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1 Feb 2018, 13:33

The secret of NFC timing relay - why NFC technology is chosen over Bluetooth

What is NFC?

NFC works using electromagnetic induction between two coils, as discovered by Faraday's Law of induction.

NFC industrial applications

When NFC is put into application, there are 3 working modes in general:

  1. card emulation (e.g. smart phones for payment)
  2. reader/writer (e.g. read and write information on NFC tags)
  3. peer-to-peer (two NFC devices to communicate with each other).

For NFC timing relay, it works in the reader/writer mode, between NFC chip in Smartphone and passive NFC tag in the timing relay.

Why NFC is chosen for the next generation of Timing relay rather than Bluetooth?

Different from Bluetooth, NFC has very short range, depending on the type of NFC chip/tag chosen, it operates in a close proximity of 4cm while Bluetooth can reach 100 meters. It might seem that Bluetooth is superior in this angle, but both NFC and Bluetooth has their advantages and disadvantages.

Key parameters                       




4 cm

100 m

Data speed

424 Kbps

Up to 25 Mbps

Operating frequency

13.56 MHz


Power consumption

A few μW

0.01–0.50 W,

Up to 1W

Cost of the tag

Passive NFC Forum Tags around 0.1-0.5USD/pc



√ short range

x slower speed

x lower frequency

√ very low power consumption

√ much lower price

√ no need pair

√ longer range

√ fast speed

√ higher frequency

x higher power consumption

x very costly

x requires pairing


Short range

The short range proves to be an advantage in Timing relay application. It prevents interference to other unintended devices. Only the timing relay is within the range of NFC smartphone will be able to communicate(with in 4cm).  While Bluetooth will have trouble to send signal to the right timing relay when a number of timing relays are within the range(100m).

Extremely low power consumption

It is extremely low power consumption. The NFC tag embedded in the timing relay is passive data store that can be read and written to by the Smartphone APP.

 The meaning of “passive” is that it doesn’t require any battery or power. Passive NFC tags can be completely unpowered. When the active NFC chip come close, it will transmit some energy through electromagnetic force to the passive NFC tag to be activated. It works when the active NFC chip come close and transmit the energy to activate the passive NFC tag. Communication and dialog starts from there. 


It is very affordable. It costs less than 10% of the cost for Bluetooth chip.


Ease of use is another advantage NFC technology has compared to Bluetooth. NFC connects automatically in a few seconds, while Bluetooth requires users to pair between smartphone and devices, it takes much longer and additional manual steps. NFC is faster and easier.


As a summary

Wireless, short range, low power consumption and battery-less, affordability, easy & fast, all these features make NFC a perfect solution to revamp the total user experience on an industrial device like timing relay.

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1 Feb 2018, 13:33