Long-Range UHF RFID Readers for Parking, Boom Barriers and Vehicle Gates

Why card readers slow down vehicle gates

At a boom barrier with a short-range card reader, every driver has to stop, lower the window and reach out with a card. Queues build at peak hours, cards get passed from driver to driver, and a reader at window height takes knocks from mirrors and weather.

Parking garages and lots, residential compounds, office campuses, fleet yards and industrial sites need something else. The vehicle should be identified as it approaches, the existing controller should make the barrier decision, and every entry and exit should be logged against a vehicle record.

How UHF vehicle identification works

Each permitted vehicle carries a passive UHF tag built to the EPC Gen2 (ISO 18000-6C) standard, usually a windshield sticker or a headlamp tag. The tag has no battery. A long-range reader on a pole powers it from several meters away and reads its EPC number.

The reader does not decide who gets in. It passes the tag number to the system you already run:

• an access controller, over Wiegand 26 or 34, the same input a door card reader uses, or
• parking or site software, over RS232, RS485, USB or, on E-type models, TCP/IP.

The controller or software checks the number against its list, opens the barrier and records the event. Visitors without a tag are handled at the same entrance with a QR pass or a card, as described below.

Our integrated long-range UHF readers put the reader and a 7 to 12 dBi antenna in one outdoor housing with a pole or wall bracket. There is no separate antenna or coaxial cable to install.

Choosing the right reader

Antenna gain sets how far and how wide the reader sees. Choose the smallest reader that covers your read zone, because extra range also picks up vehicles queuing behind, in the next lane or parked nearby. RF output is adjustable in software from 0 to 30 dBm on every model, so you can trim the zone on site.

The U620-M (8 dBi, 0–5 m) sits between the 7 and 9 dBi models. The rated ranges come from the product specifications. On site, range depends on the tag, the windshield, the mounting height and the angle. For the physics behind it, see UHF RFID read range, and for form-factor trade-offs, fixed vs integrated vs handheld UHF readers. The visitor readers are listed with our other QR code access control readers, and the driver-card readers with the Wiegand access control card readers.

Mounting a UHF reader at a boom barrier or parking garage entry

Where the reader goes matters as much as which model you choose. These points apply to all the integrated readers; each product page gives the bracket and pole details.

• Beside the lane, aimed along the approach. Mount the reader on a pole or wall bracket beside the boom barrier and aim it down the approach lane rather than across the lanes. The tag should enter the read zone before the vehicle reaches the barrier arm, so the controller has time to open the barrier.
• Height and pole size. The installation notes call for a reader height above 1.8 m for the 9 dBi U630-M, and are based on a 2.2 m pole for the 10 dBi U640-M and the 12 dBi U650-M. The brackets take 40–60 mm poles (U630-M), 30–50 mm poles (U640-M) and 40–80 mm poles (U650-M), and all three can also be wall-mounted.
• Trim the read zone. Start at a moderate RF power in the demo software, drive tagged vehicles through the lane and past the neighboring lane, then lower the power or re-aim until only the intended lane is read. Extra range also picks up vehicles queuing behind or parked nearby.
• Parking garage entries. Where headroom or ramp space leaves no room for a pole, use the wall bracket. Concrete walls, steel doors and parked cars reflect UHF signals, so the read zone inside a garage can reach further than expected; set the power on site with the garage in normal use. A 7 or 9 dBi reader is usually easier to confine to one garage lane than the 12 dBi model.
• Cold sites. The U630-M is rated from -40 °C to +65 °C; at cold sites, let it warm up for about 15 minutes after power-on before you test. The U640-M and U650-M are rated from -20 °C to +65 °C.

Integration notes

Wiegand to an access controller. Connect D0, D1 and ground to the controller’s reader port with shielded cable. Wiegand 26 carries 24 data bits and Wiegand 34 carries 32, so the controller gets part of a typical 96-bit EPC, not all of it. Enroll each tag by the number the controller reports, and before rollout, check with us which part of the EPC is sent. Wiegand 26 vs 34 covers the bit layout, and the card number converter helps you check the numbers.

Serial and network links. RS485 suits long cable runs from the lane to a gatehouse. RS232 and USB suit a PC close to the lane, and TCP/IP on E-type (-N) versions puts the reader straight onto the site network. The SDK includes sample code in C#, VC, VB, Java and Delphi, plus a demo for reading, writing and issuing tags. The interface guide compares the options, and all serial models are listed under RS232 and RS485 readers.

Triggered reading. Each integrated reader has one trigger input. Wire a loop detector or photo-eye to it and set the reader to triggered mode, so it reads only when a vehicle is in position. Continuous mode reads whenever a tag is in the field, which suits lanes without a detector.

Frequency band. The integrated readers are supplied for 902–928 MHz or 865–868 MHz, and other bands can be ordered. The desktop reader/writers are listed for 902–928 MHz or 920–925 MHz, with other regional bands on request, so confirm the band of the enrollment reader as well. State the country of installation on your RFQ. For a boom barrier project in India, order the 865–867 MHz band commonly used there. The frequency band guide lists the common allocations.

Power and sealing. Plan a 12 V DC supply for each reader; the 8, 9, 10 and 12 dBi models are specified at 12 V DC, 3 A, and the 7 dBi model at 9–12 V DC. No IP rating is published, so include any sealing requirement in your RFQ.

Windshields. Tag position affects range as much as reader choice. Include vehicles with athermic or metal-coated glass in your pilot, and plan headlamp tags for any that do not read reliably through the windshield.

Visitor QR codes over Wiegand. On the Q420-M, QR content sent over Wiegand must be a hexadecimal card-number string. The Q430-M sends QR content over Wiegand as a decimal number by default. Set your visitor-pass software to generate codes that match what your controller expects.

What to send us for a quote

A complete brief lets us match the reader, band and output to your site. Please include:

1. Number of lanes, lane width, and where the reader can be mounted relative to the tag and the boom barrier.
2. Country of installation, so we supply the right UHF band.
3. The controller or software that receives the ID, and the input it accepts: Wiegand 26/34, RS485, RS232, USB or TCP/IP.
4. The tag you use or plan to use, and the vehicle types (cars, vans, trucks, buses).
5. Whether you also need enrollment desks, driver-card readers or visitor QR readers.
6. Quantities, and any OEM needs such as logo or firmware output; see OEM and ODM options.

Price, MOQ and lead time are confirmed in your quotation. To test before you order, see samples, or contact us with your site layout. For card enrollment desks and door readers on the same site, see card enrollment readers for access control.