I can successfully control stepper motor with my DIO card. But few days ago I get an encoder and tried to connect it with my stepper motor and PCI 6533 as shown in figure below. Then I used MAX`s Test Panels to verify signal`s changes. Outputs worked perfectly but according to inputs...there was no reaction. As I checked it with LPT, everythig seemed to work OK. I used the same optocouples for inputs as for outputs. Is anybody able to tell me where I made mistake ??