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Impinj MultiReader Software



Impinj is announcing we will end availability of our MultiReader software in 90 days (July 2, 2018). On this date, it will no longer be available for download from the Impinj website and will not be supported by our support team. Additionally, we will not be releasing any new versions of MultiReader during the next 90 days. We recommend customers migrate or begin to use our ItemTest software, available for download here. We have also created a document to aid customers switching from MultiReader to ItemTest available for download here and on the ItemTest download page. If you have any questions please contact our Support team.


Impinj MultiReader software is provided by Impinj so that RFID systems can be set up for testing or demos without having to write custom reader software.  


Download Impinj MultiReader Software.

Download Impinj MultiReader Software & Release NotesDownload File


  • This article assumes you have successfully determined the IP address of your reader and are able to ping it over the network.
  • If the reader is running Speedway Connect or any other on-reader application, MultiReader software will not be able to connect to it. You will need to uninstall any on-reader application prior to starting MultiReader.


Configure Impinj MultiReader software for first-time use:

Prior to using MultiReader software, make sure you have your settings configured properly.  Here's how to do that:
  1. To start, connect to the Ethernet port of the reader.
  2. Launch MultiReader software.
  3. Click the "Configure Settings" button underneath the Impinj logo (or from the Menu, choose Settings -> Configure)
  4. On the Reader Settings screen, check and fill in the following:
    1. Ensure "Yes" is checked from the drop-down list next to "Control Reader".
    2. Enter the hostname or IP address of your reader in the box labeled "Name or IP Address". 
    3. Select your reader's Model from the drop-down list next to "Model".  If the box "Warn on model mismatch" is checked, you will receive a pop-up message when the reader you are connecting to does not match the model selection. 
    4. Select your operating region from the drop-down list next to "Operating Region".   
      NOTE: If you select the wrong model or operating region that does not match your reader, then MultiReader will either not work or give you unpredictable results.
    5. Choose "No" from the drop-down list next to "Antenna Hub Enabled" (for MultiReader version 6.6.4 and later)
  5. Next, click the "Modes, RF, Power" menu option under Reader 1 from the left side menu. Since we're just trying to establish that our reader can read tags, the defaults that are shown in this screen are fine. The screen-shot shows the FCC reader defaults. The important point here is to ensure that the check-boxes next to the antenna ports are enabled (place a check in the box to enable that antenna). Also, make sure the Tx Power setting is appropriate for your region.  You'll notice a change in this screen starting in MultiReader version 6.6.4 and later.  To enable/disable antennas and set Tx Power and Rx Sensitivity for each antenna, make sure you select the correct port number from the "Reader Antenna Port" portion of this screen.  Uncheck the box next to the word "Max" to set a specific value for Rx (receive) Sensitivity.

    For a more detailed explanation on the Search Mode and Session, please click here.
  6. Next, click the "Field of View" menu option under Reader 1 from the left side menu. The default for "Population Estimate" is 32. This should be fine for initial testing.
  7. Next, click the "GPI Triggers" menu option under Reader 1 from the left side menu. Ensure the "Triggering Enabled" is set to "Off".
  8. Next, click the "GPO Settings" menu option under Reader 1 from the left side menu. Ensure that all check boxes are empty.
  9. Next, click the "Filter" menu option under Display from the left side menu. Ensure "Filtering" is set to "Off".
  10. Next, click the "Run Mode" menu option from the left side menu. Ensure that "Run Mode" is set to "Single Inventory".
  11. Next, click the "Data Capture" menu option from the left side menu. Ensure that "Capture" is set to "On".
  12. Finally, click "Apply" at the bottom of the screen. If this is your first time running MultiReader, you will be prompted to Save Reader Settings. Choose where you would like to save these settings or accept the default location and click "Save".
    NOTE 1: The "Save Reader Settings..." pop-up is sometimes hidden behind the main MultiReader window, so be sure to check for it if you can't find it.  Remember, this window is only displayed once on the initial start-up of MultiReader or if you choose to reset the default settings in MultiReader.
    NOTE 2: You may also get the following "Save Reader Settings..." pop-up window asking you if you would like to save the configuration file in your directory instead of the default one.  Click "Yes".  Then, click "Save" on the subsequent pop-up window.
  13. MultiReader will send the configuration to your reader and now you will see the main screen with a green "START Inventory Run" button. Place at least one passive RFID (EPC C1G2) tag in the antenna's field of view. Click the green "START Inventory Run" button to start reading tags.


