Hi , I have a cnc lathe with two parallel ports working correctly. I installed the SS and the first parallel port works fine but the second barely responds.

 The first port is used to command the axes and some inputs and outputs, the second parallel port use to communicate with a PLC that performs tool changes and moves the spindle motor. I have written three macros in M3, M4 and M6.

 With Output3 and Output4 i send to the PLC the spindle speed and Output5 and Output6 send the tool. However, the PLC moves the magazin without stopping or turning the spindle at a very small or do nothing. I tested three versions of Match but the result is the same.

 I can be doing wrong or there is any conflict with the second port?

regards
Renato

In the SmoothStepper configuration you have to tell it how you are using pins 2-9 (input or output). Since these are dual purpose pins, and for compatibility reasons with some breakout boards, these pins also do not have pull up resistors on them, they have weak pull-down resistors. Depending on what device you are communicating with you may need to add pull up resistors.