Product Counter

Hi Guys,

I'm currently in a process of a machine upgrade from relay controls to PLC (compactlogix L23E)and would like to add a rung which gives me the products per min output for the machine(this is a wrapping machine). I sort of want to display this speed on the opeartor panel so the operator is aware of the machine speed(currently there is not system to monitor this). I know this can be doen by using a prox and a sprocket/gear but would appreciate it if someone here could guide me through this. I tried to search the forum but couldnt find anything.

TIA,

Do you want total average parts/minute for the day, or a running parts per minute for the last hour, couple hours, few minutes? Or reset it every minute. Or a continually updated parts/minute based on the minutes/part of an timer which times how long it is taking part to part ("cycle" time). Or a continually updated parts/minute based on the time required to run the last "X" number of parts.

Thanks for your quick reply Tharon. All I need is to know the output of the machine for any given speed. Say for example if the drive motor is running at 950rpm the output is 36 packs per min. It should be continuoisly updated so if the operator changes the machine speed, he is able to know the packs per min at that instant.

How does the operator control the speed of the conveyor now?

Say for example if the drive motor is running at 950rpm the output is 36 packs per min

Click to expand...

What is the relationship between these numbers? Or more specifically, how many pulses of the prox (if it's looking at a sprocket/gear) would correspond to a single machine cycle?

One approach could be: run a self-resetting timer for a specified duration, say 5 seconds. Count the gear teeth during this time. When the timer is done, you could calculate "teeth per 5 seconds" which could be multiplied by 12 to get "teeth per minute." If you know how many teeth correspond to one cycle, you can figure out "cycles per minute."