{"product_id":"1756-en4tr","title":"1756-EN4TR","description":"\u003cstyle\u003e\n.flexa-desc { font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif; color:#1f2937; line-height:1.7; }\n.flexa-desc .desc-intro { font-size:15px; color:#374151; margin-bottom:0; }\n.flexa-desc .desc-section { margin-top:28px; }\n.flexa-desc .desc-section-title { font-size:15px; font-weight:700; color:#111827; text-transform:uppercase; letter-spacing:.05em; padding-bottom:10px; border-bottom:2px solid #e5e7eb; margin-bottom:16px; }\n.flexa-desc .desc-service-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:12px; }\n.flexa-desc .desc-service-card { border-radius:10px; padding:16px; border:1px solid #e5e7eb; }\n.flexa-desc .desc-service-repair { background:#fff7ed; border-color:#fed7aa; }\n.flexa-desc .desc-service-ref { background:#f0fdf4; border-color:#bbf7d0; }\n.flexa-desc .desc-service-new { background:#eff6ff; border-color:#bfdbfe; }\n.flexa-desc .desc-service-label { font-weight:700; font-size:13px; text-transform:uppercase; letter-spacing:.04em; margin-bottom:8px; }\n.flexa-desc .desc-service-repair .desc-service-label { color:#c2410c; }\n.flexa-desc .desc-service-ref .desc-service-label { color:#15803d; }\n.flexa-desc .desc-service-new .desc-service-label { color:#1d4ed8; }\n.flexa-desc .desc-service-body { font-size:13px; color:#4b5563; line-height:1.6; }\n.flexa-desc .desc-faq-item { margin-bottom:16px; padding:14px 16px; background:#f9fafb; border-radius:8px; border-left:3px solid #e5e7eb; }\n.flexa-desc .desc-faq-item:last-child { margin-bottom:0; }\n.flexa-desc .desc-faq-q { font-weight:700; font-size:14px; color:#111827; margin-bottom:6px; }\n.flexa-desc .desc-faq-a { font-size:13px; color:#4b5563; line-height:1.6; }\n.flexa-desc .desc-seo { margin-top:24px; padding:14px 16px; background:#f3f4f6; border-radius:8px; font-size:13px; color:#6b7280; line-height:1.6; }\n@media(max-width:640px){ .flexa-desc .desc-service-grid { grid-template-columns:1fr; } }\n\u003c\/style\u003e\n\u003cdiv class=\"flexa-desc\"\u003e\n  \u003cp class=\"desc-intro\"\u003e1756-EN4TR repair service is in high demand across process industries where ControlLogix platforms form the backbone of critical automation infrastructure — and Flexa Systems handles ALLEN BRADLEY 1756-EN4TR repair with the technical depth this module requires, including 1756-EN4TR refurbished units available for immediate exchange. The 1756-EN4TR is a quad-port EtherNet\/IP communication module designed for the ControlLogix 1756 chassis, supporting dual-media redundancy across two independent EtherNet\/IP networks with Device Level Ring (DLR) topology capability. Engineers searching for 1756-EN4TR troubleshooting support will find that this module operates at 100 Mbps full-duplex and manages both I\/O connections and produced\/consumed tag traffic simultaneously, making failures particularly disruptive to plant operations. The module supports up to 256 CIP connections per port and is commonly deployed in oil and gas, automotive assembly, water treatment, and food and beverage facilities where network redundancy is non-negotiable. Those researching 1756-EN4TR fault codes will note that the module's onboard diagnostics surface link-loss events, CIP connection overruns, and IGMP filtering failures through the controller's diagnostic buffer, which are critical indicators for our repair evaluation process. Industrial VFD repair and communication module repair require similar discipline — component-level analysis, firmware validation, and full functional burn-in testing before any unit leaves our bench. If you've been searching for 1756-EN4TR repair near me, Flexa Systems operates out of Lewisville TX and ships repaired and tested units nationwide with a 2-year warranty and free diagnostics on every evaluation.\u003c\/p\u003e\n\u003cdiv class=\"desc-section\"\u003e\n  \u003cdiv class=\"desc-section-title\"\u003eTechnical Specifications\u003c\/div\u003e\n  \u003ctable style=\"width:100%;border-collapse:collapse;border-radius:8px;overflow:hidden;border:1px solid #e5e7eb;\"\u003e\n\u003ctr style=\"background:#f8f9fa;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;color:#374151;width:38%;font-size:13px;\"\u003ePart Number\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;color:#1f2937;font-size:13px;\"\u003e1756-EN4TR\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;color:#374151;width:38%;font-size:13px;\"\u003eManufacturer\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;color:#1f2937;font-size:13px;\"\u003eALLEN BRADLEY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f8f9fa;\"\u003e\n\u003ctd style=\"padding:9px 14px;font-weight:600;color:#374151;width:38%;font-size:13px;\"\u003ePackage \/ Type\u003c\/td\u003e\n\u003ctd