Hi, thanks for all the responses. You may be correct that it is not Ethernet, that is what it looked like. The control panel all of the buttons, but is overly complicated for just speed and brings up errors as the incline motor isn't attached. I had read on some websites (now can't remember which
) that the PWM could be controlled with a pot, but this may only be the case for a few controllers.
My understanding was that there was a small voltage sent from the control panel to the motor control bit that altered the PWM with the change in voltage. Therefore a potentiometer could easily control this voltage.
Thanks again