MultiReader doesn't work with my reader

Here are some things to try if MultiReader isn't able to connect to your reader:

  1. Check the Ethernet (CAT-5) cable to make sure you have a good connection to the reader.
  2. Make sure you're running the latest MultiReader software. The latest version is always available at the bottom of this post.
  3. Upgrade your reader to the latest firmware. Firmware images are available to Impinj Authorized Partners at this link.


 Read RFID Tags

  1. Launch the MultiReader application.  If you've configured MultiReader software to be used with your reader before (using the above steps), then you'll get the following pop-up window when you start MultiReader software:
  2. If you have successfully connected to your reader in the past and your setup has not changed, then you should be able to click "Yes" and you will be connected to your reader.
  3. Ensure you have an antenna connected to the reader and that this antenna is enabled through the MultiReader software (see prior section of this document for steps on how to do that). 
  4. Place some tags in the field of the attached reader antenna.
  5. Click the green "START Inventory Run" button.
  6. Tags will appear in the large main window. Tags that are being read will show up light yellow while tags that were read and are no longer in the antenna's field of view will show up red. Click the red "STOP Inventory Run" button.


Save RFID tag history

  1. MultiReader software will capture every tag read for each inventory run.  If you would like to save this information for further analysis, MultiReader software allows you to save the tag history to a .csv file which can be opened and viewed in Microsoft Excel.
  2. Ensure that Data Capture is "On" within the "Data Capture menu of the Reader Settings (see screenshot below).  Select "On" from the drop-down menu next to the word "Capture" (this is the default).

  3. Conduct a Single Inventory, Test Run, or Margin Test.  Start the inventory run by clicking the green "START Inventory Run" button (following the steps outlined above).  When you've finished reading tags, click the red "STOP Inventory Run" button.  The tags which you have read during this inventory run will be displayed on the screen as illustrated here:

  4. To save these tags and their associated data, click "File --> Save Tag History..." as shown in the screenshot below:
  5. On the subsequent "Save Inventory History Data" screen, fill in the TEST ID and TEST DESCRIPTION and click "OK".  The TEST ID will be included in the name of the file and the TEST DESCRIPTION will be included as notes in the .csv file.
    BEST PRACTICE NOTE: It is a good idea to include the details of which reader mode you used in this test, which antenna, number of tags expected, location of test, and anything else that you might be helpful about this test and the conditions of it.
  6. On the subsequent "Save Inventory History Data As..." screen, choose where you want to save the file, change the file name if you'd like, and click "Save".
    Note: Notice that the file name has the TEST ID as part of the name.
  7. Open the saved .csv file using Microsoft Excel.  Notice that the Test Description at the top of the file matches what you entered in the TEST DESCRIPTION field.
  8. The tag history fields are defined here:
    1. EPCValue = Tag EPC
    2. TimeStamp = Reader timestamp in Unix Epoch time.  Find out how to convert to a human readable timestamp by clicking here.
    3. RunNum = Run number; this is used when conducting multiple runs using the Run Mode "Test Runs".
    4. RSSI = Received signal strength indicator
    5. Reader = Reader that received the tag reads; this will either be '0' or '1'.  If '0', then this is reader 1 in MultiReader.  If '1', then this is reader 2 in MultiReader.
    6. Frequency = The specific frequency the reader was on when reading that particular tag value.
    7. Power = The specific reader transmit power for that tag to be read.
    8. Antenna = The antenna port that received the tag read.


Determine type of tag IC (e.g. Does this tag have a Monza chip inside?)

