encoder to HSCE help....

I am currently using an encoder with only a single channel (A). I am using a HSCE card in slot 1 to create my RPM sampling off of I:1.3 and multipling by .6. This all works but the encoder I am using has been discontinued by Allen Bradley. The only encoders we carry at the plant have A, B, & Z. I tried using only channel A but get a way off RPM. any help. I was told I have to use what we have in the plan.

Going just by your description, using just the A channel off the other encoder should work(unless the encoders electrical outputs are very different.) It sounds to me like the encoder has a different PPR Pulse-Per-Revolution value. Do you know what the PPR is of both of the encoders? If they are different you could re-scale your multiplier to make the RPM correct. Unless you it's a lower PPR encoder and you need the resolution.

The one encoder with A, B and Z has PPR of 1000. The one with the single output has a PPR of 3000.

aswilson is probably right. I bet your RPM is about 1/3 what it used to be. Change your scaler to 1.8 and you should look alot better.

Keith