Applies To:
  • CitectSCADA 4.x, 5.xx

My customer is using a large LAN with more than 100 connected users and four Routers.  I am unable to get the communication between my Citect IOserver and my Citect display clients up and running despite that I can "ping" the computers in both directions.

When I use the TraceRT command from the command line of NT I can se that my ping makes three router jumps.  If I test the communication without having any router between it works just fine.  What is wrong?


This problem has probably something to do with the configuration of the routers.  Probable cause could be that the ports137 and 138 are disabled on the routers.  As Citect is dependent on NetBT (NetBIOS over TCP/IP) to establish contact, it will fail as NetBIOS is disabled on the routers. This is the most common way to configure routers that are connected to the Internet because of security reasons. You have three ways to solve this problem.

Try to persuade the LAN system administrator to change to Router settings.

This is probably the most difficult approach.

Use the IDC (Internet Display Client) See also KB article Q2751

Modify your LMHOST file. See KB article Q2173.

"How do I setup Citect to run across the Internet?"

See also KB article Q2533.