  1. If you want to determine the type of chip (integrated circuit or IC) that is inside an RFID tag, then MultiReader can help.
  2. Place a tag in the field of view of the reader's antenna.
  3. Launch MultiReader software.  Click the "Configure Settings" button and highlight "Modes, RF, Power".  Ensure "Search Mode" is set to "Dual Target".  Click "Apply".
  4. Click the green "START Inventory Run" button in MultiReader's main screen.  Once you see the tag show up on the MultiReader window, click the red "STOP Inventory Run" button.
  5. Leave the tag in the antenna field.
  6. Now, right-click on the tag EPC value.  You'll get the following menu:
  7. Click on "Tag Memory".
  8. The subsequent screen "Impinj MultiReader: Tag Memory Access" will be displayed as shown here:
  9. At the top of the screen, the Tag Memory (or IC, chip) will be displayed.  In this example, the tag has a Monza 4D chip inside.


Write (encode) a new EPC to the RFID tag

It's not an uncommon situation that a user connects to their Impinj Speedway Revolution reader, puts a number of tags in the read field, begins an inventory and sees that only one tag appears to be responding. "What's going on here?" is the typical response (along with maybe some head scratching). The answer usually lies in the fact that all the Monza tags come with the exact same Electronic Product Code (EPC) encoded to their memory at the factory. So, the reader will only report one tag in the read field because there is, in fact, only one unique EPC code being read. The procedure below will guide you through how to use MultiReader software to change the EPC code on the tags so that each one will be individually inventoried.

  1. Start the MultiReader application. Click on Configure Settings
  2. Enter reader IP, Model and Operating Region
  3. Click on Modes, RF, Power
  4. Enable antenna that will be in use
  5. Set the reader to AutoSet Dense Reader, Dual Target, Session 2
  6. Click on Run Mode and make sure it is set for Single Inventory
  7. Click Apply. Click "Save" if asked to save reader settings.
  8. Place the tags to be written in the read zone.
    NOTE: All of the tags with the same EPC will be written with this method.
  9. Click on [Start Inventory Run]. Let it read for a few seconds and click stop.
  10. Right click on the EPC value and choose Change EPC from the drop down menu

  11. Enter the new desired EPC value in the New EPC field.  Enter the number of tags to be written.  Click [Write Tags].
  12. You will get feedback on each tag written
  13. Click [Close] and read tags again by clicking on Start Inventory Run.
  14. Notice the new EPC values seen by the reader.

What if I wanted to change a group of tags that were in no particular order into a group of sequentially numbered tags?  You can also do this with MultiReader software.

  1. Let's take the following sample of random tag EPCs.
  2. Notice, that all of the EPC values start with 3008-33B2-DDD9 and then they are different after that.  You can easily change the EPCs on these tags so they are more meaningful and sequentially numbered. 
  3. Right-click on one of the EPC values and select Change EPC.
  4. Now, on the Change Tag EPC pop-up, use the wildcard character "X" to select more than just a single EPC.  For example, since all these tags start with 3008, then fill in the following for Current EPC: 3008-XXXX-XXXX-XXXX-XXXX-XXXX.  Fill in the new EPC value that you want to write to these tags.  Finally, fill in the number of tags you wish to write.  This is illustrated in the following screenshot:
  5. Click the "Write Tag(s)" button.
  6. You'll get feedback on the writing process.  Now, click "Close" and then re-inventory the tags by clicking on the "START Inventory Run" button.  Notice that all the tags have now been re-written so that they are in a sequential EPC order.

NOTE: If you are getting write errors during the process outlined above, the tags may not be getting enough power or they may be getting too much power.  Try again and either move the tags closer to the antenna or further away.  For example, if you're using the Impinj Mini-Guardrail antenna with the tags laying directly on the antenna, try moving them off the surface of the antenna by placing a small spacer between the tags and the antenna.


Conduct a Test Run or Margin Test

The Run Mode menu in MultiReader is designed to help you conduct testing using the Revolution reader with tagged items. The default option in Run Mode is Single Inventory.  This is the mode we've been using in the above instructions.  The Single Inventory mode is good for general tag reading and to determine if you're reading a tag in a particular spot or not.  However there are two other useful run modes.  One is called Test Runs and the other is Margin Test.

The "Test Runs" mode is designed to help you analyze tags moving through a portal.  This mode is good when conducting testing on your own since you can set a Start Delay, On Time, Off Time and Number of Runs. Once these are set, you are able to start the reader and it will automatically behave in the manner in which you set it. You can then carry out your testing without having to come back to MultiReader each time to start and stop the reader.  Turn on the sound and your PC will beep at you in between each run to give you an indication of when the next run begins.  Use the "Test Runs" mode when you want to conduct a series of tests like pushing a pallet of tagged items through a portal and recording which tags get read during each run.  The results are recorded on the main screen of MultiReader and you can save the details by following the directions above for saving tag history.

