable controllers or devices to
the RS-485 network.
◆
Connect the nodes of the network in a daisy-chain arrangement. This means:
Connect the
A
terminal in parallel with all other
A
terminals.
Connect the
B
terminal in parallel with all other
B
terminals.
◆
Connect the shields of the cable together at each controller.
◆
Connect the shields to an earth ground at only one end of the segment; tape
back the shield ground at the other end.
◆
Use a KMD–5575 repeater between every 32 Tier 2 controllers or if the cable
length of the Tier 2 network exceeds 4000 feet (1220 meters). Use no more
than seven repeaters per network.
◆
Place a KMD–5567 surge suppressor in the cable where it exits a building.
Refer to Illustration 3 for an example of typical RS-485 connections.
KMD-5831 PLC-28 Direct Digital Controller Installation & Operation Guide
Installation
Illustration 3. Typical RS-485 Wiring Configuration
KMC Controller
Connections
Wiring
Shield
Wiring
Shield
Wiring
Shield
OR
