measuring Conveyor displacement

I need to measure a Conveyor belt displacement (running) in relation to the DRIVE ROLLOR revolution.

I understand ppl use encoders for this.
I have used encoders but not in its purpose.
I've used encoders to call interupts on the 'O' pulse, call functions between ranges etc.

I would like you gurus to advise me If I'm adapting the right strategy,

I intend to install INCREMENTAL ENCODER, measure how much resolution I get in a unit of displacement, and trigger this unit for every given pulse I received from the Encoder (A pulse)

of course accuracy has a lot to do in what I ask, but if someone has worked on such a system, he would be best to guide the DOs and DONTs.

Any help wud b appreciated

Normal method is to ensure the pulses are slower than a single PLC scan and move a pseudo position each pulse.

In the meantime can you use a tach to measure the difference.
The reason I ask is the drive rpm faster than the conv. belt.
Is this a servo conv. that is vfd driven?
Just wondering for my own understanding
PH.

God bless all of you!

2bON2b said:

You’re on the right track. PeterW is right you need to watch you encoder HZ and your PLC scan time. You can work around this by using a cyclic interrupt to save your pulse counts and then calculating the difference between the saved value and the current value. Also don't forget about the overflow.

Click to expand...

I track on conveyors all the time and have never used an absolute encoder, so have never had an overflow problem to think about. Never needed a cyclic interrupt either. At the end of the day it depends on your pulse speed and desired positional accuracy.

Have used an encoder with simple on/off input or a proximity sensor on a toothed wheel.

Always ensure, whatever the device to fit to non driven end.

peoplehouse said:

In the meantime can you use a tach to measure the difference.
The reason I ask is the drive rpm faster than the conv. belt.
Is this a servo conv. that is vfd driven?
Just wondering for my own understanding
PH.

Click to expand...

Its the belt you would measure so drive rpm is irrelevant.

I need to measure a Conveyor belt displacement (running) in relation to the DRIVE ROLLOR revolution.
What exactly are you trying to do, measure belt slip?
If it's simply speed PeterW is right, measure the speed of tail pulley with a simple proximity switch, or one of the return idlers.
Regards
Roy