{"product_id":"honeywell-900c51-0021-programmable-logic-controller","title":"Honeywell 900C51-0021 PLC Controller","description":"\u003cstyle\u003e.shly-pdp{--ink:#1c2024;--muted:#5b6570;--line:#dfe3e8;--bg:#fff;--soft:#f6f7f9;--accent:#C8102E;max-width:1000px;margin:0 auto;padding:4px 0 32px;color:var(--ink);font-family:-apple-system,\"Segoe UI\",Roboto,Helvetica,Arial,sans-serif;line-height:1.62;font-size:15.5px;-webkit-text-size-adjust:100%;}\n.shly-pdp *{box-sizing:border-box;}\n.shly-pdp h3{font-size:17px;font-weight:700;margin:34px 0 12px;padding:0 0 8px;border-bottom:1px solid var(--line);letter-spacing:.2px;}\n.shly-pdp p{margin:0 0 12px;}\n.shly-pdp .shly-eyebrow{font-size:11.5px;letter-spacing:1.6px;text-transform:uppercase;color:var(--accent);font-weight:700;margin:0 0 8px;}\n.shly-pdp .shly-lead{font-size:16.5px;line-height:1.68;color:#2b3138;margin:0 0 4px;}\n.shly-pdp .shly-lead b{font-weight:700;}\n.shly-pdp .shly-facts{list-style:none;margin:14px 0 0;padding:0;display:grid;grid-template-columns:repeat(4,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:6px;overflow:hidden;}\n.shly-pdp .shly-facts li{background:var(--soft);padding:12px 14px;font-size:13.5px;line-height:1.45;}\n.shly-pdp .shly-facts span{display:block;font-size:11px;text-transform:uppercase;letter-spacing:.9px;color:var(--muted);margin-bottom:4px;}\n.shly-pdp .shly-facts strong{font-weight:700;font-size:14.5px;}\n.shly-pdp table{width:100%;border-collapse:collapse;margin:6px 0 10px;font-size:14.5px;table-layout:fixed;}\n.shly-pdp th,.shly-pdp td{text-align:left;vertical-align:top;padding:9px 12px;border-bottom:1px solid var(--line);word-break:break-word;}\n.shly-pdp th{width:38%;font-weight:600;color:#333a41;background:#fafbfc;}\n.shly-pdp tr.shly-group td{background:#eef1f4;font-size:11.5px;letter-spacing:1.3px;text-transform:uppercase;font-weight:700;color:#48525c;padding:7px 12px;}\n.shly-pdp .shly-note{font-size:13.5px;color:var(--muted);border-left:3px solid var(--line);padding:2px 0 2px 12px;margin:10px 0 0;}\n.shly-pdp ul.shly-list{margin:8px 0 0;padding:0 0 0 20px;}\n.shly-pdp ul.shly-list li{margin:0 0 8px;}\n.shly-pdp .shly-q{border-top:1px solid var(--line);padding:14px 0 2px;}\n.shly-pdp .shly-q:first-of-type{border-top:none;}\n.shly-pdp .shly-q p{margin:0 0 6px;}\n.shly-pdp .shly-q .shly-qq{font-weight:700;color:#1c2024;}\n.shly-pdp .shly-q .shly-qq em{font-style:normal;color:var(--accent);margin-right:6px;}\n@media (max-width:720px){\n.shly-pdp{font-size:15px;}\n.shly-pdp .shly-facts{grid-template-columns:repeat(2,1fr);}\n.shly-pdp th,.shly-pdp td{padding:8px 10px;font-size:14px;}\n.shly-pdp th{width:42%;}\n}\u003c\/style\u003e\u003cdiv class=\"shly-pdp\"\u003e\n\u003cp class=\"shly-eyebrow\"\u003eHoneywell · PLC controller\u003c\/p\u003e\n\u003cp class=\"shly-lead\"\u003e\u003cb\u003e900C51-0021\u003c\/b\u003e is a Honeywell PLC controller with Total I\/O Up to 4608 with remote I\/O; Supply voltage 24 V DC (IEC 61131-2); Enclosure rating IP20 (IEC 60529). It is used in packaging machines, conveyor transfer cells, small process skids where the installed unit is matched to the original catalog number and a compact, documented part is required.\u003c\/p\u003e\n\u003cul class=\"shly-facts\"\u003e\n\u003cli\u003e\n\u003cspan\u003eTotal I\/O\u003c\/span\u003e\u003cstrong\u003eUp to 4608 with remote I\/O\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eSupply voltage\u003c\/span\u003e\u003cstrong\u003e24 V DC (IEC 61131-2)\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eEnclosure rating\u003c\/span\u003e\u003cstrong\u003eIP20 (IEC 60529)\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eCommunication ports\u003c\/span\u003e\u003cstrong\u003e1 Ethernet port, 10\/100 Mbps\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctr class=\"shly-group\"\u003e\u003ctd colspan=\"2\"\u003eElectrical\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSupply