TimD
Lifetime Supporting Member
Hello All.
I have a flowmeter with a pulse module. The flowmeter generates one pulse per gallon. I am reading approx. 5GPM. The pulse width is approx 2-sec.
I am sending 24v through the meter's pulse module, every pulse is 'seen' by the controller and through a one-shot, recorded. I am using an ADD block because it's count resolution is 9,999,999
I created a counter (see above) with help from this thread yesterday that works perfectly. I set my totalizer to match the meter and for 10 minutes the count was absolutely perfect, however, I let the controller count away overnight, when I showed up this morning, my gallon reading on the flowmeter was off from my plc version by almost 5% (flowmeter was ahead).
My initial thoughts were perhaps I need to execute the pulse read code more often than the rest of my ladder code? The manufacturer (GWF) swears that the mechanics and pulse module are dead-on.
My program is about 90 lines of ladder, no subroutines, two PID loops (0.30 sec rate).
If anyone can shed light on my dilemma, please do! Any help appreciated.
I have a flowmeter with a pulse module. The flowmeter generates one pulse per gallon. I am reading approx. 5GPM. The pulse width is approx 2-sec.
I am sending 24v through the meter's pulse module, every pulse is 'seen' by the controller and through a one-shot, recorded. I am using an ADD block because it's count resolution is 9,999,999
I created a counter (see above) with help from this thread yesterday that works perfectly. I set my totalizer to match the meter and for 10 minutes the count was absolutely perfect, however, I let the controller count away overnight, when I showed up this morning, my gallon reading on the flowmeter was off from my plc version by almost 5% (flowmeter was ahead).
My initial thoughts were perhaps I need to execute the pulse read code more often than the rest of my ladder code? The manufacturer (GWF) swears that the mechanics and pulse module are dead-on.
My program is about 90 lines of ladder, no subroutines, two PID loops (0.30 sec rate).
If anyone can shed light on my dilemma, please do! Any help appreciated.