reset process

hey....i am doin a technical thesis project using the allen bradley micrologix plc. my process is set up and working properly, but i need it to reset once the process is over and start again. my logic consist of timers and counters. i've tried everything but the right thing. suggestions anyone?????

You may accomplish what you need by having a "Process Complete" coil turned on at the end of the last step by the last timer or whatever. A contact for this coil would then be placed in the rung for each timer, counter, holding coil, and so on. The coil could be a one shot, or you could have it hold itself on until after the next scan and have it reset itself with a contact from a "Reset Complete" coil.

I agree with Tom.

The way i've always done batch processes is to latch each step after completion. When the previous step is complete and latched start the next step. the final step would be to reset all the previous latches allowing the process to restart from the beginning. The simpler the better.

This format has served me well for applications like the food industry where you are adding together different ingredients and quantities into a single weight measurement vessel. Each ingredient would basically be a step.

Cheers,

Lee

Another method is to move a step number to a holding register after each step.
Then you can restart anywhere in the process by moving the desired step number in to the step register. When the process is complete you can move a zero into the step register for system IDLE or READY.

got er figured out

first of all, thanks guys for ur advice, i really appresiate it.

we got our process to restart by using "RES" command for timers and counters. at the end of the process we used a limit switch to impliment a counter (C5:4) to rest all counters in the process, including C5:4.
we then discovered that when u use a counter to reset itself, u need to include a "time on" delay timer to delay resetting. (approx .25 sec). then we adjusted our counters and our process resetted when needed, resulting in a continuous process.

once again, thanks....and i guess our project will be marked "complete"