Impinj R700 Reader Modes (RF Modes)

Introduction and Other Resources

Reader modes (RF Modes) determine the configuration of the over-the-air data transmission between the antenna and the tag/endpoint of an Impinj reader.  The information in this article pertains specifically to the Impinj R700 RAIN RFID reader. General information on reader modes is available in the following linked article: Reader Modes Made Easy.

For help getting started in choosing reader modes for a particular use-case or application, see this article: What Reader Mode, Session, and Search Mode should I use for my application?

Overview

The Impinj R700 reader supports several different reader modes which allow the user to set the proper balance between the overall read rate, sensitivity, and the interference tolerance for a particular use case.

There are additional reader modes available on the Impinj R700 when compared to the LLRP modes discussed in the article referenced above. LLRP modes are also implemented on Impinj Speedway Revolution Readers, and are known by their mode index, or by names such as High Throughput, Hybrid, Dense Reader M4/M8, and Max Miller.

In addition to the static LLRP modes (LLRP modes 0-5) and AutoSet modes (LLRP modes 1002-1004), the Impinj R700 supports new static reader modes exclusively.  These new static reader modes are expressed by a 3-digit number to provide for a more granular configuration of a particular use case/environment. A subset of these new static reader modes map to existing LLRP modes and will be discussed further in the following sections.

LLRP Modes vs Static Reader Modes

The Impinj R700 LLRP modes map to a corresponding static reader mode implemented on the back end.  This mapping can be better understood through the following table:

LLRP to Static Reader Mode Mapping

LLRP Mode	FCC Static Reader Mode*	EU LB & Japan Static Reader Mode	EU HB Static Reader Mode	FGX Static Reader Mode**
Mode 0 - High Throughput	100	201	301	201
Mode 1 - Hybrid	120	221	322	221
Mode 2 - Dense Reader M4	142	240	340	243
Mode 3 - Dense Reader M8	185	284	381	284
Mode 4 - Max Miller	140	NA	341	NA
Mode 5 - Max Miller ETSI	NA	242	NA	242
Mode 1000 - Autoset	Not Supported	Not Supported	Not Supported	Not Supported
Mode 1002 - Autoset Dense Reader Deep Scan	1110 [100,140,142,185]	1210 [201,242,240,284]	1310 [301,341,340,381]	1213 [201,242,243,284]
Mode 1003 - Autoset Static Fast	1111 [100,140]	1211 [201,242]	1311 [301,341]	1211 [201,242]
Mode 1004 - Autoset Static Dense Reader	1112 [142,185]	1212 [240,284]	1312 [340,381]	1214 [243,284]

* Note: When the Impinj R700 FGX reader model is configured for FCC Operation, the reader has the modes shown in the "FCC Static Reader Mode" column of the table above.

**Note: When the Impinj R700 FGX reader model is not configured for FCC Operation, the reader has the modes shown in the "FGX Static Reader Mode" column of the table above.

We recommend the LLRP modes as a good starting point because the same LLRP mode numbers can be applied to multiple models and regions. The reader will automatically implement the selected LLRP mode with the appropriate static reader mode for the corresponding region/model.

In some cases, a particular static reader mode may offer a combination of read-rate, sensitivity, and interference tolerance that is better than an LLRP mode for a specific use case.  These are the situations in which the static reader mode selection can offer more granular options to specify reader behavior. The lower level Gen2 parameters for each static reader mode are shown in a later section of this article.

Reader Mode Examples and Data:

In the following section, we present graphs that show the throughput and measured sensitivity of the available reader modes.  It is important to note that these plots are specifically tested with a very large tag population in dual-target mode. The performance results shown for the FCC modes are collected from an Impinj R700 FGX reader model that is configured for FCC Operation. The first set of graphs below show the results with the LLRP modes (clicking on a graph will open it in a larger window, for easier viewing):

 

             Impinj R700 FCC LLRP Modes                                    Impinj R700 FGX LLRP Modes         

 

            Impinj R700 EU LB LLRP Modes                                 Impinj R700 EU HB LLRP Modes

       

 

             Impinj R700 Japan LLRP Modes                                 

The modes have been arranged in order (from left to right) from highest throughput to lowest.  Tracking the plots from left to right shows a general trend that as read-rate (dark blue) decreases, sensitivity (orange) increases (more negative is higher sensitivity), but there are a few minor exceptions.  

