Applies To:
  • CitectSCADA x.x

Question: Why (a very low level explanation) the parameter [lan] groupname=0 enables RAS to work? 

To establish network sessions with NetBIOS you must register yourself a name. You can either register a group name or unique name. If you register a unique name then your name must be unique on the entire network. If any other computer is using the same name the registration will fail. If you register a group name then it can be the same name as another group name. Group names are normally used when all the computers have some relationship.

As a default Citect uses NetBIOS group names when it registers a local NetBIOS name. We use group names to make the configuration of Citect simpler. If you register a unique name you must get a unique name from the customer. So the customer must configure the unique name correctly or Citect will fail to startup correctly. When we use a group name we always use the same name "CITECT STATION50" so the user cannot get it wrong.

The problem with RAS is that it does not support group names correctly. This is to be expected as group names are not very compatible with WANs as it is very difficult to manage group names over a very wide area network. So to make RAS work you must tell Citect to use unique names by setting the [LAN]GroupName=0 parameter. Citect will use the [LAN]Node name as the NetBIOS name.