A subnode Subnode (System Configuration) A subnode is a node (PLC) which is subordinate to the manager node ("master node"). All communication to a subnode is handled by the manager node. is a node (PLC) which communicates with IGSS through a gateway node (the Manager node).
All communication between a subnode and IGSS is routed via the manager node which is therefore the communication gateway for IGSSas depicted in the illustration below.
To define a subnode, the following preconditions must be met:
The PLC program in the Manager node must be written to support subnodes.
The mailbox must be enabled for the manager node. The mailbox is an address area on the manager node reserved for communication with the subnode.
All SICOS drivers support subnodes and do not require a mailbox.