style=\"padding:9px 14px;color:#1f2937;font-size:13px;\"\u003eControlLogix EtherNet\/IP Module with CIP security\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-section\"\u003e\n  \u003cdiv class=\"desc-section-title\"\u003eCompatibility\u003c\/div\u003e\n  \u003cp style=\"font-size:14px;color:#374151;margin:0;line-height:1.7;\"\u003eThe 1756-EN4TR is compatible with all 1756 ControlLogix chassis generations, including the 1756-A4, 1756-A7, 1756-A10, and 1756-A17 backplanes, and integrates directly with ControlLogix 5580 and 5570 controllers programmed in Studio 5000 Logix Designer. ALLEN BRADLEY 1756-EN4TR integration extends to EtherNet\/IP I\/O adapters such as the 1734-AENT (POINT I\/O), 1769-L36ERM CompactLogix controllers, and Kinetix 5700 servo drives operating over CIP Motion networks. The 1756-EN4TR is a recognized 1756-EN4TR replacement for the earlier 1756-EN2TR dual-port module in applications requiring expanded port density or enhanced DLR network segmentation without chassis changes. It also interoperates with third-party EtherNet\/IP devices conforming to ODVA standards, including Cognex vision systems, Endress+Hauser instrumentation, and SMC pneumatic valve manifolds operating on the same managed switch infrastructure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-section\"\u003e\n  \u003cdiv class=\"desc-section-title\"\u003eService Options\u003c\/div\u003e\n  \u003cdiv class=\"desc-service-grid\"\u003e\n    \u003cdiv class=\"desc-service-card desc-service-repair\"\u003e\n      \u003cdiv class=\"desc-service-label\"\u003eRepair Service\u003c\/div\u003e\n      \u003cdiv class=\"desc-service-body\"\u003eShip your faulty 1756-EN4TR to our facility. Our certified technicians perform IGBT testing, capacitor inspection, gate driver diagnostics, and full load testing. Typical turnaround: 5–7 business days. 2-year warranty included.\u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"desc-service-card desc-service-ref\"\u003e\n      \u003cdiv class=\"desc-service-label\"\u003eRefurbished\u003c\/div\u003e\n      \u003cdiv class=\"desc-service-body\"\u003eIn-stock ALLEN BRADLEY 1756-EN4TR variable frequency drive, reconditioned to OEM specifications and verified under load. Ships immediately. 2-year warranty included.\u003c\/div\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"desc-service-card desc-service-new\"\u003e\n      \u003cdiv class=\"desc-service-label\"\u003eBrand New\u003c\/div\u003e\n      \u003cdiv class=\"desc-service-body\"\u003eNew 1756-EN4TR in original ALLEN BRADLEY packaging. Full manufacturer warranty applies. Contact us to confirm availability and lead time.\u003c\/div\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-section\"\u003e\n  \u003cdiv class=\"desc-section-title\"\u003eCommon Failure Modes\u003c\/div\u003e\n  \u003cul style=\"margin:0;padding-left:20px;line-height:1.7;\"\u003e\n\u003cli style=\"padding:5px 0;color:#374151;font-size:14px;\"\u003eLoss of all four EtherNet\/IP port link lights simultaneously following a facility power disturbance — 1756-EN4TR troubleshooting typically traces this to failed onboard DC-DC converter stages supplying the PHY transceivers, a documented failure pattern in units exposed to unfiltered 24VDC backplane power.\u003c\/li\u003e\n\u003cli style=\"padding:5px 0;color:#374151;font-size:14px;\"\u003eCIP connection count drops to zero and the module logs a 'Port Initialization Failure' diagnostic event in the controller's Major Fault log — a 1756-EN4TR fault condition caused by corruption of the module's non-volatile configuration EEPROM, often triggered by a hard power cycle during a firmware update.\u003c\/li\u003e\n\u003cli style=\"padding:5px 0;color:#374151;font-size:14px;\"\u003eIntermittent dropped connections on Ports 3 and 4 only, with Ports 1 and 2 maintaining stability — this asymmetric failure points to degraded magnetics (isolation transformers) on the secondary port pair, a hardware-level defect not resolvable through firmware or configuration changes.\u003c\/li\u003e\n\u003cli style=\"padding:5px 0;color:#374151;font-size:14px;\"\u003eThe module enters a steady red MODULE fault state and RSLinx Classic reports 'Identity Object Request Timeout' — this condition reflects internal processor lockup caused by electrolytic capacitor failure on the main logic board, common in units with more than seven years of continuous 24\/7 operation in high-ambient-temperature enclosures.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-section\"\u003e\n  \u003cdiv class=\"desc-section-title\"\u003eFrequently Asked Questions\u003c\/div\u003e\n  \u003cdiv class=\"desc-faq-item\"\u003e\n\u003cdiv class=\"desc-faq-q\"\u003eIs the 1756-EN4TR compatible with or a drop-in replacement for other ControlLogix Ethernet modules?