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.

You have not mentioned how many pulses per revolution the encoders are. Not all encoders have the same number of pulses per revolution. The encoder you are trying to use should be fine for the application. The model number of the encoders often contain a number that represents the 'PPR' of the encoder. Who are the manufacturers, and what are the model numbers