Re: 4th axis kl-4030 and c10
Is your A axis connected with pin 8 for step and 9 for dir?
If so, can you put your multimeter probes (measuring voltage) between pin 9 and GND (on the output of the C10), and then use Mach3 to jog the A axis in one direction and then in the other direction? You should see close to 0 volts when jogging in one direction and close to 5V in the other direction. If you don't see the voltage change when the direction changes, try probing the input to the C10 (right at the DB25 connector) to see if the voltage changes there. If there's no voltage change at either the C10 output or the C10 input then you might want to focus on either the Mach3 configuration or else the UC100.