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Hi everybody ... again it's me with my incremental encoder,

I've tested several things but I stil can't find what am I doing wrong and I was hoping you could help me some more.

The thing is... I've a 2,000pulses/rev encoder (don't ask me why jaja) and I'm sending its signal to a Unitronics M91-2-T1 PLC, but I haven´t been able to count correctly the revolutions I am doing.

Supposedly I preseted my encoder properly, I declared I0.0 & I0.1 as high speed inputs (Hardware Configuration ->M91-2-T1 -> HSI -> High Speed Shaft Encoder (x4)), and I did a Ladder Program that sums +1 and resets the memory where the pulses go, every 8,000 pulses.

Also, I saw the output of the encoder with an osciloscope and they seem to be right. Channel A and B are giving square signals which are 90° out of phase, BUT the Z channel gives me nothing more than trash, it is a noisy signal with no pattern at all (I know this PLC doesn't have an input for this channel but never the less it seems strange to me).

Finally the frecuency I'm working at:

my application has a rotatory velocity of 4.8rev/s (aprox)

encoder = 2000pulses/rev

input = vel * encoder = 9,600/sec

The high speed inputs of this PLC are able to work with frecuencies up to 10,000Hz, I'm working very near the limit but still when i slowed down my application i didn't work correctly.

I think my error is in the PLC: maybe the frecuency, or maybe the I didn't declare the High Speed Inputs in all the required settings.

Thanks a lot to any idea

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