With the spread of wireless connectivity solutions and the proliferation of smartphones with these connectivity solutions, one technology that constantly gets evaluated for its innovative use is Near Field Communication (NFC).
Applications in the field of automotive, medical, health and fitness, wearables, IoT, consumer electronics and industrial space continue to integrate NFC. By one estimate, the shipment of NFC ICs is forecasted to reach one billion units by 2018.
NFC has several unique characteristics that lend it for consideration in new and innovative use cases and brings with it great ease of use and convenience to the many applications it serves. There are over 500 million NFC enabled devices in existence today supporting a large number of varied applications and the infrastructure continues to expand becoming more robust with new end equipment and manufactures joining this.
What is NFC?
NFC is a short range bi-directional wireless communication technology developed from the legacy High Frequency (HF) Radio Frequency Identification (RFID) contactless card standards. NFC adds additional operating modes to existing RFID standards. It operates at 13.56 MHz and provides read range of a few centimeters which provides a dedicated read zone and inherent security for the applications it serves. ISO14443A/B, ISO15693 are some of the key data communication protocols for NFC. The NFC forum, an industry organization for NFC technology, specifies three operating modes for NFC devices:
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Peer-to-Peer: This mode provides a communication mode between two devices where both devices are able to initiate communication when required.
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Reader/writer: In this mode an NFC device has the ability to read data from and write data to NFC/RFID tags and contactless smartcards.
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Card Emulation: In this mode an NFC device behaves like a tag or a contactless smartcard
Depending on the operating modes supported, NFC ICs are broadly classified as:
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Tags also called transponders: Devices that store data. Tags can be active or passive depending on whether they are actively powered or not. They can also be classified as static or dynamic depending on how the data stored is updated – programmed once or dynamically updated. Dual interface dynamic tags allow a host controller (connected over SPI or I2C) to update data in the tag memory which can then be read over the NFC interface.
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Reader/writer: Devices that read from or write to the tags over the air using NFC interface. Reader/writer device initiates the RF communication to the tag and generates the electromagnetic field that tag load modulates with data.
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NFC devices: Transceiver ICs that support all three operating modes – Reader/Writer, Peer-to-Peer and Card Emulation as specified by the NFC Forum.
NFC can add convenience and ease of use in many consumer electronics, medical, health and fitness and IoT applications. So while the scope of NFC technology is not limited to industrial applications this article focuses on identifying some use cases for this technology in the industrial segment.
Enabling a Broad Range of Industrial Applications
Applications in the industrial segment can greatly benefit from the key characteristics of NFC – wireless connectivity, low power consumption, capability for passive (battery-less) operation and security. By one industry estimate, shipment of NFC ICs in this segment is forecasted to exceed 200 million units by 2018.
Pairing nodes to gateway: In a connected industrial environment there are many devices (nodes) connected to one another though a central gateway over Bluetooth®, Wi-Fi, 802.15.4, Zigbee etc. NFC can allow secure and convenient pairing of these devices with a simple tap. An NFC tag embedded in a node can pass the configuration settings to a reader on a smartphone or a gateway to easily pair them together. As the number of nodes increase in a system, the complexity of pairing them can be simplified using NFC.
Service Interface: NFC devices can act as a bidirectional conduit for data in and out of industrial equipment. A dual interface dynamic transponder can receive data from an NFC enabled device (eg. smartphones, tablets) wirelessly and pass it to an embedded host controller over I2C/SPI or another digital interface. This implementation can be used for firmware updates, maintenance and retrieving diagnostic data while eliminating wires and the need for dedicated terminal screens on the equipment, thereby reducing cost.
Access Control: Utilizing its close proximity based secure connectivity, NFC/RFID tags and reader/writer devices can be used for access control. NFC reader devices can be embedded in equipment or specific areas of a facility to control and log access from authorized personnel who can use their RFID cards or NFC enabled phones to gain access.
Product Authentication and Asset Tracking: NFC tags can be embedded in equipment to prevent counterfeiting and also for asset tracking. Data stored on the NFC tag can be encrypted using the unique identifier (UID) of the tag.
Wireless sensors: NFC tags can enable wireless sensor applications, where the NFC interface can be used not only for data transfer but also for powering sensors by harvesting energy from the RF field of the reader. One such application is hermetically sealed (air-tight) glass encapsulated sensor nodes. Encapsulation allows operating in harsh operating conditions and NFC provides wireless connectivity and passive (battery-less) operation. Even in the case of battery-powered nodes, extended battery life is desirable; low power consumption feature of NFC can enable that.
Remote sensor networks: NFC when coupled with Bluetooth® or Wi-Fi can be used to create remote sensor networks where nodes can be easily paired/provisioned within the network using NFC to allow simple tap and connect. Also NFC interface can be used to access data from individual nodes using an NFC reader device such as a smartphone.
Design Considerations for Developers
Primary concerns for developers of such applications are power consumption, availability of non-volatile memory for data storage and cost of bundling multiple features that enable these applications. Other important factors are read range, development effort, implementation cost and security of data communication.
Texas Instruments NFC Portfolio
Texas Instruments has a broad NFC portfolio that includes devices from all three categories. It includes passive (Tag-itTM) and dual interface dynamic NFC transponder ICs (RF430CL330H), highly integrated NFC sensor transponder IC (RF430FRL152H), NFC reader/writer ICs (TRF7960A) and NFC Device transceiver ICs (TRF7970A).
TI NFC products provide robust RF performance while delivering on ultra-low power requirements. NFC transponder and transceiver devices have several low power modes to minimize current consumption during active and standby mode for extended battery life. Wake up on RF detect feature on these devices allows developers to create designs that remain in low power state until an RF field is detected.
TRF7970A is a full featured NFC transceiver that supports all three NFC operating modes: Peer-to-peer, card emulation and reader/writer. It is a highly integrated multi-protocol (ISO14443A/B, ISO15693) NFC device that is designed to achieve ultra-low power performance and is supported by the NFCLink firmware library which enables easy porting of NCI functions on a variety of embedded host processors.
Recently launched RF430FRL152H NFC sensor transponder includes FRAM (non-volatile) memory for data storage and provides a highly integrated solution with a programmable MCU for sensor applications that require NFC (ISO15693) connectivity. It is designed to provide an easy to use single chip solution that reduces BOM cost and developments effort for developers.
TI provides great resources to get developers started on their designs. TI Designs is a library of reference designs that lets users begin their designs using resources that TI has already out together.