{"product_id":"jgd121-em11-ethercat-to-modbus-tcp-rtu-gateway-modbus-master-slave","title":"Ebyte JGD121-EM11 EtherCAT to Modbus TCP RTU Gateway Modbus Master Slave","description":"\u003cdiv class=\"ebyte-product-description\" style=\"font-family: -apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif; line-height: 1.6; color: #333333; max-width: 1000px; margin: 0 auto;\"\u003e\n\u003cp style=\"font-size: 15px; background-color: #f8f9fa; border-left: 4px solid #0066cc; padding: 12px 16px; margin-bottom: 24px;\"\u003eThe Ebyte JGD121-EM11 is an industrial EtherCAT-to-Modbus protocol conversion gateway that exchanges data between an EtherCAT fieldbus and Modbus TCP or Modbus RTU devices, supporting Modbus master, slave and transparent transfer modes over two RJ45 EtherCAT ports (IN and OUT), one dedicated Modbus TCP RJ45 port and one 3.81mm terminal RS485 interface, with a bus cycle as fast as 1~4 ms on the EtherCAT side, a 10 ms minimum cycle on Modbus TCP, 2400~6M bps on Modbus RTU, DC 8~28V supply with reverse-polarity protection and galvanic power isolation, and a 55x30x80mm housing on a standard 35mm DIN rail for -40~+85 degC industrial service.\u003c\/p\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003eKey Features \u0026amp; Advantages\u003c\/h2\u003e\n\u003cul style=\"padding-left: 20px; margin-bottom: 24px; font-size: 14px;\"\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003eThree Protocol Worlds In One Module:\u003c\/strong\u003e The gateway speaks standard EtherCAT on the fieldbus side and both Modbus TCP and standard Modbus RTU on the serial \/ Ethernet side, so an EtherCAT master such as a TwinCAT or Beckhoff PLC can read and write registers held by Modbus instruments, inverters and remote I\/O without a separate protocol computer or PC-based driver.\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003eModbus Master, Slave And Transparent Transfer:\u003c\/strong\u003e Beyond plain register mapping, the device can act as the Modbus master polling a bus of RTU slaves, as a Modbus slave exposing its EtherCAT process data, or as a transparent bridge, which is what lets the same part serve both new EtherCAT designs and brownfield retrofits where the Modbus device list is fixed and cannot be re-addressed.\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003eEtherCAT with IN and OUT Ports:\u003c\/strong\u003e Two 100M RJ45 ports give a true EtherCAT daisy chain, so the gateway sits inline at the end of a drop cable instead of consuming a dedicated master port. The ECAT indicator exposes the real EtherCAT state machine (INIT off, Pre-OP fast flash, Safe-OP slow flash, OP steady) so a commissioning engineer can read the bus state at the panel without a laptop.\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003e1~4 ms Bus Cycle Against a 10 ms Modbus Floor:\u003c\/strong\u003e The EtherCAT side runs as fast as 1~4 ms depending on master configuration and device count, while the Modbus TCP side has a 10 ms minimum cycle and Modbus RTU runs 2400~6M bps with 8 data bits, 1\/2 stop bits and None\/Odd\/Even parity. That asymmetry is the real design constraint, and it is why the mapping must be planned around a stable data snapshot rather than a per-cycle handshake.\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003eIndustrial Power Input And Protection:\u003c\/strong\u003e DC 8~28V covers the 12V, 24V and 48V control-voltage families found in cabinets, drawing 2~3W, with a red PWR indicator and documented reverse-polarity protection. The RS485 pair is brought out as A \/ B \/ G terminals plus a separate PE earth terminal, which is the correct way to bond a shielded bus without circulating ground current through the signal reference.\u003c\/li\u003e\n\u003cli style=\"margin-bottom: 8px;\"\u003e\n\u003cstrong\u003eField-Serviceable By Design:\u003c\/strong\u003e The Reload button performs three documented actions - a short press under 2 seconds reboots, a 5~10 second hold restores factory settings, and holding while powering up enters firmware upgrade mode - and the SYS and ERR lamps signal upgrade progress. Ebyte also publishes a parameter configuration tool and the ESI file so the device can be imported directly into an EtherCAT master configuration.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003eCore Specifications\u003c\/h2\u003e\n\u003cp style=\"font-size: 13px; color: #57606a; margin-bottom: 10px;\"\u003eCompiled from the JGD121-EM11 official performance parameter, indicator lamp and interface definition tables. Cells marked \u003cem\u003e[to be confirmed]\u003c\/em\u003e are not published on the product page and must be taken from the JGD121-EM11 user manual before design freeze.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 24px;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 13px; text-align: left; border: 1px solid #e0e0e0;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f3f4f6;\"\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eCategory\u003c\/th\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eItem\u003c\/th\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eProduct\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eType \/ role\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT gateway - EtherCAT to Modbus conversion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eProtocols\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eSupported\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT, Modbus TCP, Modbus RTU\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eProtocols\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus roles\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus master, Modbus slave and transparent transfer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eWorking voltage\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eDC 8~28V (V+ \/ V- on 3.81mm terminals)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePower consumption\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e2~3W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eProtection\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePower isolation with reverse-polarity protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT