[{"data":1,"prerenderedAt":205},["ShallowReactive",2],{"page:\u002Fresources\u002Frfid-singulation-s0-s1-s2-s3":3},{"id":4,"title":5,"approvalState":6,"body":7,"ctaDescription":190,"ctaLabel":190,"ctaTitle":190,"ctaTo":190,"description":191,"extension":192,"eyebrow":193,"heroImage":194,"heroImageAlt":195,"meta":196,"navigation":197,"path":198,"primaryCtaLabel":199,"primaryCtaTo":200,"seo":201,"stem":202,"summary":203,"__hash__":204},"pages\u002Fresources\u002Frfid-singulation-s0-s1-s2-s3.md","RFID singulation: S0 vs S1 vs S2 vs S3","internal-approved",{"type":8,"value":9,"toc":178},"minimark",[10,15,19,22,29,33,36,44,47,50,54,57,60,63,66,70,73,76,80,96,99,102,106,109,113,116,120],[11,12,14],"h2",{"id":13},"why-does-my-reader-find-most-items-but-miss-the-last-few","Why does my reader find most items but miss the last few?",[16,17,18],"p",{},"We saw this while scanning a rack of around 100 RFID-tagged garments. The labels were sewn into similar places, leaving tags close together and sometimes at a difficult angle to the handheld reader. Most garments appeared quickly. A few took repeated passes or even moving the garments before they appeared.",[16,20,21],{},"Changing the inventory session from S0 to S1 made it noticeably easier to finish the scan. To understand why, it helps to look at what happens inside the reader.",[16,23,24],{},[25,26,28],"a",{"href":27},"\u002Frfid-singulation-guide.pdf","Download the illustrated one-page guide (PDF)",[11,30,32],{"id":31},"what-singulation-does","What singulation does",[16,34,35],{},"Imagine writing down the names of everyone in a crowded room. If the same people keep calling out, quieter people may take longer to hear. Once you have someone's name, asking them to stay quiet briefly gives the others a chance.",[16,37,38,39,43],{},"An RFID reader has a similar job. It must identify individual tags among all the tags in range. After a tag has responded, its ",[40,41,42],"em",{},"inventory session"," affects how long it stays out of the next round of responses.",[45,46],"singulation-voices",{},[16,48,49],{},"Ledger can ignore duplicate reads after receiving them. That does not stop already-seen tags from taking part in the reader's radio conversation. The session setting acts earlier, while the reader is working through the tags.",[11,51,53],{"id":52},"s0-s1-s2-and-s3-compared","S0, S1, S2 and S3 compared",[16,55,56],{},"Each tag has a separate inventoried state for each of the four EPC UHF Gen2 sessions. These are separate settings, not four strength levels.",[58,59],"singulation-sessions",{},[16,61,62],{},"At normal operating temperatures, S1's state typically lasts 0.5 to 5 seconds. The standard gives S2 and S3 the same minimum persistence requirement after power is lost: more than 2 seconds. It does not rank S3 above S2.",[16,64,65],{},"These are useful starting points, not a guarantee of scan performance. Tag design, reader configuration, antenna position, materials nearby and the way items are packed all matter.",[11,67,69],{"id":68},"what-changed-on-the-garment-rack","What changed on the garment rack",[16,71,72],{},"With S0, the easier-to-read garments could become available again quickly. The remaining tags were tightly packed and often presented edge-on to the reader. With S1, tags already found stayed quiet for a short time, giving the harder-to-read tags more opportunities in later inventory rounds. Completing the rack became easier in our testing.",[16,74,75],{},"That does not mean a missed tag is always a session problem. If S1 still leaves gaps, move or separate the items, change the reader angle, and check for shielding, metal or poor tag placement.",[11,77,79],{"id":78},"which-session-should-i-use-in-ledger","Which