Schneider Electric Processor Adapter - Manual (Page 185)

Using the Modbus Plus Ports
870 USE 101 10 V.2 185
Standard Cabling Schemes
Introduction In a standard Modbus Plus cabling scheme, each peer device connects via a drop
cable to a tap along a trunk cable.
Length 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).
Distance
Between Nodes Nodes must be separated by at least 10 ft. of cable. This requirement is more than
satisfied by standard drop cables:
Number of
Devices The maximum number of devices in a network is 64:
l
If you use only Momentum products, you may use up to 64 devices on one
cable section without a repeater.
l If 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 another cable section. You may
use up to three repeaters and four cable sections in all.
Termination You must terminate both ends of the network. If your network consists of two or
more sections separated by a repeater, each section must be terminated at both
ends.
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Description Part Number
Modicon RR85 Repeater NW-RR85-000
Description Part Number
Modbus Plus Drop Cable, 2.4 m / 8 ft. 990 NAD 211 10
Modbus Plus Drop Cable 6 m / 20 ft. 990 NAD 211 30