RAIN RFID Alliance Releases Guideline for Simplified Reader Commands

The RAIN Communication Interface guideline provides a way for UHF RFID solution providers to build systems that can communicate with any make or model of reader and operate in multiple applications with different reader types, thus eliminating the need for APIs.
Published: October 22, 2018

The RAIN RFID Alliance has published its RAIN Communication Interface (RCI) guideline, intended to enable easier controls of RFID readers with simple JavaScript Object Notation (JSON) commands. The RCI guideline allows technology providers to offer systems that could operate with any reader, thereby enabling deployments with multiple reader types, as well as offering a solution that could be used at many customer sites. As billions of tags are deployed on products and assets that might move through multiple RFID reader infrastructures, the organization reports, the guideline will make it easier for each application to identify tags of interest, and to automatically disregard those the system does not recognize.

The guideline was created by members of the RAIN RFID Alliance’s Developers Workgroup after systems integrators asked for an easier way to control readers. RCI’s profile command replaces the need for a reader to send a series of commands to identify a tag and then process that tag’s response. Instead, the series of commands can be built into the single profile command. That function also eliminates the requirement for application programming interfaces (APIs) for each reader.

The guideline was first suggested in February 2016 at a Developers Workgroup meeting in Graz, Austria, says Steve Halliday, the RAIN RFID Alliance’s president. “One of our end-user members raised the prospect of having an easy way to talk to all of his readers,” he says, “no matter what brand they are.”

For end users and systems integrators, the challenge is to have a hardware-agnostic system that will operate with any make or model of UHF RFID reader. Traditionally, all reader manufacturers have provided their own proprietary command protocols and software APIs. For integrators, Halliday explains, that provides multiple challenges. “For example,” he says, “when installing readers at loading docks, for internal track-and-trace, and handhelds,” he says, the software of end users or integrators had to be programmed to control a variety of readers in a single deployment, and to accommodate additional readers as they were added.

“The same situation occurs when the integrator takes their software application and wants to re-use it for the next deployment,” Halliday says, and that end user specifies a different reader than the one the system already supports. In each case, systems integrators would then have to develop a custom solution for a deployment’s reader hardware, adding complexity and excess effort, and resulting in solutions that were more complex than they needed to be. In addition, inefficient and complex standard interfaces (or APIs) led the integrators to ignore some of the often-used features of the interfaces, and to ultimately develop their own reader interfaces, resulting in a lack of reader interoperability and support for all of the intended features.

The lack of a single interface protocol was a problem for large integrators that provide Internet of Things (IoT) services with many different systems being integrated, as well as for small system or service providers. This is especially true for scenarios in which small systems have the potential to become large and distributed, or be packaged into turnkey solutions for multiple deployments. “The RCI guideline helps everyone by reducing the need for RAIN air-interface protocol experts,” Halliday says, “which are scarce and, as such, are not available to the many smaller integrators.”

The JSON is a hierarchical set of field names and field values in a lightweight data-interchange format that is easy for humans to read and write. Using JSON, the RCI guideline specifies profiles with default field values which describe what a reader must do to inventory and access tags, such as performing additional reads or writes, or managing sensor and crypto functions. The guideline allows vendors to use fields in its default mode, so that they can build readers for dedicated purposes. “Such specific readers will typically use a much smaller set of fields,” Halliday notes. This, he explains, “makes it easier to develop with, deploy, and operate.”

The profiles can be used to create solutions in which specific commands are repeatedly carried out. For example, a retailer might not want to read tags on non-retail items. The application, therefore, can set up a profile to read only relevant GS1 EPC tags. Another example, Halliday says, is an application using vehicle tags for which the ISO data structure is used. In this case, the profile would be set up to read only the ISO vehicle tags, and to ignore all tags on retail items or vehicle parts.

The next guideline release is expected to provide data interpretation for sensor tags, and potentially for crypto tags as well. Future guidelines will provide interoperability with other protocols or communication standards, the workgroup reports. “RCI aims to provide the method for all RAIN applications to be good neighbors,” Halliday states. “Just imagine where the Web would be if webpage designers had to make different pages for different browsers.”

The RAIN RFID Alliance expects the guideline will be implemented by technology vendors. This, according to Halliday, will ultimately enable RFID technology to be used “from the grassroots, Raspberry Pi, hobbyist or students to the serious IoT and cloud service providers, and especially the integrators.”

The RCI Guideline can be downloaded at no cost at the RAIN RFID Alliance website.