coinco 9302gx mdb protocol help

i got a coinco 9302 gs coun changer unit from ebay and it uses what looks like serial data and i was wondering if anyone has managed to get the unit to take coins via a signal from an arduino?

it is the mdb system.

short of identifying and buying the controller board for a vending machine or a coinco tester both of witch is going to be expensive i think i can get it to work from an arduino.

dows anyone know what protocol it uses if it even standard serial and what baud it is?

Shouldn't you be looking on the manufacturer's website for a datasheet or ask the seller on eBay if he has one?

there is nothing on it the only thing on that model is the service manual it only shows the pinout for the plug.

24v + power ground communication ground master transmit and master receive .

i was hoping someone would have worked with one of these and would at least know maybe what baud it uses.