port\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eInterface\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRJ45 x 2 - EtherCAT IN and EtherCAT OUT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT port\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eBus cycle \/ bandwidth\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eFastest 1~4 ms (depends on master config and device count); 100M\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus TCP\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eInterface \/ cycle \/ bandwidth\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRJ45 dedicated port; minimum cycle 10 ms; 10\/100Mbps auto-sensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus RTU\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eInterface \/ baud rate\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRS485 on 3.81mm terminal (A \/ B \/ G); 2400~6M bps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus RTU\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eFrame format\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eData bits 8; stop bits 1\/2 (default 1); parity None\/Odd\/Even (default None)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eIndicators\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eLamps provided\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePWR (red), SYS (blue), ERR (red), ECAT (blue), TCP (green), RTU (green)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eControls\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eReload button\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eFactory reset: hold 5~10 s powered on. Reboot: press under 2 s. Firmware upgrade: hold while powering up\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEnvironment\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eOperating \/ storage\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e-40~+85 degC, 5%~95%RH non-condensing \/ -40~+105 degC, 5%~95%RH non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMechanical\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eDimensions \/ weight\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e55 x 30 x 80 mm (L x W x H, excluding terminals); 140 ± 5 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMechanical\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMounting\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eStandard industrial 35mm DIN rail\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eSoftware\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003ePublished resources\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eUser manual, parameter configuration tool, ESI file for master import\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMapping\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRegister map size \/ object dictionary\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e[to be confirmed - see user manual]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMapping\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eMax Modbus RTU slaves polled\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e[to be confirmed - see user manual]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eIsolation\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRated isolation voltage\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e[to be confirmed - isolation is stated, the rated voltage is not]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eCertification\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEMC \/ safety certificates\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e[to be confirmed - not stated on the product page]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eJitter \/ distributed clocks\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003e[to be confirmed - see user manual]\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003eProduct Selection Guide\u003c\/h2\u003e\n\u003cp style=\"font-size: 14px; font-weight: 600; color: #cf222e; margin-bottom: 12px;\"\u003eNotice for Selection: The JGD121-EM11 is a wired industrial Ethernet gateway - it contains no radio, so no ISM band, antenna or RF certification question applies to this model; the checks that matter are protocol-side. First confirm your EtherCAT master can import the published ESI file and that a 1~4 ms bus cycle suits your motion or I\/O scan requirements. Second confirm which Modbus role your site needs: this is a single-order-point product (one EtherCAT-to-Modbus gateway, no variants), so if your application requires a different protocol pair (for example PROFINET or a remote I\/O node rather than a protocol gateway) it belongs to a different Ebyte product family and should be confirmed before ordering. Third, verify the register mapping and slave count your project needs against the JGD121-EM11 user manual, since the map size is not published on the product page.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 32px;\"\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 13px; text-align: center; border: 1px solid #e0e0e0;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #0066cc; color: #ffffff;\"\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #0055aa;\"\u003eWiring \/ integration decision\u003c\/th\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #0055aa;\"\u003eHow the JGD121-EM11 handles it\u003c\/th\u003e\n\u003cth style=\"padding: 9px 10px; border: 1px solid #0055aa;\"\u003eWhat you must confirm\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eEtherCAT daisy chain, gateway inline at the end of the drop\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eEtherCAT IN from the upstream device, EtherCAT OUT to the next node or terminated\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eMaster cycle time and device count, since 1~4 ms depends on both\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eExisting Modbus TCP instrument or HMI on the plant LAN\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eDedicated Modbus TCP RJ45 port, 10\/100Mbps, 10 ms minimum cycle\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eWhether the gateway or the peer is the Modbus TCP client in your scheme\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eLegacy