For LLRP modes, it is commonly seen that LLRP mode 0 (High Throughput) offers the highest read-rate with the lowest sensitivity, while LLRP Mode 3 (Dense Reader M8) offers the highest sensitivity and interference tolerance, but has the slowest read-rate.

We've also included graphs below to show the throughput and sensitivity results across various static reader modes (some are also underlying LLRP modes, but can be used as a comparison for the other static reader mode variations shown on the graph). They are arranged in the same way, as mentioned above, showing highest throughput to lowest (clicking on a graph will open it in a larger window, for easier viewing):

 

      Impinj R700 FCC Static Reader Modes                   Impinj R700 FGX Static Reader Modes

      

             

      Impinj R700 EU LB Static Reader Modes                 Impinj R700 HB Static Reader Modes

       

     Impinj R700 Japan Static Reader Modes

It is important to remember that we collected these results in a controlled specific test environment at Impinj.  Environmental conditions, tag population, tag type, antenna type, and other physical setup variables can affect the results of these tests.  We are providing the graphs here to show the general performance trends in regards to throughput and sensitivity, rather than the specific values/results. 

Impinj R700 Static Reader Modes

The Impinj R700 Reader includes static reader modes, that vary according to the reader model and region selected. The following tables list all the available static reader modes, as well as their corresponding modulation parameters:

Impinj Static Reader Modes FCC

Static Reader Modes	Fwd Modulation	TARI	PIE	BLF	M	DR
100	DSB-ASK	6.25	1.5	640	1	64/3
120	DSB-ASK	6.25	1.5	640	2	64/3
121	PR-ASK	14.29	1.5	320	2	64/3
122	PR-ASK	20	2	256	2	64/3
140	PR-ASK	7.14	1.5	640	4	64/3
141	PR-ASK	20	2	320	4	64/3
142	PR-ASK	20	2	256	4	64/3
180	PR-ASK	20	2	320	8	64/3
181	PR-ASK	20	2	256	8	64/3
184	DSB-ASK	6.25	1.5	160	8	8
185	PR-ASK	20	2	160	8	64/3

Note: When the Impinj R700 FGX reader model is configured for FCC Operation, the reader has the modes shown in the table above.

Impinj Static Reader Modes ETSI

Static Reader Modes	Fwd Modulation	TARI	PIE	BLF	M	DR
201	PR-ASK	14.29	2	320	1	64/3
221	PR-ASK	14.29	2	320	2	64/3
242	PR-ASK	14.29	2	426	4	64/3
240	PR-ASK	14.29	2	320	4	64/3
282	PR-ASK	14.29	2	320	8	64/3
283	PR-ASK	14.29	2	213	8	8
284	PR-ASK	14.29	2	160	8	8
301	PR-ASK	8.33	1.5	426	1	64/3
322	PR-ASK	8.33	1.5	426	2	64/3
341	PR-ASK	7.14	1.5	640	4	64/3
340	PR-ASK	7.14	1.5	320	4	8
380	PR-ASK	14.29	2	320	8	8
381	PR-ASK	14.29	2	160	8	8

 

Impinj Static Reader Modes Japan

Static Reader Modes	Fwd Modulation	TARI	PIE	BLF	M	DR
201	PR-ASK	14.29	2	320	1	64/3
221	PR-ASK	14.29	2	320	2	64/3
242	PR-ASK	14.29	2	426	4	64/3
240	PR-ASK	14.29	2	320	4	64/3
282	PR-ASK	14.29	2	320	8	64/3
283	PR-ASK	14.29	2	213	8	8
284	PR-ASK	14.29	2	160	8	8

 

Impinj Static Reader Modes FGX

Static Reader Modes	Fwd Modulation	TARI	PIE	BLF	M	DR
201	PR-ASK	14.29	2	320	1	64/3
221	PR-ASK	14.29	2	320	2	64/3
242	PR-ASK	14.29	2	426	4	64/3
243	PR-ASK	14.29	2	256	4	64/3
282	PR-ASK	14.29	2	320	8	64/3
283	PR-ASK	14.29	2	213	8	8
284	PR-ASK	14.29	2	160	8	8

Note: When the Impinj R700 FGX reader model is not configured for FCC Operation, the reader has the modes shown in the table above.

*BLF = Backscatter-Link Frequency
*M = Miller Encoding Number
* DR = Divide Ratio

Conclusion:

The information in this article should help to provide more understanding on both the LLRP modes and static reader modes available on the Impinj R700. The LLRP modes provide a good starting point, but in some particular use cases and environments, using a static reader mode may offer better performance.