I've build a simply control panel at work to control conveyor belts, the conveyor belts are controlled by push buttons simple stop/start. before you can start the system you must reset two cat 4 safety relays one for e-stops and one for interlocks, then you can press the button for a pre-start siren to go off, which then sends power to the push button so you can start the system. is there something I can add so when the pre-start goes off you must press a push button within 30 secs or so. if you don't your got to start the whole process again. Cheers Andy
