im151 blinking
we are using the same plc s7 400,in our cement plant.bus fault occurs due to bad end termination of profibus cable.profibus cable is parallel to all IM 151 modules but profibus cable at IM151 module end should be terminated (i.e physically last IM module in profibus network). end termination is done by puting the dip swith "on" which is provided on profibus connector, remaining all profibus conectors dip switches are in "off" position other wise bus fault will blink.
system fault will occur when all modules which are assigned in plc project are not recognised by the plc. both problems are related,