XK-R

Right the situation:

I have a PLC which monitors exhaust gas every 5 mins. The time interval cannot be changed. Sometimes the engine drifts out of range due to the gas mixture used which I cannot regulate. When it drifts, it raises an alarm on the PLC and this will not reset until it has been acknowledged. By this time the engine has drifted back into range again but it simply doesn't carry on monitoring once it has alarmed. Spoke to the manufacturer and this cannot be changed. So it is a PITA to keep having to check these permanantly.

I have a positive and negative signal I can tap into when a alarm is raised. What I need is a small PLC board with some kind of chip which monitors when I get a closed loop signal from the alarm, waits 5 mins before sending a closed loop signal back into the manufacturers PLC which I can tap into to clear the alarm.

I don't see it being hard at all, but wouldn't know where to start to find a chip to do this for me? I can solder the boards etc. etc. and install myself no probs.

Cheers.