Posted 8 Oct 2008 Hi I have recently experienced a problem on a S7 300 system which is connected to a SCADA system running on WINCC. Virtually every time I disconnect the MPI connector on the CPU that connects to the SCADA the batching system which is controlled by the PLC, starts to under dose after I reconnect. Only one of the systems which is controlled by the PLC never under doses and this system is not on the SCADA. The reason it is not on the SCADA is that all the tags on the WINCC are used up to the hilt. Has anyone experienced a simular situation or does anyone know what would cause this. Regards Ed Share this post Link to post Share on other sites