Applies To:
  • CitectSCADA 5.41

Drivers of type Front End / Back End (FE/BE) allocate resources internally to enable the BE polling of a device.

Typically this allocation is done in the driver upon receipt of a CTDRV_INIT_UNIT command from the IOServer. Once initialised if a device was reported DRIVER_UNIT_OFFLINE consequent CTDRV_STOP_UNIT commands are not sent to the driver. Hence the driver will not release any resources for that device.

As a result in this circumstance is not possible to stop a FE/BE driver from issuing a poll other than stopping the channel or stopping Citect.


CIT has confirmed this to be a problem in Citect for Windows versions to 5.40. This problem has been fixed in version 5.41.