I was surprised at how strange these protocols are between the control boards and coin handlers. There is a real lack of feedback on what is going on, and more modern payment systems like RFID wallet cards use the same protocols. I wrote a post about some of these holes a few years ago: http://cybergibbons.com/uncategorized/cashless-vending-fail-analysis-of-a-rfid-payment-system/ Report comment Reply
I was surprised at how strange these protocols are between the control boards and coin handlers. There is a real lack of feedback on what is going on, and more modern payment systems like RFID wallet cards use the same protocols.
I wrote a post about some of these holes a few years ago:
http://cybergibbons.com/uncategorized/cashless-vending-fail-analysis-of-a-rfid-payment-system/