Applies To:
  • CitectSCADA

After a trouble free install of the Citect software you find that the IDC clients cannot load pages and appear to freeze. 

The display client mechanism uses FTP to transfer compressed format pages from the server to the client over the internet.

On the client an 'on the fly' decompression is performed and the reconstituted information for the page is loaded.

If this FTP transfer does not complete the page cannot be loaded and the client sits waiting for the process to complete.

A problem has been observed on servers where the Windows FTP server is configured to automatically load at startup as a service. Only one FTP server can be loaded on a computer. The Citect FTP server that is loaded with the startup of the Citect Internet Server soon fails. The original FTP setup on the computer has no details of the Citect FTP configuration and so sits there idle.

Symptoms of this are that on the startup of the Citect server the FTP task that launches on the windows taskbar disappears after a short while. Examination of the Clients shows them to be frozen.

In Win2000 (where the problem was first noticed) the service configuration is found in Control Panel|Administrative Tools|Services. You need to turn off any automatic start of the Windows FTP service.