The limitations for Modbus Plus Cluster Mode are:
- Cluster mode can only be used with the Momentum PRODUCTS.
- There can only be up to 8 clusters with up to 8 nodes per cluster (max. 64 nodes).
- Between each cluster you must have 10 feet of cable minimum.
- When the configuration has between 2 and 8 nodes in a cluster there is still a limitation of 8 clusters maximum.
If you have 3 clusters with 4 nodes and 5 clusters with 3 nodes, (3 x 4 =12 and 5 x 3= 15) in this case you have 8 clusters and 27 nodes. If you want to have more nodes you can, but you will need to either add the nodes to existing clusters or use the conventional method of Modbus Plus network with the use of T-Taps and drop cables up to the 64 node max. with out a repeaters.