Have installed the OPC Server on the Citect server. Everything seems to be correct but I still only get #COM on the image page.

Citect is set up for DA 1.0 OPC Servers. PiiGAB M-Bus OPC Server supports version 2.00, 2.05 and 3.0. This means that you need to add a setting in Citect.ini. Under the [OPC] group, enter UseOPC2=1.