Encoder error monitor for Step 7

Hi'

I am looking for a good idea to make sure that my incremental encoders are working, perhaps with an adjustable offset.

Today I take the actual value of the running encoder, move i to a temp word, then compare it with the value from the previous scan. This partly works, I just think it is to sensible.

So does anyone of you have a good idea to monitor an encoder ?

Thanks
Brian

I used step 5 in university. Right now, i am much more working on
Twin CAT.

In Twin CAT i compare with Reservor value. That might be another solution.