What is a subnode ?

Definition

A subnode is a node (PLC) which communicates with IGSS through a gateway node (the manager node).

Manager node and subnode

All communication between a subnode and IGSS is routed via the manager node which is therefore the communication gateway for IGSS as shown below.

$images\net_sub.gif$

Preconditions

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.