Hi I know this is a very old post, but I am facing similar issues.

I have connected the same encoder input (single channel A) to I0.0 and I0.1. 

I 0.0 is set as frequency measurement.

I0.1 is set as counter.

Funny thing is- the frequency seems to be correct at varying speed. However, the pulse count obtained from HSC using I0.1 varies for varying speed. Example for lower speeds it is 1024 ppr. but for higher speeds I get around 700 ppr. The ppr stays consistent for that particular speed. But, isnt it supposed to be the same for any speed as long as it does not exceed the hardware capacity (100KHZ in my case).. Please kindly advise whats going wrong.

Thanks,

Rueben

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Split from HSC cant count my encoder pulses at 50rpm.

Hi,

quality of encoder is ok. Already tested using an osiclloscope. (and also with some other PLC brand. it works fine).

But, seems like Im configuring something incorrectly in TIA? (theres hardly anything to configure though). Any thoughts?

Hello.

Hard to say what your issue is without seeing the program. The best guess is that the input filters are set to default values which is wrong for your application. Review the attached image for hints on what to do.

What are your findings?

jacek d

0.1 us seems way too low but I have no idea what are other possibilities for this HW. 1 or 5 us would be just perfect if the limit frequency is 100 kHz.

A worthy comment. The available settings are..

I was waiting for @ruebens to report a change in behaviour. But it is good that you have told him now what is the most optimal option. Can we agree on 3.2us as a good suggestion to not filter out  2 transitions from a 100kHz pulse?

Well wishes.

Regards.

Thanks for the suggestion guys,

But, I have already tried changing the input filters with similar results. I have attached  sample program where I used the encoders with shift register. Please have a look at it

[snip]

The encoder pulses are combined (50 pulses) to create a shifting pulse. The entire program is done in ladder (including the shift). I tried using arrays or bool and shift inside the script, but somehow it turned out to be slower (as the entire array had to be inside a loop). But, thats a concern for later :).

Please have a look as see if anything can be changed. thx

Rueben