xArray Gateway - Frequently Asked Questions (FAQ)

Q: Where can I purchase an xArray?

Please visit http://www.impinj.com/where-to-buy/  to find an xArray Certified Partner.


Q: What are the ideal and max heights for mounting the xArray device?

xArray provides the best performance and coverage area when mounted at heights from 10 feet to 15 feet. A site survey that evaluates the RF characteristics of the environment and the choice of tags is recommended to determine the optimal mounting height. Best results will be achieved with tags that use Impinj Monza R6 chips.


Q: What is difference between the 1,500 ft range and Real Time Location of 1.5 meters discussed for xArray? 

1,500 square feet is the floor coverage area that xArray can monitor. Real-time location refers to xArray’s ability to pinpoint location of an item to within 1.5 meters (~5 feet) of the item’s actual location.


Q: Do xArrays require a calibration process during the setup phase? 

xArray gateways can begin reading tags out of the box. They do not require calibration, but the xArray is highly configurable and tunable to work optimally in a given environment.


Q: Could you describe the concept of the 52 beams?  Is this a calculated number?

The xArray gateway includes a sophisticated antenna array and is able to distinguish between 52 different beam states. A diagram on the xArray datasheet shows the 52 zones that xArray identifies on x,y coordinates.


Q: How fast does xArray scan the 52 beams?

Scan time for all 52 beams can take a few seconds up to several minutes depending on the number of tags in the field of view and the mode that the xArray is operating in.


Q: How does the xArray do the mapping / conversion of x,y to logical zone / location? 

After identifying a 0,0 location point for a facility, each xArray establishes a x,y coordinate in relation to the 0,0 point it is mapped to. A software layer on top of the xArray can take these coordinates to create zones that you specify.


Q: Can the xArray reader capture motion of tags through the field?



Q: Does xArray require special software?

xArray gateways can begin reading tags out of the box using Impinj’s ItemTest software but additional software is typically required for enterprise deployments. ItemTest software allows for quick tests of xArray features and capabilities.


Q: Does xArray use LLRP protocol and/or Octane SDK?

Yes to both. xArray uses LLRP and Octane SDK fully supports the new features and user modes introduced by xArray.


Q: How does the xArray cope with multiple metal shelves (racking)?

Metal can certainly block line-of-sight of RF waves, though metal shelves can also improve tag readability due to their ability to reflect RF waves and allow the signal to get to hard-to-reach areas. Site surveys are recommended for environments which contain a lot of metal.


Q: Does the RF bounce in high metal environment impact the accuracy of the location sensing capabilities?

Yes, metal will impact the location-sensing ability of the xArray. A site survey by an Impinj xArray Certified Partner is recommended.


Q: Does the floor coating (e.g., carpet vs. marble) effect performance of xArray?

Floor coating should not adversely affect the xArray performance.


Q: If you mount the xArray on a wall looking forward, what distance will you get?

xArray is calibrated to meet the FCC mandated limit of 36 dBm EIRP. It will perform similarly to a Speedway Revolution reader with an off –the-shelf antenna when mounted in this fashion.


Q: Is the data output from xArray limited to the x-y coordinates or can it also provide z (height)?

xArray’s Location User modes provides x-y coordinates based on the height of the xArray with respect to the tag location. Elevation and Azimuth for the tag can be computed from the x-y coordinates but requires similar information to come from a different xArray to try to use triangulation to infer the height of the tag.


Q: What happens when there are walls in between the xArray and the tags?

Depending on the make-up of the wall, it may be possible to read through it with a xArray as can happen with other reader and antenna combinations. We do not recommend relying on the ability to read through walls to solve a use case. Shielding materials are also available to prevent reading of unwanted areas.


Q: When x/y events are translated to zone events by the agent software, does one xArray serve as a "master" to coordinate the data from multiple xArrays located close to each other?

No, each xArray works independently and is not aware of other xArrays sharing the same space. An xArray gateway is not able to receive information coming from other xArrays.


Q: Does xArray only work with specific Impinj tags, or does it work with other tags?

xArray supports all RAIN RFID tags however best performance is achieved with tags built on the Impinj Monza R6. This video highlights why tag chip selection matters: https://support.impinj.com/hc/en-us/articles/204244013-xArray-Gateways-Why-Tag-Selection-Matters-VIDEO-


Q: What is tag integration cost per product (shirt/tool/etc) to support xArray?

Tag prices are dependent on a number of factors including chip, form factor, volume, etc. Please contact a tag or inlay provider to determine pricing for the tag that meets your needs.


Q: How many tags can be read at the same time by each xArray?

xArray can achieve throughput of about 1,000 tags per second.


Q: Does tag orientation affect read range?

xArray provides excellent area coverage, always-on monitoring, and software to help it find even difficult to reach tags. Tag orientation can and will impact performance but xArray is designed with dual linearly polarized beams to minimize tag orientation effects.


Q: What size Tags/Inlays were used for the 1,500sq feet test?

This test was performed using 70mm by 14.5mm inlays.


Q: Is there a need for Site Surveys before installation?

