FEIG Technology Supports Low Level Reader Protocol (LLRP)

Feig Electronics

FEIG ELECTRONIC, GmbH celebrated the 50th anniversary of its founding in 2016. As one of the few RFID suppliers offering LF, HF and UHF RFID readers to support each ISO Standard defined for passive RFID, the company’s long history with product development provides perspective on the paths that passive RFID products often follow through the market. It begins with the introductory release of a proprietary product; afterward, competing products enter the market. Early adopters embrace the new technology; however, price and incompatibility slows broader adoption. Standards begin to be developed, prices start to fall and larger available markets emerge. Passive UHF RFID followed this path, and it remains a very young technology compared to LF and HF standards that have existed for decades.

The Low Level Reader Protocol (LLRP) Standard, ratified by EPCglobal, Inc. in April 2007, is an application layer, message-oriented protocol that provides a standard interface between RFID Readers and Clients. By using the LLRP interface, the Client can retrieve Reader capabilities, retrieve and change Reader configuration, and control Reader operations. The latest version (v1.1) is more than six years old, having been published in October 2010.

The UHF Market is Surpassing LLRP

Consider the new and valuable UHF product features that have been released to the market since LLRP’s most recent release:

  • EPC GEN2V2 transponders add an encrypted security feature, the need for which was not considered at the time of EPC GEN2v1’s release.
  • NXP’s UCODE DNA, introduced in 2015, incorporates features even beyond GEN2V2. UCODE DNA implements all the mandatory commands of GS1 UHF RFID Gen2 v2.0, along with the following optional commands: Access, Authenticate, BlockPermalock, BlockWrite, ReadBuffer and Untraceable.
  • RF Micron’s Magnus S moisture and temperature sensor tags were introduced in 2015. While this tag uses standard GEN2V1 commands, it illustrates the market trend of further expanding functionality by offering environmental sensors with a passive RFID transponder, signaling a direction that is only anticipated to increase, driven by the Internet of Things (IoT).

Use of these latest transponder releases with LLRP requires expertise to understand the transponder’s operation at the bit level for the custom and proprietary commands to function. While it’s possible to execute custom commands over the LLRP interface, there are tradeoffs. Version 1.1 supports sending and receiving custom command strings across the air interface, but as a Reader to Client messaging protocol, commands are obviously sequenced individually.

Users that desire to keep pace with the latest features will be required to manage custom command strings as the transponder market continues to develop.

FEIG Helps These Technologies Operate Together Seamlessly

FEIG uses a single API across HF and UHF Reader products. This API has been developed over many years and exists in FEIG’s Multi-tag® reader operation. FEIG users are freed from the burden of understanding ISO commands and bit level complexities of transponders sourced from different manufacturers. Multi-tag® transparently performs the tasks necessary to operate a mixture of transponders within the same environment.

More importantly, FEIG’s Multi-tag® performs command sequencing within the architecture of the Reader’s firmware, providing significant increases in speed and performance when compared to executing a series of individual LLRP commands to achieve the same purpose.

Because UHF RFID will experience ongoing developments, FEIG chooses to implement support of LLRP through a windows application called ID FELLRP, which acts as a wrapper between the Low Level Reader Protocol and the Protocol of FEIG’s API. The methodology allows LLRP integration across FEIG’s i-scan UHF product line of Readers via USB interface or TCP/IP interface.


Implementing LLRP in this fashion maintains FEIG’s API and Multi-tag® operation. It avoids support of two native reader protocols, one of which is specific to only UHF operation, the other supporting both HF and UHF.

Using LLRP with FEIG Readers

For LLRP, the FEIG reader is preset to use FEIG’s ISO Start configuration program:

  • The Reader is placed in Buffered Read Mode (BRM)
    • BRM operates the Reader’s data collection function as a state machine with the Reader’s firmware. BRM provides the fastest execution times and data capture rates in comparison to a host-controlled Reader.
  • The frequency of operation is set for country of use.
    • FCC or EU frequency band and channel utilizations
  • The transponder Identification is set to “serial number”

Configuration of the following reader parameters may then be performed using LLRP. This includes configuration of:

  • Multiplexer Settings
  • Antenna output power
  • Transponder parameters
  • Filtering
  • I/O Settings
  • Trigger Conditions

Typical LLRP solutions available on the market include:

  • Long range readers with integrated Linux operating systems
  • Integration of the LLRP protocol directly on the reader
  • Support for only a TCP/IP interface
  • High-cost LLRP hardware

FEIG ELECTRONICS implementation of LLRP has these advantages:

  • A small application (ID FELLRP) running on the server
  • ID FELLRP can run as a local host directly on the server (IP=
  • ID FELLRP can also run on an external service
  • Support of variety of FEIG long range readers
  • Provides support of TCP/IP and USB readers
  • Supports low-cost readers such as FEIG MRU102
  • ID FELLRP is free of charge
  • Possible to install ID FELLRP directly on the LRU3x00 as a Linux application.

In this manner, FEIG maintains the structure of its reader firmware that optimizes data capture speed and performance. By comparison, typical LLRP implementations are unable to be optimized to any similar degree.

Perhaps a more significant user benefit of FEIG’s method of LLRP implementation is that new transponder releases can be immediately supported rather than waiting for the LLRP standard to be updated to accommodate new features released into the market. Examples include UCODE DNA and GEN2V2, which incorporate tag data security through encryption keys, in addition to an increasing trend to incorporate sensors into passive RFID tags.


FEIG Electronics, a leading global supplier of RFID readers and antennas, is one of the few suppliers worldwide offering RFID readers and antennas for all standard operating frequencies: LF (125 kHz), HF (13.56 MHz), UHF (860-960 MHz). A trusted pioneer in RFID with more than 40 years’ industry experience, FEIG delivers unrivalled data collection, authentication and identification solutions, as well as secure contactless payment systems. FEIG readers, available for plug-in, desktop and handheld applications, support next-generation contactless credit cards, debit cards, smartcards and NFC applications to enable fast, accurate, reliable and secure authentication and payment transactions.