When it comes to staff and asset tracking systems there is a range of potential, and sometimes confusing choices. Although these systems work on the same basic principles, the execution can be different. RFID is one of a variety of technologies used for this purpose.

What is RFID?

Radio Frequency Identification (RFID) is a method of portable information storage. An RFID tag consists of a small memory chip to store information and some sort of radio transmitter/receiver. The tag is read using an electromagnetic field. RFID can be either passive, active or semi-active.

People started exploring the idea of using this method of information tagging in the 1940’s but the first RFID device was patented in 1973. Since this time the adoption of RFID technology has been slow as it was expensive compared to competing systems like barcodes.

Recently there has been more uptake in the use of RFID due to expansions in digital technologies such as smart devices and the internet of things, along with cheaper manufacturing techniques.

How Does Passive RFID Work?

Passive RFID tags are activated via inductive coupling. Inside the tag is a memory chip containing a small amount of information. This memory chip is attached to a radio chip and an antenna for receiving and transmitting signals. The tag is read in the following way.

  • An RFID reading device (or recorder) is held near the tag.
  • The recorder generates an electromagnetic field which then generates a current within the RFID tag antenna via magnetic induction.
  • The current powers the memory chip inside the tag, and a short signal with information such as an ID number is sent back to the recorder.

The RFID tag does not need a battery because it is powered by the recorder, which means that it can be fully enclosed in a durable plastic casing. Some tags are also made from paper, silicon or glass, with a printed metal or carbon circuit.

Are There Difference Types of RFID?

From a technological perspective, RFID is a general concept, and so RFID tags and recorders are manufactured to a very broad range of specifications. For example, UniGuard passive RFID tags operate at a frequency of 125 kHz, which means there is less chance of interference or disruption from Wi-Fi or Bluetooth which operate at a different frequency.

Passive RFID tags are manufactured with three different storage types, read-write, read-only and WORM (write once, read many). The checkpoints used in staff attendance verifications systems require small read-only tags, which are simpler and therefore cheaper. These tags have a pre-assigned unique ID number stored in the memory.

What Are Active RFID Checkpoints?

Active RFID checkpoints are similar to passive tags in that they have an internal microchip for storing and transmitting information, along with an antenna. However, instead of being powered by the recorder, active RFID checkpoints have an internal battery that allows the checkpoint to send out signals up to 100 m away. This mean that active checkpoints cost a little more than passive tags due to more internal hardware.

Within a staff attendance tracking system, active checkpoints are designed to periodically transmit a unique ID number. This is registered by the recorder when in range. The range of the active checkpoint can be varied depending on requirements.

Although RFID checkpoints can be designed to operate at a range of frequencies, they are generally set to work in the range of 2.4000 to 2.4835 GHz because these frequencies are free to operate in, unlike other frequencies that are reserved for special use, or require expensive licences to use.

What Are Some of the Uses For RFID?

Initially the uses for RFID tags were limited to niche markets like monitoring livestock due to the high cost. As the technology has improve the tags have become smaller, more durable, and cheaper. The tags can be used in a similar way to barcodes in tracking items but are more secure. Because of this, RFID is used in a range of applications such as credit/debit cards, toll passes, access keys, identity cards, rail tickets, passports, and pet microchips.

The Good and the Bad of RFID Checkpoints

RFID checkpoints operate in a similar way to NFC tags and Bluetooth Low Energy (BLE) beacons, with one crucial difference. NFC and BLE have been developed to be specifically used with mobile phones, whereas RFID is a more generalised technology.

Although there is nothing stopping manufactures from making phones compatible with a broader range of RFID tags, what makes RFID based staff tracking systems special is that the specialist hardware has been designed and built to industry specific specifications. This means that the recorders are much tougher than standard smartphones with functionality limited to the job at hand. No distractions like social media.

Another big advantage of using a specially designed RFID system is that it is much harder for staff to copy or “spoof” checkpoints. This is something some staff try to do to get out of doing the job by keeping a copy of the checkpoints in a convenient location, and is often done with QR code-based systems.

Best Uses for RFID Checkpoints

Making a choice between using passive or active RFID checkpoints will depend on what is the intended use. With passive checkpoints being smaller, cheaper, and more durable without the need for batteries, and active checkpoints able to be used at a much longer range.

Active checkpoints are best suited to indoor and sheltered areas where staff need to have their hands free for duties such as cleaning, as recorders register the positions of the checkpoints without needing to be swiped. Care does need to be taken when positioning checkpoints as recorders can detect more than one checkpoint at a time.

Passive checkpoints are inexpensive and versatile, being able to be used in all other situations, both indoor and outside. Tag can be placed on walls, doors or other objects such as bin and require contactless interaction by swiping over the tag.

Summing Up

RFID-Based staff tracking systems are a good alternative when a durable real-time system is required. Being purpose-built, along with the software, the hardware is design specifically to industry standards in terms of durability and functionality.

If you are looking for a staff attendance tracking system that has been customised for use within your industry, contact our sales team today.