Everyone knows how to use a vending machine, but what’s behind the brightly lit door?
Modern vending several key components: a vending machine controller (VMC), a coin mechanism, a bill validator, and in some cases a cashless peripheral such as a credit card reader or other payment device. This is the standard for North American vending: some countries such as Japan or Hong Kong use proprietary cashless systems without any coin or bill acceptance, and in those cases, the machines will not have a coin mechanism or bill validator.
Vending Machine Controller (VMC)
The VMC is the brains of the vending machine. It drives the display, keeps track of the credit inserted into the machine, and tells the coin mechanism how much change to pay out. Back in the 70s, machines weren’t that smart and a lot of the logic was done by the coin mechanism instead. You might still see some single-price soda machines out in the field with this technology in it. However, times have changed, and modern machines all have a sophisticated logic board inside them.
The operator sets up the machine by programming their desired settings in to the VMC, such as pricing or custom messages. Most standard VMCs come with features such as non-resettable sales counters, winner mode (every X vends gives a free vend), discount pricing (depending on time of day), and more. The vast majority of operators don’t use these extra features, and simply set the price for the item sold.
Modern VMCs communicate with the payment peripherals via a protocol known as Multi-Drop Bus, or MDB. MDB is a common standard by which devices communicate with the VMC. So, if you’re looking to buy a vending machine or payment accessories, make sure it’s MDB compatible. Non-MDB peripherals include single price coin mechs and dumb mechs in a variety of connectors and voltages. These are obsolete and will not work with modern vending equipment.
Another standard that modern VMCs support is one for data exchange, or DEX. DEX is a protocol for collecting audit data from vending machines. This data can be read from a handheld device or remotely via a telemeter.
A coin mechanism identifies the coin inserted and diverts the coin appropriately to a certain change tube, the coin box, or to the coin return tray. Modern coin mechs test the coin in a variety of methods. As the coin is inserted, it travels along a rail inside the coin mechanism. Certain characteristics of the coin, including metal content and speed that it rolls, are used to identify the type of coin. Gates inside the coin mechanism then reroute the coin appropriately.
The coins that are inserted may be used to replenish change tubes for providing change to other customers, or diverted into a coin box for collection. Different models of coin mechs have different methods of paying out change: some use a belt system driven by a motor, others may have individual motors or solenoids to pay out coins. Sophisticated models of coin mechanisms also use sonar sensors to detect the amount of change held in each tube. This enables precise tracking of coin inventory.
A bill validator reads and stacks bills inside the machine for collection. When a user inserts a bill, optical sensors read characteristics of the bill to determine its denomination and authenticity. It is rejected and returned to the user if the validator cannot validate the bill appropriately. Most machine in the United States will accept $1 bills, however some may accept higher denominations such as $5, $10, or $20. In the scenario a higher denomination bill is accepted, it is typically paired with a coin mechanism capable of paying out $1 coins. This is to ensure that you won’t get a boatload of quarters when using a $5 bill.
Paying out $1 coins from the coin mechanism still won’t solve the problem of overloading you with coins when you use a $20 at a snack machine. Machines that accept $10s or $20s usually have bill recycler, which pays back $1 or $5 bills to the customer.
In Canada, things work differently as the prolific use of $1 and $2 coins mean that many machines do not have bill validators. You will most certainly never see a recycler: the machines with validators will pay out $2 coins when a $20 bill is inserted.
Cashless is the newest and an emerging payment solution for vending. Although accepting credit cards is nothing new, consumer adoption of the technology is starting to grow. The latest card readers accept not only traditional magnetic stripe cards, but they also accept NFC (near field communication) payment options such as MasterCard PayPass, Visa Paywave, and mobile wallets such as Android Pay or Apple Pay. Certain readers may be integrated with one card solutions to enable processing of proprietary cards such as student cards.