Editor's Note: In the September 2009 Automatic Merchandiser, contributing editors Mike Kasavana and Glenn Butler authored an article on the National Automatic Merchandising Association's "open" technology standards. The article reviewed the progress of the association's technology task force for in developing standards that allow operators to use different providers' products in unified applications. The standards make it easier for operators to use cashless, remote monitoring and vending management software.
In the interest of further educating the vending community on the benefits of these technology standards, Kasavana and Butler prepared another article that examines many aspects of this technology, such as differences between DEX and MDB, different types of data, and why the data is reliable.
There are primarily two types of machine-level data that can be monitored in the vending industry: transactional data and operational data. Transactional data includes facts related to product selection, pricing, sales, and payments while operational data involves error messages, conditional alerts, and malfunction reporting.
Simply stated, vending operators desire technology capable of reliably passing these data from one software application to another, so that multiple applications can contribute to a comprehensive, networked solution. It is for this reason that there is growing interest in developing technology standards that enable data sharing among desperate component parts. Creating a platform for such integration is the work of the NAMA Vending Data Interchange (VDI) Task Force.
DEX and MDB
The NAMA Data Exchange (DEX) standard defines an ASCII data set that can be read from the vending machine using a handheld PC or telemeter (remote communication) device. This data does not include details on every vended product, but instead includes readings from a series of internal meters, that function similar to automobile odometers, designed to track deposited coins and bills, credit/debit card swipes, and column sales.
Vending Management Systems (VMS) and/or telemetry systems can detach (parse) this data and compare it to previous DEX readings to determine coin and bill acceptance, credit/debit card activity, and item sales between readings (interval analysis). DEX can also report a limited number of operational errors (although regrettably somewhat inconsistently) at the time the DEX data is read.
Since most telemetry or handheld PC systems read DEX at predetermined intervals, the DEX data becomes invaluable for cash accountability, pre-kitting (also termed pre-packing), and dynamic scheduling. Unfortunately, DEX is not a "push" protocol and therefore is incapable of providing "real time" notification for machines capable of generating alerts related to temperature variance, bill jams, column sellouts, or other conditions requiring corrective action.
The NAMA Multi-Drop Bus (MDB) protocol, developed more recently than DEX, is a "real time" interface that various peripherals use for communicating with the vending machine controller (VMC). MDB was primarily designed to allow bill validators, coin mechanisms, and card readers to interact with the VMC in such a way that telemetry system could actively monitor connected devices to detect problems (for example, functionality failures) that often occur in the field. In addition, some telemetry devices are capable of recording and time stamping all transactional activity at the machine - thereby providing a higher level of detail that cannot be obtained through DEX data readings.
Transactional data at the machine-level includes purchase price, column location, time of transaction, and method of payment. Together this data can be used to create a transaction record. Fortunately, transactional data can be captured through an electronic control board installed within the vending machine.