Applies To:
  • CitectSCADA 5.41
  • CitectHMI 5.41

I have some IDC clients which connect to my Citect Server via a GSM cellular phone at 9600 baud. I have upgraded my Citects from V5.30 to V5.41 and now my trends do not display correctly. The trend graph does not update, and the engineering units being displayed toggle between the true value and zeros. Clients connected at a faster baud rate via ISDN do not experience any problems. 

The problem is that the trend session between client and server is momentarily being lost. The handle on this session is set to -1 (as seen on 'page table tran' in the kernel) for approximately 1 second at a time before being reinstated. This timeout is occurring in the Server when writing the Trend Response to the socket on which the IDC is connected.

There is a parameter to change this timeout:


The default value is 500 (milliseconds)

Try increasing this parameter to, say, 4000.



1) The change must be made on the Server's 'citect.ini'

2) This parameter does not support alternative citect.ini file names or locations. It will only be read correctly if it is in a file named 'citect.ini' which must be in the Windows directory. (usually c:\WINNT\)