Using the Modbus Plus Ports
870 USE 101 10 V.2 187
Cluster Mode Cabling Schemes
Introduction In cluster mode, Momentum I/O devices may be placed in small groups, c onnec ted
by much shorter lengths of cable than in standard Modbus Plus cabling schemes.
You may use clusters and standard single nodes in the same network.
Length of
Network The maximum length of cable from one end of the network to the other is 1500 ft.
(450 m) if no repeaters are used.
You can use up to three Modicon RR85 Repeaters to extend the cable to up to
6000 ft. (1800 m). Each repeater allows you to extend the cable 1500 ft. (450 m).
Number of
Devices in
Network
The maximum number of devices in a network is 64:
lIf you use only Momentum products, you may use up to 64 devices on one
cable segment without a repeater.
lIf you use a mixture of devices, you may use up to 32 devices on one cable
section. You must use a repeater to connect to anoth er cabl e sect ion. You may
use up to three repeaters and four cable sections in all.
Clusters in a
Network The maximum number of clusters in a network is 8. The maximum number of
devices in a cluster is 8. Only Momentum devices may be used in the cluster.
Continued on next page
Description Part Number
Modicon RR85 Repeater NW-RR85-000