Here is the sheet, documenting the CNC connectors on the back panel, that came with the CNC version of the LTP5500D. As you can see, the Start (CONTROL SIGNAL) is connected to pins 1 & 2 of the 4 pin connector. These two pins connect to the free end of the CrossFire torch control cable - the order isn’t important - it’s just a switch contact.
The Voltage output, which I don’t use yet as I don’t have THC yet, is on the separate 2 pin connector. NOTE: this voltage is a 1:1 divider so is FULL voltage and would need a divider board to process it.
My unit came with the mating connectors, so it was easy to hook up.