voltage\u003c\/th\u003e\n\u003ctd\u003e24 V DC (IEC 61131-2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"shly-group\"\u003e\u003ctd colspan=\"2\"\u003eI\/O and communication\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCommunication ports\u003c\/th\u003e\n\u003ctd\u003e1 Ethernet port, 10\/100 Mbps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTotal I\/O\u003c\/th\u003e\n\u003ctd\u003eUp to 4608 with remote I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"shly-group\"\u003e\u003ctd colspan=\"2\"\u003eMechanical\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDimensions (H x W x D)\u003c\/th\u003e\n\u003ctd\u003e137 mm x 38.1 mm (5.4 in x 1.5 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003e360 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMounting\u003c\/th\u003e\n\u003ctd\u003e35 mm DIN rail (IEC 60715)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEnclosure rating\u003c\/th\u003e\n\u003ctd\u003eIP20 (IEC 60529)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"shly-group\"\u003e\u003ctd colspan=\"2\"\u003eEnvironment and compliance\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOperating temperature\u003c\/th\u003e\n\u003ctd\u003e0...+55 °C (IEC 60068-2-1)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCertifications\u003c\/th\u003e\n\u003ctd\u003eCE, cULus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cp class=\"shly-note\"\u003eValues follow the Honeywell PLC controller specification for this catalog number; parameters not confirmed for this variant are omitted rather than estimated.\u003c\/p\u003e\n\u003ch3\u003eModel comparison in the same family\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctr class=\"shly-group\"\u003e\u003ctd colspan=\"4\"\u003eHoneywell PLC controller variants\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"width:26%\"\u003eCatalog number\u003c\/th\u003e\n\u003cth style=\"width:24%\"\u003eTotal I\/O\u003c\/th\u003e\n\u003cth style=\"width:24%\"\u003eSupply voltage\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cb\u003e900C51-0021\u003c\/b\u003e (this page)\u003c\/td\u003e\n\u003ctd\u003eUp to 4608 with remote I\/O\u003c\/td\u003e\n\u003ctd\u003e24 V DC (IEC 61131-2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/honeywell-900c51-0011-programmable-logic-controller\"\u003e900C51-0011\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 4608 with remote I\/O\u003c\/td\u003e\n\u003ctd\u003e24 V DC (IEC 61131-2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/honeywell-900c51024300-programmable-logic-controller\"\u003e900C51024300\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 4608 with remote I\/O\u003c\/td\u003e\n\u003ctd\u003e24 V DC (IEC 61131-2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/honeywell-900c50036000-programmable-logic-controller\"\u003e900C50036000\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 4608 with remote I\/O\u003c\/td\u003e\n\u003ctd\u003e24 V DC (IEC 61131-2)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cp class=\"shly-note\"\u003eBefore selecting an alternative, confirm its dimensions, terminals and installation requirements in the manufacturer documentation.\u003c\/p\u003e\n\u003ch3\u003eWhere it sits in the control system\u003c\/h3\u003e\n\u003cp\u003eThe 900C51-0021 is the device-level element in a Honeywell PLC controller installation. It receives the field signals and control supply listed above — 24 V DC (IEC 61131-2) — and switches or conditions the load within the the rated ratings shown in the Specifications table. Wiring and protective devices are sized to those same numbers, not to a generic assumption.\u003c\/p\u003e\n\u003cp\u003eTypical installations place it in packaging machines, conveyor transfer cells, small process skids, where the unit is matched to the original catalog number and the enclosure provides 35 mm DIN rail (IEC 60715) support. Record the catalog number and revision from the nameplate of the installed unit before specifying a like-for-like spare.