session should I use in Ledger?",[16,81,82,83,87,88,91,92,95],{},"Ledger defaults to ",[84,85,86],"strong",{},"S1"," for Create, Allocate and Return, and ",[84,89,90],{},"S2"," for Inventory. Start with the setting shown in your workflow and test against your actual reader, tags and environment. If the same tag needs to trigger repeated reads in quick succession, try ",[84,93,94],{},"S0",". S2 and S3 can suit larger or more specialised scans, but neither is the universal choice.",[16,97,98],{},"You can change the session in Ledger's RFID settings and within individual workflows, so one setting does not have to cover every job.",[100,101],"singulation-ledger-settings",{},[11,103,105],{"id":104},"finding-one-known-tag","Finding one known tag",[16,107,108],{},"If you need to find one specific item, that is a different task from inventorying a whole group. On compatible Zebra readers, Ledger's Locate mode targets a known tag and shows a relative-distance bar as you move towards it. Locate mode is separate from the S0 to S3 inventory-session setting.",[11,110,112],{"id":111},"the-guide-at-a-glance","The guide at a glance",[114,115],"singulation-infographic",{},[11,117,119],{"id":118},"further-reading","Further reading",[121,122,123,132,139,146,153,159,165,171],"ul",{},[124,125,126],"li",{},[25,127,131],{"href":128,"rel":129},"https:\u002F\u002Fwww.gs1.org\u002Fstandards\u002Frfid\u002Fuhf-air-interface-protocol",[130],"nofollow","GS1 EPC UHF Gen2 Air Interface Protocol",[124,133,134],{},[25,135,138],{"href":136,"rel":137},"https:\u002F\u002Ftechdocs.zebra.com\u002Fdcs\u002Frfid\u002Fandroid\u002F2-0-3-162\u002Ftutorials\u002Fsingulation\u002F",[130],"Zebra singulation tutorial",[124,140,141],{},[25,142,145],{"href":143,"rel":144},"https:\u002F\u002Ftechdocs.zebra.com\u002Fdcs\u002Frfid\u002Fandroid\u002F4-0-0-9\u002Ftutorials\u002Frfiddevguide\u002F",[130],"Zebra tag locationing guide",[124,147,148],{},[25,149,152],{"href":150,"rel":151},"https:\u002F\u002Fsupport.impinj.com\u002Fhc\u002Fen-us\u002Farticles\u002F32153110595219-Impinj-IoT-Device-Interface-API-Example-Inventory-Configurations",[130],"Impinj inventory configuration examples",[124,154,155],{},[25,156,158],{"href":157},"\u002Fsolutions\u002Fissue-and-return","Ledger Issue and Return",[124,160,161],{},[25,162,164],{"href":163},"\u002Fsolutions\u002Fregister-and-deploy","Ledger Register and Deploy",[124,166,167],{},[25,168,170],{"href":169},"\u002Fcompatible-hardware","Compatible RFID hardware",[124,172,173],{},[25,174,177],{"href":175,"rel":176},"https:\u002F\u002Fdocs.ledgertech.app\u002Fmobile\u002Finfo-guides\u002Foperational.html#rfid-inventory-sessions",[130],"Change RFID sessions in Ledger Mobile",{"title":179,"searchDepth":180,"depth":180,"links":181},"",2,[182,183,184,185,186,187,188,189],{"id":13,"depth":180,"text":14},{"id":31,"depth":180,"text":32},{"id":52,"depth":180,"text":53},{"id":68,"depth":180,"text":69},{"id":78,"depth":180,"text":79},{"id":104,"depth":180,"text":105},{"id":111,"depth":180,"text":112},{"id":118,"depth":180,"text":119},null,"Why an RFID reader finds most tags but misses the last few. Learn how S0, S1, S2 and S3 inventory sessions affect scanning.","md","RFID guide","\u002Fgwc-set.jpg","Rows of graduation gowns hanging closely together in the GWC storehouse.",{},true,"\u002Fresources\u002Frfid-singulation-s0-s1-s2-s3","Explore resources","\u002Fresources",{"title":5,"description":191},"resources\u002Frfid-singulation-s0-s1-s2-s3","Why some RFID tags scan straight away while others seem to disappear, and what changing the inventory session can do.","pOiXalU3lM2CCAS_1xxl1L_rSwwOqd2QweNHPfUNHbI",1790666960950]