Schneider Electric Processor Adapter - Manual (Page 182)

Using the Modbus Plus Ports
182 870 USE 101 10 V.2
Modbus Plus Features for Momentum
Introduction When a Modbus Plus network is constructed entirely of Momentum components, it
may take advantage of two new features:
l cluster mode, which allows small groups of devices to be linked by short
lengths of cable;
l
supporting up to 64 nodes on a single section of cable.
Cluster Mode A cluster may consist of up to eight Momentum devices. A network may contain up
to eight clusters.
The cable between devices in a cluster may be 10 in to 3 ft. The cable between
clusters or between a cluster and the trunk must be at least 10 ft.
The maximum length of the network continues to be 1500 ft. The maximum number
of devices in a network continues to be 64.
64 Nodes When a Modbus Plus network consists entirely of Momentum devices, then a
single section of cable may support 64 nodes instead of the standard 32 nodes.
Example: If a single SA85 is added to a network of Momentum modules, the
network is no longer Momentum only, but a mixture of devices. Each cable section
must be limited to 32 nodes. Cable sections must be connected by a repeater.
Note: Only Momentum devices are allowed in a cluster.