Our Scada system will be based on 2 Ignition redundant gateway which collect data from PLC,
with its Vision HMI.
Above this system, another hypervision system (not provided by our firm) will access to our data thru OPC-UA (read only and read/write). Ignition is the server and this system the client.
If the master gw and the backup gw both expose the data it could be difficult for these system to choose the right gw (the active one) especially for the write request : need to check gw status tag…
This hypervision system would to set its opc-ua client connection with master gw as primary connection and backup gw as fallback connection.
So if the gw is not the active part of the redundant system, the tag are not exposed or the opc server refused the incomming connection, to force the client to connect to the active gw.