Quote Originally Posted by JAZZCNC View Post
Can't give source where to look but I can explain it easy enough.

The Motion control device provides OUTPUTS which it sends out signals and pulses required to tell the drives which direction and how far to move. These OUTPUTS basicly fall into two types MOTOR OUTPUTS for each Axis and General OUTPUTS which provide 5Vdc Signal.
Each OUTPUT as Positive Negative connection.

So DIR connection is MOTOR OUTPUT and controls the Direction to travel. This is done by sending 0V or 5v depending on direction.
PUL Connection is the PULSE MOTOR OUTPUT which gives stream of pulses relating to how far to move.

The En is Signal to the drive to ENABLE/DISABLE. Often this isn't used and left unconnected.
If used this would be connected to General OUTPUT or could be controlled by external device like relay by sending 5Vdc.

So in your case there will be Pins on the BOB which are MOTOR OUTPUTS and Some which are General OUTPUTS. If using the parallel port they tend to stick to standard arrangement. ie: Pin2 =XDir Pin3=Xpul etc.

There will also be pins for INPUTS.

Hope this helps.
Thank you Jazz,

I think with your explanation (much clearer than a lot of info I have found online) and the one from Neale has clarified things immensely to be honest.

I was having a little play with the BoB today and with a meter I could see the voltages coming out of some of the pins (not quite 5V but 3.6V, which may either be normal or it's because I have had to use a PCI expansion slot in the PC as it didn't come with a parallel port). My next step is to get a dedicated PC assigned for the job, install Win7(32 bit) and then install Mach3. Then I think I will be on the home run!

Thanks again for saving me a lot of hair-pulling.

Rob