RS485 sensor or meter bus\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eRS485 A \/ B \/ G on 3.81mm terminals, 2400~6M bps, Modbus RTU\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eSlave addresses, parity and stop-bit settings, and the maximum slave count in the manual\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9fafb;\"\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eCabinet with 12V, 24V or 48V control voltage\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eDC 8~28V input, 2~3W, reverse-polarity protected, isolated supply\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003e48V nominal systems exceed 28V and are outside the stated range\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eNeed to expose EtherCAT data to an unrelated Modbus TCP SCADA\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0;\"\u003eModbus slave mode publishes the process data as holding registers\u003c\/td\u003e\n\u003ctd style=\"padding: 9px 10px; border: 1px solid #e0e0e0; text-align: left;\"\u003eRegister map layout from the manual, and scan rate versus the 10 ms floor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"ebyte-detail-images\" style=\"margin-bottom: 30px;\"\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/1_521211c5-ceb3-47d3-a00a-f6fdba1c616c.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 1\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/2_93631011-39eb-4e75-accc-6ecb17924843.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 2\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/3_26fb49b4-e5d2-48f2-a650-b57404a89a0f.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 3\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/4_24cb876e-2819-4834-9dd7-f85c3848c4be.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 4\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/5_a3361a31-346e-4879-8524-ec01e3eb6797.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 5\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/6_eb108117-c826-4d76-8491-0fff88731413.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 6\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/7_e4debcde-331d-4dfb-9616-e0532fc4c119.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 7\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/8_ca687d8c-a9af-4410-976d-749d31b9a570.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 8\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/9_0c64be6c-0cda-4996-8448-364eeff2eaae.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 9\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/10_d25c6924-d6e8-4d13-9fba-b0a56e74bce7.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 10\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/11_43f76368-6784-4180-8533-283bc173b789.jpg?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 11\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/12_baac45bd-51fa-411b-8aef-b88c602edfa5.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 12\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/13_f5c60482-616b-466b-948b-03b306384999.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 13\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/14_0e50e084-68c5-4b99-a7dc-47f93dccbdf5.png?v=1794449152\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 14\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/15_a625b4cc-14aa-45b8-b039-9f2b0cd88450.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 15\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/16_549b13e2-37e0-43cc-a810-12763310dd1c.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 16\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/17_f6aebdba-d9fe-48b2-be44-c0c3b52e5d9b.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 17\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/18_00441cef-f927-4051-80e9-67b5d50376fd.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 18\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003cp style=\"margin: 0; padding: 0; line-height: 0; text-align: center;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/19_b44a72ed-2075-466f-b5d6-93f73e9dac86.png?v=1794449151\" alt=\"Ebyte JGD121-EM11 EtherCAT Modbus Gateway Detail 19\" style=\"width: 100%; max-width: 100%; display: block; margin: 0 auto;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003eIndustrial Installation \u0026amp; Wiring\u003c\/h2\u003e\n\u003cdiv style=\"font-size: 14px; margin-bottom: 24px;\"\u003e\n\u003cp\u003e\u003cstrong\u003e1. Mechanical:\u003c\/strong\u003e Clip the 55x30x80mm housing onto a standard 35mm DIN rail. The quoted dimensions exclude the terminals, so allow the terminal depth plus cable bend radius at the front, and keep neighbouring devices clear of the RS485 and power terminal block so a screwdriver can reach it during commissioning.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Power:\u003c\/strong\u003e Feed DC 8~28V to the V+ and V- 3.81mm terminals. The supply is isolated and reverse-polarity protected, but it is still correct practice to fuse the branch and to keep the 2~3W load on a rail shared with relays or contactors away from the noisy coil side. The red PWR lamp confirms the internal rail is up.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. RS485 bus:\u003c\/strong\u003e Connect A to A, B to B and G to the common reference of the trunk, and bond the cable screen at one end to the PE terminal. Run the bus as a single daisy chain rather than star or tapped branches, set 8 data bits with the stop bits and parity the slaves expect (default 1 stop, No parity), and start at a conservative baud rate before raising toward the 2400~6M bps ceiling, because long or poorly terminated RS485 runs fail at high baud long before the transistors reach their limit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e4. Ethernet:\u003c\/strong\u003e EtherCAT IN receives the drop cable from the master or the previous node, EtherCAT OUT continues the chain. The Modbus TCP port is separate and must not be bridged into the EtherCAT segment - the whole point of the third port is that the two networks stay physically isolated and only the gateway moves data between them.