Wiring VN2700 to a non-MDB ready breathalyzer

[Edgevending]

I have a breathalyzer machine with a coin mech that takes a single coin or token with four outgoing wires 12vdc, Coin, GND, Counter (red, white, black, and gray). I also installed an HSV-300 gamemax Bill Validator which worked fine except the bills would get backed up and stop accepting cash.  The 12vdc to red, gnd to black, blue pulse went to white, and a purple wire had to be grounded to black.  Worked great (accept the backup problem) but I want a stacker and cashless.

okay...so I have a VN2700 24vdc with card reader 4-in-1 that I want to replace the HSV-300.  Is it possible?  I upstepped the voltage and connected the 24v and dc return and got the VN2700 to turn on giving me two flashes in the back (disabled by system).  I tried plugging the Master Recieve, Master Transmit, and Coin Common to the white Coin wire on the breathalyzer, one at a time but no change with the 2-flashes.  I know the credit card reader needs telemetry and card service but I figured the bill validator needed to be working first.

So,  do I need an MDB card of some kind?  Perhaps a new harness may do it?

Any help would be appreciated.

 

[orsd]

Get a Mars amusement validator AE series. This will be able to send simple pulses to the machine. MDB is a complex protocol and so will not interface to your machine, which takes simple pulses to work (typically 1 or 4 pulses per dollar).

[Edgevending]

Thanks.  AE as opposed to VN...makes sense.