I have a stepper control using a 5/03 and the 1746-hstp1. The system has been in service for a few years. Recently the customer has requested that we use an encoder to get confirm the position. I have changed the configuration for a quad encoder but all I am getting when the stepper moves off the home limit is 25999 for a reading and it never changes after that.

The card does not show any errors after config. I have checked the encoder output with a scope and it looks good. What am I missing?

 

We have encoders on some high speed vacuum compressors. The manufacturer wanted to put the PLCs in the field. However at our site we have some corrosive products and we wanted to put the PLCs inside our Motor/Electrical centers. We found out from supplier that we are limited by distance of 300 feet due to voltage drop. Take a look at the distance of your interconnect cabling and see if you might be getting to high a voltage drop. Or you possibly could have wrong size cable and due to the high frequency of encoder the signal is attenuated below threshold of PLC card to sense. Confirm you have correct size gauge wire for application. Just some quick thoughts.

Hope this helps