NDEF: Four letters defining the data exchange format in NFC !
NDEF stands for NFC Data Exchange Format it is a specification created by the NFC Forum which defines a common data format for devices and tags compliant with NFC Forum standards.
NDEF is a standardization norm for exchanges between two NFC devices, an NFC device and a tag. An NDEF tag can contain one or more messages called recordings. Each recording contains a header and in each header there is an identifier, a length and a type.
The NDEF also settles the rules for the creation of a valid NFC message. This specification establishes the rules for the recording of NFC messages.
Finally the NDEF specification defines the mechanism that allows you to precise which type of data from your application is encrypted in your NFC recordings.
The NDEF format is used to store and exchange informations, mostly URL’s or text thanks to a format widely understood and used. NFC tags like Mifare Classic cards can be configured as NDEF tags and data written on those cards by an NFC device can be understood and you can access it with any other device compliant with NDEF. NDEF messages can be exchanged in peer-to-peer mode between two NFC devices. By adhering to the NDEF data exchange format devices that don’t have knowledge of each other are able to share data in an organised and understandable manner for both devices.
The wide majority of NFC devices like readers, devices or tablets support the reading of NDEF messages coming from NFC tags. Every NDEF action type can be encoded on NFC chips by NFC readers. Because of the data size requirements or the memory size limitations depending on the NFC chip type it will be better to choose an NFC tags according to the type of data that you want to encode.
An NDEF recording has two components:
- A recording type to contextualise the payload data
- The Payload data
Together these two data represent actions to realise by the NFC devices when the NFC tag is touched. NDEF only supports a limited number of actions. More complex actions can be implemented by customising the software operating in the device.
As member of the NFC Forum we respect the NDEF for all of our readers.
Published on 12/04/2018