{"product_id":"tp-link-ism321","title":"TP-Link ISM321 Industrial Bi-Directional Gigabit SFP Module","description":"\u003cdiv id=\"ace-tp-link-ism321-copy\"\u003e \u003cstyle\u003e\n#ace-tp-link-ism321-copy { font-family: Inter, Arial, sans-serif; color: inherit; }\n\/* Reuses the current ACE calculator FAQ disclosure treatment. Scope: this product FAQ only. *\/\n#ace-tp-link-ism321-copy .ace-article-faq { --ace-family-ink: #21352b; --ace-family-muted: #5b6961; --ace-family-line: #d3d9d5; --ace-family-soft: #f4f7f4; margin: 24px 0; padding: 0; background: transparent; font-family: Inter, Arial, sans-serif; }\n#ace-tp-link-ism321-copy .ace-article-faq details.ace-form-disclosure { margin: 0 0 12px; padding: 0; border: 1px solid var(--ace-family-line); border-radius: 12px; background: #fff; overflow: visible; }\n#ace-tp-link-ism321-copy .ace-article-faq details \u003e summary { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 56px; margin: 0; padding: 16px 20px; border-radius: 12px; background: var(--ace-family-soft); color: var(--ace-family-ink); font: inherit; font-size: 16px; font-weight: 600; line-height: 1.4; list-style: none; cursor: pointer; }\n#ace-tp-link-ism321-copy .ace-article-faq summary::-webkit-details-marker { display: none; }\n#ace-tp-link-ism321-copy .ace-article-faq summary::marker { content: ''; }\n#ace-tp-link-ism321-copy .ace-article-faq summary::before, #ace-tp-link-ism321-copy .ace-article-faq summary::after { content: none; }\n#ace-tp-link-ism321-copy .ace-article-faq details[open] \u003e summary { border-radius: 12px 12px 0 0; border-bottom: 0; }\n#ace-tp-link-ism321-copy .ace-article-faq h3.ace-form-title { display: flex; align-items: center; justify-content: space-between; gap: 16px; width: 100%; min-width: 0; margin: 0 !important; padding: 0; color: var(--ace-family-ink); font-family: Inter, Arial, sans-serif; font-size: 16px; font-weight: 600; line-height: 1.35; letter-spacing: normal; text-transform: none; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-title-text { display: flex; flex: 1 1 auto; min-width: 0; margin: 0; overflow-wrap: anywhere; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-toggle { display: inline-flex; align-items: center; gap: 10px; flex: 0 0 auto; margin: 0 0 0 auto; padding: 0; color: #55605a; font-size: 12px; line-height: 1.4; font-weight: 500; white-space: nowrap; }\n#ace-tp-link-ism321-copy .ace-article-faq details \u003e summary .ace-form-collapse { display: none; }\n#ace-tp-link-ism321-copy .ace-article-faq details[open] \u003e summary .ace-form-expand { display: none; }\n#ace-tp-link-ism321-copy .ace-article-faq details[open] \u003e summary .ace-form-collapse { display: inline; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-chevron { display: inline-block; width: 8px; height: 8px; margin: 0 2px 4px; border-bottom: 2px solid currentColor; border-right: 2px solid currentColor; transform: rotate(45deg); transition: transform .15s ease; }\n#ace-tp-link-ism321-copy .ace-article-faq details[open] \u003e summary .ace-form-chevron { transform: rotate(225deg); margin-bottom: 0; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-body { margin: 0; padding: 20px; min-width: 0; color: var(--ace-family-ink); font-size: 15px; line-height: 1.65; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-body \u003e p { margin: 0; line-height: 1.65; }\n#ace-tp-link-ism321-copy .ace-article-faq summary:focus-visible { outline: 3px solid #24731a; outline-offset: 3px; }\n@media (max-width: 640px) {\n  #ace-tp-link-ism321-copy .ace-article-faq details \u003e summary { padding: 14px 16px; gap: 12px; }\n  #ace-tp-link-ism321-copy .ace-article-faq h3.ace-form-title { gap: 12px; }\n  #ace-tp-link-ism321-copy .ace-article-faq .ace-form-body { padding: 16px; }\n  #ace-tp-link-ism321-copy .ace-article-faq .ace-form-toggle { font-size: 11px; gap: 8px; }\n}\n@media (prefers-reduced-motion: reduce) { #ace-tp-link-ism321-copy .ace-article-faq .ace-form-chevron { transition: none; } }\n\n\n#ace-tp-link-ism321-copy .ace-article-faq { width:100%; max-width:100%; box-sizing:border-box; }\n#ace-tp-link-ism321-copy .ace-article-faq .ace-form-body { border:0; box-shadow:none; }\n\n#ace-tp-link-ism321-copy .ace-article-faq {width:100%;max-width:none;box-sizing:border-box;}\n\u003c\/style\u003e\n\u003ch2\u003eA Gigabit Link over One Fibre Strand\u003c\/h2\u003e\n\u003cp\u003eThe TP-Link ISM321A-20 and ISM321B-20 are complementary industrial SFP modules for a single-mode fibre link. Bidirectional WDM carries transmit and receive traffic over one strand, with the two endpoints using opposite wavelengths. Select the required endpoint under Module: each option is one transceiver, not a pair. Used together in compatible hosts, the modules support Gigabit Ethernet links up to the manufacturer’s 20KM maximum and an industrial operating range of −40°C to 85°C.\u003c\/p\u003e\n\u003ch2\u003eHighlights\u003c\/h2\u003e\n\u003ch3\u003eSingle-Strand Fibre\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1000BASE-BX bidirectional WDM over 9\/125µm single-mode fibre.\u003c\/li\u003e\n\u003cli\u003eSimplex LC\/UPC optical connector.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eChoose the Correct Endpoint\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eISM321A-20 transmits at 1550nm and receives at 1310nm.\u003c\/li\u003e\n\u003cli\u003eISM321B-20 transmits at 1310nm and receives at 1550nm.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eIndustrial Operation\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e−40°C to 85°C operating range.\u003c\/li\u003e\n\u003cli\u003eDigital Diagnostic Monitoring and hot-pluggable SFP design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003ch3\u003eUse the Available Fibre Efficiently\u003c\/h3\u003e\n\u003cp\u003eWDM carries the two directions of a Gigabit connection over one single-mode strand. This can be useful where spare fibre pairs are limited. It still needs a correctly specified optical path, suitable connectors and a supporting host at each end. The manufacturer’s maximum reach is 20KM, subject to the complete link conditions.\u003c\/p\u003e\n\u003ch3\u003ePair A with B\u003c\/h3\u003e\n\u003cp\u003eAn ISM321A-20 must connect to an ISM321B-20 for the documented link. Their transmit and receive wavelengths are complementary. Two A modules or two B modules are not a matching pair. Keeping the endpoint names visible makes it easier to order a replacement for one side without accidentally changing the remote side.\u003c\/p\u003e\n\u003ch3\u003eMatch the Module to the Host\u003c\/h3\u003e\n\u003cp\u003eThe manufacturer guide lists TP-Link switches with Gigabit SFP slots and MC220L or MC420L media converters. Confirm the exact device revision, supported module and operating mode. The 1.25Gbps published optical line rate corresponds to Gigabit Ethernet; this is not a 10GbE module.\u003c\/p\u003e\n\u003ch3\u003eMaintain a Clear Optical Installation\u003c\/h3\u003e\n\u003cp\u003eThe module supports Digital Diagnostic Monitoring through a supporting host and can be hot-plugged using the manufacturer’s handling procedure. Keep optical connectors clean, protect unused ports and respect bend limits. Its industrial temperature rating applies to the module, while the host and surrounding equipment retain their own limits.\u003c\/p\u003e\n\u003ch2\u003eSummary\u003c\/h2\u003e\n\u003cp\u003eChoose ISM321A-20 and ISM321B-20 when a compatible Gigabit network needs a complementary WDM link over one single-mode fibre strand. Check the existing remote endpoint before selecting an individual replacement.\u003c\/p\u003e\n\u003csection class=\"ace-article-faq\" aria-label=\"Frequently asked questions\"\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdetails class=\"ace-form-disclosure\"\u003e\u003csummary\u003e\u003ch3 class=\"ace-form-title\"\u003e\n\u003cspan class=\"ace-form-title-text\"\u003eDo I receive both A and B modules?