Long range proximity (prox) readers have a read range from three feet to over three hundred feet depending on the system. Long range prox readers requires special prox cards or tags and prox readers. Long range prox cards are used to tag vehicles, assets, and heavy equipment so they can be tracked as they pass a specific point. The long range prox reader systems are divided into two categories, active and passive.
The active system has a prox card reader that is strategically located to receive a signal sent by the active tag, similar to a radio receiver. The active tag contains a miniature long life battery. The active tag, continuously sends a coded pulse similar to a radio transmitter. The long range reader receives this coded pulse, converts it to a weigand signal and sends it to the controller which makes a go, no go, decision. The active tag is more reliable then a passive and has a range of 300 feet. The range of the signal can be adjusted from 300 feet to as little as 6 feet by a computer program The direction of the signal can be controlled by directional antennas. This feature makes this product perfect for asset control to avoid theft of high risk inventory or assets. Various styles of tags are available for these applications. Tag life is 5 plus years depending on the pulse rate. Tri-Cor stocks AAID active long range readers in stock. To learn more about this product go to the Vuance page.
The passive system has a prox card reader that is similar to a transceiver. The reader is continuously transmitting a signal in oval pattern approximately 6 feet wide by 12 feet long and then receives a return signal from a passive tag. The passive tag does not contain a battery, but receives power from the prox card reader transmission when it enters this zone. The passive tag stores this energy in an electronic circuit until it has ample power to return a coded pulse to the prox card reader. This coded pulse is then converted to a weigand signal and sends it to a controller which makes a go, no go decision. The range of a passive system is limited to nine to twelve feet. The passive system's technology requires accurate alignment of the prox reader and the tag. Luxury car windshields contain a metal film that may reduce the range considerably so a alternative exterior tag mounted to the vehicles grill may be required. The passive systems performs best where a majority of traffic are automobiles passing through a restricted lanes such as public parking garages. Tri-Cor stocks AWID passive long range readers in stock. To learn more about this product go to the AWID page.
Selecting a System
The choice between the two technologies is application driven. The active system serves best in applications with varied vehicles such as trucks, cars, step vans are using the same entrance. The passive system serves better where passenger cars are entering though a controlled lane of traffic, such as an entrance to a condominium. Call a Tri-Cor customer technician to discuss your application today.