The third Run Mode option is the "Margin Test".  This test is conducted by placing tags in a static position (e.g. don't move them during this test) such as directly in the center of the portal.

In this mode you can configure a Start Power (not less than 10 dBm), End Power (up to 32.5 dBm), and Power Step (in increments of 0.25 dBm) as well as Start Delay, On Time, and Off Time. When you start the test, the reader will turn on at the start power level and incrementally step up by the configured Power Step setting until it reaches the End Power level. On the screen, you'll see the minimal power setting that is required to read the tag(s) in the read zone.

For example, in the above picture, it took 25 dBm of reader power to read the tag. If you are designing an RFID system, this test will tell you how much margin you have between what it takes to reliably read the tag (in this case 25 dBm) and the maximum power you're allowed to use (e.g. 30 dBm). For this example, you have 5 dBm of margin which is quite good. If this tag wasn't read until 29 dBm, then that would not be adequate margin and it would be better to redesign the system to ensure you're getting better margin.

The Margin Test is also useful for helping to "shape" your read zone.  For example, let's say you have tagged items staged nearby the portal that you don't want to read.  You can use the Margin Test to determine the transmit power and RSSI for those tags staged nearby.  If it takes less power to read those staged tags than it does to read tags in the portal (where you want to read them), then you're going to have to change the location of where you stage those items.  Otherwise, they will always be picked up by the portal and reported as leaving (or entering) that location.  If you are reading the "staged" tags but the RSSI is lower than tags being read in the zone, then you may be able to filter them out using RSSI filtering.  The Margin Test will help you determine whether or not you'll be able to make this work or not.


Collecting RDD Data with Impinj MultiReader software

If you report an issue to the Impinj Support Portal we may ask you to collect some data for us called an RDD (or Reader Debug Data) file. The RDD file contains important data that will help us determine what may be causing the issue you're having. The RDD file is not a text-based file, so you'll need to send it to us for analysis. It's important to point out that the RDD file can get large extremely fast, so try to capture the issue in the shortest time period as possible.

The process below will walk you through two ways of obtaining this file. Items required to perform these functions are:

  1. A network-connected Impinj Speedway Revolution reader
  2. A network-connected PC running MultiReader for Speedway Revolution

Method 1 – MultiReader controlling reader

  1. Start MultiReader and connect to the reader whose RDD you wish to capture. Once connected, click the Configure Settings button.
  2. Click on Data Capture and ensure the drop down menu next to Capture is set to On.
  3. Click "Apply" to send the configuration changes to the defined reader. Once complete, start an inventory run then stop the inventory run after 10 seconds.
  4. Click "File", then "Save Debug Data…"
  5. Type the name you wish to call the file (default is MultiReader.rdd) and select the folder you wish to save it to, then click "Save".


Method 2 – Another application controlling reader


  1. Start MultiReader and connect to the reader whose RDD you wish to capture. Once connected, click the Configure Settings button.
  2. Click on Data Capture and ensure the drop down menu next to Capture is set to "On".
  3. Click on Reader 1 and select the drop-down next to "Control Reader". Select "No", then click "Apply" and leave MultiReader running.
  4. Start and stop the reader using your own application. 
    NOTE: Since the RDD file can become quite large, start your application and let the reader run for the shortest amount of time necessary to capture the issue you're reporting.
  5. Go back into MultiReader and click "File", then "Save Debug Data…"
  6. Type the name you wish to call the file (default is MultiReader.rdd) and select the folder you wish to save it to, then click "Save".

Once either of the two methods described here has been performed, send the .rdd file to your Impinj support professional for analysis.





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Impinj (NASDAQ: PI) wirelessly connects billions of everyday items such as apparel, medical supplies, and automobile parts to consumer and business applications such as inventory management, patient safety, and asset tracking. The Impinj platform uses RAIN RFID, delivering information about items to the digital world and enabling the Internet of Things.