Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 2.00, 2.01

On a network, Windows does not prevent you from replacing the CITECT.EXE file with a later version. Windows normally keeps the EXE file open while Citect is running so that you cannot overwrite it. It may close the EXE, however you should never overwrite as it may cause Citect and/or Windows to crash.

Never replace the CITECT.EXE or any other EXE file which is currently running. This is because Windows may in the future try to load some information from the EXE file and if it has been changed the wrong information will be loaded and Citect or Windows may crash. 

If you want to upgrade to a new version of Citect on your running plant then use the following procedure:
  1. Backup your projects.
  2. Install the new version of Citect on a new directory on the file server. For example existing Citect may be in E:\CITECTA and new version in E:\CITECTB.
  3. Restore your projects into the new Citect, then compile and install.
  4. To switch each computer to the new Citect you must edit the CITECT.INI file so that the following parameters point to the new directory:

RUN=E:\CITECT\USER\<your database name>

Most versions of Citect are network compatible so that you can switch each Citect, one at a time - and not interrupt the operation of your plant. For example, if you have 2 Citect Servers and 4 workstations, you can install the new Citect, restore your project, compile it, then run up 1 workstation with the new version and it will communicate with the existing Citect Servers.

During some upgrades, modifications are made to the network communication of Citect. When this happens, one Citect Version will not communicate with another version. If you try to communicate you will get the Hardware error 'Incompatible server version'. If this occurs, you must replace the Client and the Server before Citect will start communicating. If you have two servers you should replace one server, so the existing clients will communicate to the existing server, then replace each client that will communicate with the new server. Finally, replace the other server.