CDT= Car Door Lock Terminal
CD= Car Door lock relay energized
HDT= Hall Door Lock Terminal
HD= Hall Door lock relay energized
When you cycle door these should go off and with doors closed should be high (on). I have a 4 stop hydro unit that lost that input due to door lock voltage being low. We had to solder a wire on spare input on board RDHV 9608v1 board it’s behind HYD 9806 control board on left usually if it’s a hydro. If you have a hydro version hope this helps.