\u003c\/span\u003e\u003cspan class=\"ace-form-toggle\" aria-hidden=\"true\"\u003e\u003cspan class=\"ace-form-expand\"\u003eExpand\u003c\/span\u003e\u003cspan class=\"ace-form-collapse\"\u003eCollapse\u003c\/span\u003e\u003cspan class=\"ace-form-chevron\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/h3\u003e\u003c\/summary\u003e\u003cdiv class=\"ace-form-body\"\u003e\u003cp\u003eNo. Each Module option is one transceiver. A complete documented link requires an ISM321A-20 at one end and an ISM321B-20 at the other.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails class=\"ace-form-disclosure\"\u003e\u003csummary\u003e\u003ch3 class=\"ace-form-title\"\u003e\n\u003cspan class=\"ace-form-title-text\"\u003eCan I connect two A modules or two B modules?\u003c\/span\u003e\u003cspan class=\"ace-form-toggle\" aria-hidden=\"true\"\u003e\u003cspan class=\"ace-form-expand\"\u003eExpand\u003c\/span\u003e\u003cspan class=\"ace-form-collapse\"\u003eCollapse\u003c\/span\u003e\u003cspan class=\"ace-form-chevron\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/h3\u003e\u003c\/summary\u003e\u003cdiv class=\"ace-form-body\"\u003e\u003cp\u003eNo. The documented pair uses opposite transmit and receive wavelengths: A connects to B.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails class=\"ace-form-disclosure\"\u003e\u003csummary\u003e\u003ch3 class=\"ace-form-title\"\u003e\n\u003cspan class=\"ace-form-title-text\"\u003eWhat fibre connection is required?\u003c\/span\u003e\u003cspan class=\"ace-form-toggle\" aria-hidden=\"true\"\u003e\u003cspan class=\"ace-form-expand\"\u003eExpand\u003c\/span\u003e\u003cspan class=\"ace-form-collapse\"\u003eCollapse\u003c\/span\u003e\u003cspan class=\"ace-form-chevron\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/h3\u003e\u003c\/summary\u003e\u003cdiv class=\"ace-form-body\"\u003e\u003cp\u003eA single strand of 9\/125µm single-mode fibre with the correct simplex LC\/UPC connection and a suitable end-to-end optical path.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails class=\"ace-form-disclosure\"\u003e\u003csummary\u003e\u003ch3 class=\"ace-form-title\"\u003e\n\u003cspan class=\"ace-form-title-text\"\u003eIs this a 10GbE module?\u003c\/span\u003e\u003cspan class=\"ace-form-toggle\" aria-hidden=\"true\"\u003e\u003cspan class=\"ace-form-expand\"\u003eExpand\u003c\/span\u003e\u003cspan class=\"ace-form-collapse\"\u003eCollapse\u003c\/span\u003e\u003cspan class=\"ace-form-chevron\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/h3\u003e\u003c\/summary\u003e\u003cdiv class=\"ace-form-body\"\u003e\u003cp\u003eNo. It is a Gigabit Ethernet SFP module. Its published 1.25Gbps optical line rate includes encoding overhead.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails class=\"ace-form-disclosure\"\u003e\u003csummary\u003e\u003ch3 class=\"ace-form-title\"\u003e\n\u003cspan class=\"ace-form-title-text\"\u003eWhich hosts are supported?\u003c\/span\u003e\u003cspan class=\"ace-form-toggle\" aria-hidden=\"true\"\u003e\u003cspan class=\"ace-form-expand\"\u003eExpand\u003c\/span\u003e\u003cspan class=\"ace-form-collapse\"\u003eCollapse\u003c\/span\u003e\u003cspan class=\"ace-form-chevron\"\u003e\u003c\/span\u003e\u003c\/span\u003e\n\u003c\/h3\u003e\u003c\/summary\u003e\u003cdiv class=\"ace-form-body\"\u003e\u003cp\u003eThe manufacturer guide lists TP-Link switches with Gigabit SFP slots and MC220L or MC420L media converters. Check the exact hardware revision and module support before installation.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003c\/section\u003e\n\u003c\/div\u003e","brand":"TP-Link","offers":[{"title":"ISM321A-20","offer_id":44934593609787,"sku":"ISM321A-20","price":69.58,"currency_code":"SGD","in_stock":true},{"title":"ISM321B-20","offer_id":44934593642555,"sku":"ISM321B-20","price":69.58,"currency_code":"SGD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0557\/4541\/3179\/files\/tp-link-ism321-industrial-bi-directional-gigabit-sfp-module-3786519.jpg?v=1794474135","url":"https:\/\/aceperipherals.com\/ja\/products\/tp-link-ism321","provider":"ACE Peripherals","version":"1.0","type":"link"}