In Japan, you see many different types of vending machines on every street corner. For each of these machines, it is imperative that the machine be stocked with goods and enough change to take advantage of every possible sale. Effective maintenance of these machines is an important sales function for businesses for which vending machines are a critical business tool. Various systems have been proposed for remotely monitoring the vending machines, including the recently available PHS monitoring systems.

Introduced here is an example of a TIME-d (Toyota Intelligent Monitoring Enhancement for delivery) system, a vending machine monitoring solution, developed by Toyota.
The TIME-d system is made of three components; the center station, the vehicular unit, and the vending machine unit. Each unit is described in the following section.

This is a compact PHS data transmission unit with an internally mounted antenna. Several vending machines make up a Ogroup", within which a miniature data transmission network is established. Data can be transmitted among the vending machines within the same group via the "walkie-talkie" direct communication mode, based on the PIAFS protocol. There is no communication cost for this portion.
One vending machine from each group is designated to transmit the accumulated data to the center station via the PHS public service network. T he communication cost is lower than regular PHS calling rates due to the reduced tele-metering rate that applies to this type of data transmission service. If a vending machine develops a problem, the device also automatically informs the center station.

Vehicular Unit
This unit is a combination of a portable PC, a printer, PHS unit and car navigation monitoring units. The inventory status of each vending machine is automatically downloaded to the PC, including the suitable stock quantity for that particular machine.
A distributor inputs the number of sold and replenished goods, etc. for each vending machine. This information is then transmitted to the center station through the PHS public service network.

Center Station
The status of each group of vending machines is automatically transmitted to the center station periodically. The location of the distribution vehicles is also monitored by the location information service and then indicated on the monitoring screen at the center station.

(Excerpt from the November 1998 issue of the Electronics Magazine)