Applies To:
  • CitectSCADA 5.20

Summary:
When connecting to the RS Linx OPC Server or server emulator you will receive an error when the Items (Tags) are added. Also the Server will most likely crash. 

Solution:
This is a problem in the RS Linx OPC Server.  Whenever items are added it will return an incorrect error and crash whenever a requested data type is specified, even when it matches the server type.  It will only work when it is requested to use the native data type.  To make our OPC Client driver work we have added a workaround where we only request to use the native data type.  This workaround can be enabled by the Citect.ini parameter...

    [OPC]
    AddItemAsVtEmpty=1

This may have performance effects when reading the data as we cannot guarantee that we are obtaining the data in the required form.  So if the OPC Server gives us data in another type that is different than Citect data type mappings then it must be converted. This conversion takes time and may decrease performance.  Only use the above workaround when absolutely necessary.

The above workaround is enabled in the OPC Client driver shipped with Citect for Windows 5.21.

 

Keywords:
 

Attachments