Applies To:
  • CitectSCADA
  • CitectHMI

I followed the instruction provided in the CitectSCADA on-line help to disable one of I/O Devices in my project. I added [DisableIO]IODevice01 to Citect.ini file, but it didn't work. Is the syntax of this parameter setting correct? 

The information given in the on-line help is not very clear and no example is provided. The correct usage of these parameters should be

<Server Name>=1
<Device Name>=1

For example,


where IODevice01 is a IO device and IOServer03 is a IO server in your project. This settings will disable IODevice01 and all IO devices associated with IOServer03.

To enable these IO device and server, simply delete the settings from Citect.ini file or assign 0. If you want to comment out the settings, use character " ! " NOT " ; ", otherwise CitectSCADA may hang on start-up. It is noted that parameters of [DisableIO] are not standard ones. On start-up, CitectSCADA tries to load all device names into a symbol table and use " ; " to separate them. If " ;" is used to comment out [DisableIO] parameters, it will send initialisation of client system into a dead loop.

This parameter is very useful feature to bypass connecting to I/O Servers on start-up when there are a very large number of I/O devices and some of them don't exist yet. This parameter is used to permanently disable an I/O Device, so that no HW errors are generated. Disabled devices may be temporarily enabled with the IODeviceControl() function, but the I/O Server will start up with them disabled as long as the DisableIO parameters are set.