Rfid technology: how do radio frequency readers work?

There are various applications of radio frequency technology in both everyday and industrial activities. In fact, this Rfid technology has been available for many years in the logistics sector (it was already present in the 1990s) and has therefore been able to spread to various environments, although it has not yet become a real ‘killer technology’.

The operating logic is quite simple: the RF-ID tag systems we often see in the form of labels (we can make the bar code analogy) consist of an antenna and a microchip in which ‘non-volatile’ information is stored.

When a magnetic field, generated by the reader’s antenna, ‘activates’ the microchip via this antenna, the codes that are stored inside are sent, thus making them ‘readable’.

The reader is also composed of an antenna that can not only receive, but also transmit a code and write it on the microchip.

The frequencies used are varied; the one that has the most use today is UHF using a range between 860MHz and 960Mhz. The advantages of this Rfid technology is that it can recognise passive (non-battery) tags up to 8-10 metres away.

Readers and antennas can be either fixed gateways or handy devices equipped with antennas, the latter being highly efficient in terms of reading distance. An advantage of the hand-held terminal is that it can quickly read very large areas, simply by moving along aisles, and above all it can achieve a higher reading efficiency than a fixed gate.

From a physical point of view, in fact, if the RFID tag has an inclination angle of 0° with respect to the magnetic field generated by the reader’s antenna, the tag is not read (an inclination of at least 15-20° is required). In the case of a reader held in the hand and ‘shaken’ in different directions around the reading area, there is an almost absolute guarantee that at least at one moment the angle will not be 0°.

Other tags currently widely used, for logistics management with Rfid technology, are those with NFC technology, also used for electronic payments (integrated in credit cards and smartphones). In this case, reading is by contact only.

SYGEST has been approaching this technology since its inception, implementing a system to track tuna trays inside a plant with sterilisation autoclaves as early as the late 1990s. At that time, the use of tags with RFID technology was not possible due to the high temperatures reached: 125KHz tags with a reading distance of no more than 20-30 cm were used.

Again because of the need for tracking in the food sector, around 2005 new activities were carried out to recognise hams and cheeses looking for particularly innovative solutions for the period.

Today, Sygest proposes the “Tag-RFID” App, its own solution developed for the traceability and identification of goods based on UHF RFID technology using tags.

The system ensures timely control over warehousing and shipments and superior organisational efficiency.

The Tag-RFID App is developed on the Android operating system and installed on terminals equipped with a UHF RFID reader, with a reading power, in free field, of up to 6 metres (with some terminals even 8-10 metres).

UHF RFID technology is increasingly in demand in the field of logistics and traceability because it enables the unambiguous detection of both stationary and moving objects.

The use of RFID technology makes it possible to drastically reduce tracking times and errors and proves to be, in every respect, an effective and efficient solution for automating a company’s logistics and production processes.

App Tag-RFID functionalities are:

• Search for ‘visually not found’ parts – to locate items and components, previously labelled, within a warehouse or in an open field.
• Check shipped packages – to check whether all packages in a shipment are present. The list is loaded by reading a QR Code or from the company ERP and the check is made in real time with immediate display of the presence of the items.
• Inventory – to take a physical inventory of the materials present in a certain location or to check the material being shipped by verifying the actual quantity for each item.
• Integration with Packing List Photo application.