Applies To:
  • CitectSCADA 5.xx

If your Citect implementation is using straight TCP/IP as its networking protocol then after a period of time Citect may stop responding and require a restart.

Straight TCP/IP networking is obtained by the following parameters


This will not effect implementations that also use NetBIOS over TCPIP but will affect Internet Display Clients (IDC) as they also use straight TCP/IP only to communicate.

This problem has arisen due to a bug in the Microsoft networking API that Citect uses.


A work-around has been implemented to detect such a lock-up and to recover.

CIT has confirmed this to be a problem in Citect for Windows versions 5.XX. This problem has been fixed in version 5.40 Spk C