Long range readers have a very important role in access control systems. The type of card or tag to be used & detection range of the reader determines its application in the field of access controls. The UHF RFID range can be from 1 Meter (100cm) to several meters and in general the maximum is twenty meter (20cm), meaning that the existing UHF reader must detect the UHF card or UHF tag at such distance. Why range of detection determines the application and how it solves the real time problems. Obviously behind every application is the project requirement. The long range readers are well suited for car parking areas, hospital entries and exits for people of determination, high security zones etc. A simple UHF long range tag solves many problems onsite. The principle is simple: the reader detects the UHF tag or card, and transmits data to the access controller, and in the same time access controller sends instructions to the gate or door to open or stay closed, thus eliminating the manual control at all steps. . Previously it was a low frequency or high frequency card shown to the basic reader at a very small range of 1-5cm (10-50mm), have been replaced by long range reader because of many shortcomings.
Frequency ranges for readers
The UHF long range readers are designed to detect the certain frequency ranges based on the region and principle of eliminating the interference with the existing telecom structure. The frequency spectrum for long range readers are divided in several category, and basic frequency levels are as
| America | 902–928 MHz |
| European Union | 865–868 MHz (European solely depends on the country) |
The type of readers are capable of detecting the UHF RFID tags or cards of EPC (Electronic product code) Gen II (ISO 18000 – 6C), ISO 18000-6B standards. The EPC Gen II air interface protocol defines the physical and logical requirements for an RFID system of interrogators and passive tags, operating in the 860 MHz – 960 MHz UHF range hence covering US & EU frequency band. Nundnet® long range readers are available in EU, US frequency ranges.
Material used for long range readers
The UHF readers are incorporated with the builtin electronic processor boards and antennas in the concealed housing. The housing is usually made of ABS ( Acrylonitrile Butadiene Styrene. The reason for using ABS is that it is an impact resistant engineering thermoplastic and amorphous polymer, very good resistance to diluted acid & alkalis, moderate resistance to aliphatic hydrocarbons. The blending of ABS plastic with the polymers increases the mechanical and thermal properties. ABS is very friend to nature with number #9 hence 100% recyclable, non-toxic and harmless.
Ingress protection rating
Long range reader housings are usually IP55 rated means protected against dust limited ingress, no harmful deposits and protection against the low pressure jets of water from all directions, limited ingress permitted. So in general IP55 is an assurance that the long range reader is protected against a quantity of dust that could interfere with the normal operation of the product but is not fully dust tight. The product is completely protected against solid objects and is also protected against water jets projected by a nozzle (6.3mm) from any angle. IP68 rated enclosures are also available for harsh environmental conditions. Nundnet® UHF long range readers are available with IP55, IP67 & IP68 enclosures.
Card & tag detection range
Every step of installation & product selection counts and plays a vital role in the success of the project. Depending on the application, the project engineers choose the long range readers, typically the detection range is from one meter to several meters. To avoid any implication caused by interference, the selection is to be made properly on the basis of experience and expertise. The height of the pole and angular position of the reader is to be decided and designed wisely to achieve the desired results. There should be the line of communication between the long range reader and the UHF tag or card to ensure speedy detection. It is recommended to go to the installation guide for long range readers and follow the manufacturer instructions. The height & position of the reader depends directly on the position & distance of the UHF tag. Imagine a car, using UHF tag to enter the particular parking zone, so the position of tag can be either on windshield or headlight etc., accordingly the reader is to be positioned. Nundnet® readers are tested for 1Meter to 20Meter range.
| Angular orientation | Height (Meters) | Distance (Meters) |
| 30°~ 45° | 1.8 | 10 |
| 20°~ 30° | 2.0 | 15 |
| 15° ~ 20° | 1.0 ~ 2.0 | 10 |
| 15° ~ 20° | 1.5 ~ 2.5 | 15 |
| 45°~ 60° | 2.5 ~ 3.0 | 8 |
| 45°~ 60° | 3.0 ~ 3.5 | 9 |
Communication ports & protocol in readers
Communication is the soul of engineering. Access control readers communicate using different protocols and procedures. In general the long range readers use the wiegand as a de-facto protocol and the other communication means incorporated with RS232, RS485, TCP/IP and lately OSDP protocol. Wiegand protocol is widely used for existing access controllers, RS485 is used for long distance communication when the cable distance is nearly 1200 Meters. Nundnet® long range readers are compatible with most of the access control readers.
| PORT/PROTOCOL | DESCRIPTION |
| Wiegand | The defacto protocol for communication of different bit width 26~34 can be adjusted based on the compatibility with the controller. |
| TCP/IP | The computer network protocol. |
| RS232 | The serial interface port for testing and updates. Sometimes used for communication with industrial standard products. |
| RS485 | The serial inteface port used for long distance communication. The communication can be extended to 1200Meters |
Certifications for Long Range Readers
UHF long range readers should not interfere with the existing frequency bands hence should be tested for the applicable frequency ranges. The compliances are mentioned as below
| TYPE | STANDARD |
| Safety | EN IEC 62368-1:2020+A1:2020 and EN 62479 : 2010 |
| Health | EN 50663 : 2017 and ETSI EN 300 220-1V3.1.1 (2017-02) |
| EMC | ETSI EN 300 220-2V3.2.1 (2018-06) and ETSI EN 301 489-1 V2.2.3 (2019-11) |
| Radio | ETSI EN 301 489-3 V2.1.1 (2019-03) |
| Ingress | IP55, IP67, IP68 |
| FCC | To regulate all interstate and foreign communication by wire, radio, telephone, telegraph, and broadcasting in USA. |
Nundnet® UHF range of readers (Short range UHF reader, mid range UHF reader, Long range reader) and other RFID devices comply with the radio equipment directive 2014/53/EU (RED) and all are up to date as per new regulations to comply with all requirements. The test report was issued by one of the accredited lab of International Laboratory Accreditation Cooperation (ILAC).