Applies To:
  • CitectSCADA 2.00 2.01 3.00

When trying to retrieve data from a TOSADMAP IODevice, all that is displayed is a #COM symbol and the IOServer yields a "Unit Offline" message in the kernel. Also, the device is being continually restarted. 

This is a known problem in Citect for versions earlier than 3.4/4.2. It is due to a bug in the TOSADMAP driver. However, there is a work around for this situation. All that needs to be done is to modify the order in which your IO Devices are defined in the project. The rule to follow is to ensure that all physical devices are defined before any memory based or disk based devices.