Applies To:
  • CitectSCADA 4.x, 5.xx

I have a I/O-server running on a NT 4.0 Workstation and I want to connect 13 Display Clients to this I/O-server but when the eleventh Display Client attempts to connect I get the following error message:

"No more connections are available".

The I/O-server is also my File server.

1. Are there any limitations in the NT Workstation?

2. Does this mean that Citect cannot be run on a NT 4.0 Workstation if I have more then 10 Display Clients?


1. NT Workstation only supports 10 IP Connections at one time. This means that the maximum number of connections to shared directories and printers are 10 at one given moment. If more than 10 shares are needed you need to use a NT Server as your Fileserver for Citect.

2. When the Citect Display Client attempts to connect to the I/O-server it uses the NetBT port and the NetBT port has no limitations in the NT 4.0 Workstation. This logic allows custom peer to peer distributed applications (ie. Citect) to work just fine.

If you want to have 13 Display Clients connected to your I/O-server that is a NT 4.0 Workstation you should not use shares. Run Citect with the project locally installed on every Display Clients or use a NT 4.0 Server as your File Server. The I/O-server can still be run on the NT 4.0 Workstation.