so recently we have had a problem with the red encoders in port 4 on the digital part. so what has happened is whenever we plug in an encoder to #4 and another one is that the encoder will only send back two different values one for clockwise and counterclockwise. we have tried using different sensor, cortexes, switching wires, etc. which have not worked, so for now we have solved the problem by replacing that port with a pneumatic and moving the encoder to a different place. My big question is have you guys ever experienced this and have you found a better solution to the problem?
Port 4 and 10 share an interrupt internally in the cortex. Therefore you cannot have a two wire sensor in both port 4 and port 10 at the same time. I’m guessing this is your problem? It isn’t something your doing wrong, it’s a Cortex thing.
See the following link for details.