\u003c\/p\u003e\n\u003ch3\u003eSelection notes for Honeywell 900C51-0021\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eHoneywell 900C51-0021\u003c\/strong\u003e — PLC \/ CPU module used as the device-level control core in an automation panel, handling logic, timing and communication tasks. The figures below are taken from the specification table on this page for catalog number 900C51-0021; verify the catalog number against your bill of materials before requesting a quotation.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDimensions (H x W x D): \u003cstrong\u003e137 mm x 38.1 mm (5.4 in x 1.5 in)\u003c\/strong\u003e — Match it to the existing panel and upstream protection.\u003c\/li\u003e\n\u003cli\u003eCertifications: \u003cstrong\u003eCE, cULus\u003c\/strong\u003e — Record it with the other nameplate data when sourcing a replacement.\u003c\/li\u003e\n\u003cli\u003eSupply voltage: \u003cstrong\u003e24 V DC (IEC 61131-2)\u003c\/strong\u003e — Confirm the revision of the installed unit before a like-for-like replacement.\u003c\/li\u003e\n\u003cli\u003eWeight: \u003cstrong\u003e360 g\u003c\/strong\u003e — Use it as the reference when cross-checking a current-production equivalent.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCross-check the ratings above with the installed device before confirming the order.\u003c\/p\u003e\n\n\u003ch3\u003eCommon questions about 900C51-0021\u003c\/h3\u003e\n\u003cdiv class=\"shly-q\"\u003e\n\u003cp class=\"shly-qq\"\u003e\u003cem\u003eQ.\u003c\/em\u003eWhich value is published under communication ports for catalog number 900C51-0021?\u003c\/p\u003e\n\u003cp\u003eFor 900C51-0021, communication ports is given as 1 Ethernet port, 10\/100 Mbps. Compare it with the nameplate of the installed unit before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"shly-q\"\u003e\n\u003cp class=\"shly-qq\"\u003e\u003cem\u003eQ.\u003c\/em\u003eBefore ordering 900C51-0021, which mounting entry should be checked?\u003c\/p\u003e\n\u003cp\u003eThe mounting entry quoted above is 35 mm DIN rail (IEC 60715). Confirm this figure against the unit currently in the panel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"shly-q\"\u003e\n\u003cp class=\"shly-qq\"\u003e\u003cem\u003eQ.\u003c\/em\u003eWhere can I find the certifications data for 900C51-0021?\u003c\/p\u003e\n\u003cp\u003eIt is listed in the specification table for Honeywell 900C51-0021 as CE, cULus. Use the value as the reference when sourcing a current-production equivalent.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"shly-q\"\u003e\n\u003cp class=\"shly-qq\"\u003e\u003cem\u003eQ.\u003c\/em\u003eCan the 900C51-0021 replace the unit currently installed in my panel?\u003c\/p\u003e\n\u003cp\u003eCompare catalog number 900C51-0021 and the ratings above with the nameplate of the installed device. A current-production equivalent is selected by function and electrical rating, not by the label alone.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"shly-q\"\u003e\n\u003cp class=\"shly-qq\"\u003e\u003cem\u003eQ.\u003c\/em\u003eHow do I confirm compatibility of 900C51-0021 before ordering?\u003c\/p\u003e\n\u003cp\u003eMatch the catalog number 900C51-0021 and the specification values listed above against the installed unit, then confirm the firmware or hardware revision where a revision-sensitive part is involved.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Honeywell","offers":[{"title":"Default Title","offer_id":71134641324285,"sku":"900C51-0021","price":4835.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0747\/5665\/3309\/files\/65537f7db5a147feb686fa4cae4316a9_tplv-5jbd59dj06-image_85553b71-022a-483d-b45a-d460ef470363.png?v=1789056895","url":"https:\/\/shly-plc.com\/products\/honeywell-900c51-0021-programmable-logic-controller","provider":"SHLY-PLC","version":"1.0","type":"link"}