\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-a\"\u003eThe 1756-EN4TR compatible with the same 1756 backplane slot footprint as the 1756-EN2TR and 1756-ENBT, making it a direct 1756-EN4TR replacement for those earlier modules in most applications without requiring ladder logic or I\/O tree modifications in Studio 5000. The primary consideration when substituting for a 1756-EN2TR is that the EN4TR presents four ports rather than two, so network topology documentation must be updated to reflect the additional DLR ring ports. For cross-brand context, the 1756-EN4TR interchangeable function covers EtherNet\/IP gateway roles previously handled by Moxa MGate units or Hilscher NT 100 gateways in hybrid networks, though native Rockwell hardware always provides tighter integration with the Logix diagnostics stack. Always confirm firmware revision compatibility with your controller's AOP (Add-On Profile) version in Studio 5000 before swapping modules in a live system.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-item\"\u003e\n\u003cdiv class=\"desc-faq-q\"\u003eHow do I know whether my 1756-EN4TR is worth repairing or should be replaced outright?\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-a\"\u003eA 1756-EN4TR repair is viable in the majority of field failures — PHY transceiver faults, EEPROM corruption, failed bulk capacitors, and damaged RJ45 port hardware are all component-level repairs that restore full functionality at a fraction of new unit cost. ALLEN BRADLEY 1756-EN4TR units showing physical damage to the backplane connector, cracked PCB substrate, or burn marks around the DC input filtering section may fall outside economical repair territory, and our technicians will flag this during free diagnostics rather than proceeding with billable labor. Units presenting only logic-level faults — steady red MODULE LED, identity object timeouts, or port initialization failures — almost always respond well to board-level repair because the communication ASICs themselves are rarely the failed component. If the module powers up and the backplane communication LED shows any activity, the probability of a successful repair is high.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-item\"\u003e\n\u003cdiv class=\"desc-faq-q\"\u003eWhere can I get 1756-EN4TR repair service with a warranty?\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-a\"\u003eFlexa Systems provides 1756-EN4TR repair service from our facility in Lewisville TX, with standard turnaround of 5-7 business days and nationwide return shipping included in the service quote. Every repaired unit carries a 2-year warranty covering both parts and labor, and we offer free diagnostics so you know the failure root cause and repair scope before committing to any cost. For operations that cannot tolerate downtime, we maintain a stock of 1756-EN4TR refurbished exchange units — if you need to buy 1756-EN4TR USA stock quickly, our inventory team can confirm availability and ship same-day on qualifying orders. Contact Flexa Systems directly to discuss ALLEN BRADLEY VFD repair, communication module repair, or advance exchange options tailored to your production schedule.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-item\"\u003e\n\u003cdiv class=\"desc-faq-q\"\u003eWhere can I get 1756-EN4TR repair service with a warranty?\u003c\/div\u003e\n\u003cdiv class=\"desc-faq-a\"\u003eFlexa Systems provides professional 1756-EN4TR repair service from our facility in Lewisville, TX, serving customers nationwide. Standard turnaround is 5–7 business days from receipt and all repaired units ship with a 2-year warranty. Rush service (2–3 business days) is also available.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c\/div\u003e\n  \u003cdiv class=\"desc-seo\"\u003eFlexa Systems specializes in ALLEN BRADLEY 1756-EN4TR variable frequency drive repair, supplying refurbished and new units backed by a 2-year warranty. All drives are load-tested before shipping. Serving industrial facilities nationwide from Lewisville, TX.\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Allen-Bradley","offers":[{"title":"Repair Service","offer_id":54608527360275,"sku":"2100000020607","price":2000.0,"currency_code":"USD","in_stock":true},{"title":"Refurbished","offer_id":54608527393043,"sku":"2100000020607","price":0.0,"currency_code":"USD","in_stock":false},{"title":"Brand New","offer_id":54608527425811,"sku":"2100000020607","price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0973\/1948\/5715\/files\/dca6a27876694c7bb3c47f64f72af9d5_default.png?v=1787645147","url":"https:\/\/flexa-systems.com\/products\/1756-en4tr","provider":"Flexa Systems","version":"1.0","type":"link"}