Yes, A site survey and knowledge of RFID is recommended for a successful deployment. All xArray Certified Partners have been trained to understand xArray installation requirements.


Q: Are videos of best practices available?

 Yes, we are continuing to develop content to support xArray solution developers. Please visit http://support.impinj.com.


Q: Where can I find information about xArray IP rating, temperature rating, etc.?

 Please see the xArray datasheet at http://support.impinj.com.


Q: How can I optimize the accuracy of the location algorithm used by the xArray Gateway?

The most effective way to optimize the location accuracy is to increase the number of tag reads by:

  • Using a high-performing RAIN RFID tag such as those utilizing Monza R6 tag chip.
  • Use the maximum tag throughput Reader Mode setting such as the default ‘Max Throughput’ (Mode 0) on the xArray Gateway.
  • Ensure each tag is seen by at least 2 xArray Gateways and use a weighted averaging algorithm – you can discuss with a certified xArray Partner to learn more.
  • Configure adjacent xArrays for different Session settings (i.e. one for ‘Session 2’ the adjacent for ‘Session 3’)


Q: Is the xArray Gateway an Electronic Article Surveillance (EAS) device?

While the xArray Gateway provides inventory information, which can be useful when deployed as part of an overall EAS strategy (along with Point-of-Sale data and EAS Detection Gates), it is not meant to be a stand-alone EAS device.


Q: How can I optimize inventory of tagged items using xArray Gateway in Wide Area Monitoring (WAM) mode?

The most effective way to optimize inventory of tagged items is to utilize tag suppression, specifically ‘Tag Focus’ mode if using Impinj Monza tag chips.


Q: Do Impinj Gateways come preloaded with the software that makes them function or does software need to be installed after purchase?

Impinj preinstalls all of its Gateways with a supported version of Impinj firmware called Octane.  Application software using an Impinj provided library allows the gateway to programmatically function to meet the need of the end user’s application.


Q: Do xArray Gateways function differently depending on the region or geography for which it is deployed? 

xArray Gateways are available in various different regions. In each case the gateways operate in the frequencies to meet the specific rules of that region or geography. 


Q: What regulatory standards and regions are Impinj Gateways certified?

The latest, up to date list can be found on https://support.impinj.com/hc/en-us/articles/218903917-Supported-Regions-and-Geographies


Q: How far from an xArray gateway can a RAIN RFID tag be read?

The readable distance from the xArray Gateway is dependent on the tag chip, tag Inlay, and item that the tag is placed on.  The more sensitive the tag chip, for example, the longer the read distance.  Also, larger tag inlays tend to be readable from a greater distance. xArray installed overhead are typically spaced about 20 feet or 6 meters apart to provide RAIN RFID coverage throughout the space.  We advise you to contact your tag inlay manufacture for recommendation regarding the proper tag to use for the intended use case.


Q: Is there a limit to how old a tag can be to still be read by an xArray Gateway?

RAIN RFID tags are passive, meaning that no battery is required to energize the tag however tag inlays vary in durability.  We advise you to contact your tag inlay manufacture for specifics on their tag’s life expectancy.


Q: Will the xArray Gateway provide the necessary environmental protection to operate outdoors or in a harsh environment?

xArray Gateways are designed to operate in a dry temperature controlled environments Gateways have an IP 50 rating.  Operating in a harsh environment will require an enclosure that does not interfere with the RF signals.  At this time, Impinj does not provide any recommendation on specific enclosures. Also, keep in mind that the gateway’s operating temperature range of -20C to 50C.


Q: Besides temperature and moisture, what environmental restrictions should be considered when installing an xArray Gateway?

The xArray Gateway needs to be installed in a space where the RF signals are not blocked by nearby (within a few feet) metal or lighting.


Q: Are xArray Gateways able to send and receive encrypted data?

Yes, all Impinj Gateway can send and receive encrypted data over a secure LLRP connection. 


Q: Are xArray Gateways able to send and receive compressed data?

No, all Impinj Gateways use the LLRP protocol which is not compressed.


Q: How are security patches provided for the xArray Gateway?

 Security patches if needed are typically provided during the release of a new Octane firmware version.


Q: How are xArray gateways monitored for security violations and system health?

 Impinj Gateway capture all detected exceptions including security and system errors to a syslog which the user has access to.


Q: What tools are available to developers writing application for an Impinj xArray Gateway?

Impinj offers an object-oriented library called Octane SDK which provides both Java and .NET

developers an easy-to-use API to control and collect data from all Impinj Gateway products.


Q: What development environments are supported by Octane SDK?

Octane SDK is compatible with a wide set of software development environments including:  Microsoft Visual Studio for .NET developers and Eclipse, IntelliJ, and NetBeans for Java developers. 


Q: What software architectures can be implemented using Octane SDK?

Over the years a board range of software architectures have been implemented ranging from on-reader applications, desktop applications that communicate with the gateway, middleware applications that communicate between the gateway and an ERP system, and cloud applications that collect data sent from a gateway.

Was this article helpful?
4 out of 4 found this helpful



Article is closed for comments.