OPC DA Redundancy

[smbunn]

I have a client with triple servers in their large geoSCADA system.  Lets all the servers 601, 602 and 603.  They have set up the Çonfigure Connections tool to have these three servers as A, B and C with different Node Costs under system name 'Local'.  ViewX Client shows the source as 'Local' and then in brackets either 601, 602 or 603 depending on which has the lowest node cost and then also based on what is happening with the preferred server, i.e. is it still available.

All good.

But in terms of OPC-DA the three separate servers are registered with OPCEnum into the registry so something like Matrikon OPC Explorer shows three separate OPC sources labelled Serck.ScxV6OPCDA.Local.601, Serck.ScxV6OPCDA.Local.602 and Serck.ScxV6OPCDA.Local.603.

This implies that redundancy is NOT handled by the Configure Connections tool and I have to create three separate connections to the three separate OPC DA sources and then somehow figure out which one is currently active.

Am I missing something since ViewX Client seems to be fine with the connector at the top of the tree?  Is there some way of connecting OPC DA at the top of the tree at just Serck.ScxV6OPCDA.Local  rather than Serck.ScxV6OPCDA.Local.601?

[AndrewScott · Accepted solution]

It is up to the specific OPC DA client application to support redundancy as Microsoft COM (which OPC DA is built on) doesn't have any concept of redundancy.

Matrikon OPC Explorer doesn't support redundancy, but the Geo SCADA Advanced OPC DA client driver does support redundancy.

The Configure Connections tool is just a tool for defining settings, nothing more.