Iam using a plc simatic s5 115 U (siemens ) my problem that there is no output on CPU (943 B) there are 2 selector switches one RN/ST with 2 indicators RN/ST the other selector NR/RE/OR with 3 indicators QVZ/ZYK/BASP , the indicator ST is blinking although the selector switch selected to RN, after that we disconnect the input/output modules plus serial interface 810 ,but the result is the same that ST indicator is blinking although the selector switch on RN position , please your help in solving this problem .
thanks and best regards.
thanks and best regards.