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e5. Read the lamps before you open a laptop:\u003c\/strong\u003e ECAT steady blue means OP, slow flash Safe-OP, fast flash Pre-OP, off INIT. SYS steady blue means the device has entered OP; a 500ms slow flash means it has not; off means an operating fault. ERR lit is an EtherCAT communication error. On TCP and RTU, a 200ms fast flash means normal traffic, a 1s slow flash means the channel is enabled but idle, and a 3s steady lamp indicates a communication error on that channel.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e6. Commissioning and firmware:\u003c\/strong\u003e Use the published parameter configuration tool to set the Modbus role, mapping and serial parameters, and import the published ESI file into the EtherCAT master so the module appears with the correct process-data description. For firmware work, hold Reload while powering up to enter upgrade mode - SYS and ERR flash together slowly in the upgrade wait state and fast at 0.5s during writing. A 5~10 second hold once running restores factory settings, so record your mapping first.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003ePractical Application Scenarios\u003c\/h2\u003e\n\u003cdiv style=\"font-size: 14px; margin-bottom: 24px;\"\u003e\n\u003ch3 style=\"font-size: 16px; color: #1f2937; margin-top: 16px; margin-bottom: 6px;\"\u003e1. Bringing Legacy Modbus Meters and Drives onto a New EtherCAT Line\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eA machine builder retrofitting an EtherCAT-based line usually keeps the installed Modbus instruments: energy meters, soft starters, VFDs and torque controllers that cannot be re-protocolled. The gateway polls those RTU slaves and republishes their values as EtherCAT process data, so the PLC program sees ordinary inputs and outputs instead of a serial driver, and the 1~4 ms bus cycle keeps the motion-side scan unaffected by the slower serial side.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 16px; color: #1f2937; margin-top: 16px; margin-bottom: 6px;\"\u003e2. Exposing an EtherCAT Cell to Modbus TCP SCADA or an HMI\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003ePlant SCADA, energy dashboards and third-party HMIs are overwhelmingly Modbus TCP. Running the gateway in Modbus slave mode turns the cell process data into holding registers on the dedicated TCP port, so the supervision system reads it without ever touching the EtherCAT network - a clean security and stability boundary as well as a protocol convenience.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 16px; color: #1f2937; margin-top: 16px; margin-bottom: 6px;\"\u003e3. Substation, Water and Environmental Telemetry Cabinets\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eUnattended cabinets aggregate RS485 flow, water-quality and weather sensors under Modbus RTU and hand the data upstream over EtherCAT to a controller or edge gateway. The -40~+85 degC rating, 5%~95%RH non-condensing tolerance, isolated DC 8~28V input and PE-bonded bus make the part usable in unheated kiosks, and the per-channel TCP and RTU lamps let a technician confirm which link died without instrumentation.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 16px; color: #1f2937; margin-top: 16px; margin-bottom: 6px;\"\u003e4. Test Rigs and Batch Equipment with Mixed Vendor Buses\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eA test bench frequently mixes a TwinCAT or Beckhoff controller with cheap Modbus power supplies, loads and environmental chambers. Transparent transfer mode passes Modbus requests across the EtherCAT side without the master having to model every register, which shortens integration on one-off equipment where the register documentation is thin and the commissioning window is short.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2 style=\"font-size: 20px; color: #111827; border-bottom: 2px solid #e5e7eb; padding-bottom: 8px; margin-top: 32px; margin-bottom: 16px;\"\u003eFAQ Section\u003c\/h2\u003e\n\u003cdiv style=\"font-size: 14px; margin-bottom: 24px;\"\u003e\n\u003ch3 style=\"font-size: 15px; color: #1f2937; margin-top: 14px; margin-bottom: 6px;\"\u003eQ1: What is the practical difference between Modbus master, slave and transparent transfer on this gateway?\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eMaster mode means the gateway itself initiates requests, so it polls your RS485 or Modbus TCP slaves on a schedule and places the answers into EtherCAT process data - use it when the other devices are dumb responders. Slave mode means the gateway exposes its own registers and something else polls it - use it for SCADA or HMI reads. Transparent transfer passes Modbus frames through without the gateway interpreting every register, which is what you want during commissioning or when the peer device has a non-standard map. Pick the mode first, because it determines how you write the PLC or SCADA side.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 15px; color: #1f2937; margin-top: 14px; margin-bottom: 6px;\"\u003eQ2: The ECAT lamp is flashing slowly - is the device faulty?\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eNo. The ECAT lamp mirrors the EtherCAT slave state machine: off is INIT, fast flash is PRE-OP, slow flash is SAFE-OP and steady is OP. A slow-flash device has been detected by the master but has not been moved to OP, which is usually a master-side condition - the XML \/ ESI description does not match the firmware, the expected process-data length differs, or the master has not issued the SAFE-OP to OP transition. Check the master state and the ESI file version before suspecting hardware, and cross-read SYS, which is steady blue only in OP.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 15px; color: #1f2937; margin-top: 14px; margin-bottom: 6px;\"\u003eQ3: Can I put this gateway on a 48V DC control supply?\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eNo. The stated working range is DC 8~28V, which covers 12V and 24V nominal systems with headroom and, with care, 48V logic supplies that are actually sitting near 24V - but a genuine 48V rail exceeds the specified maximum. Use a DC-DC isolating converter to feed the module 24V, or select a product rated for the 48V family. Note also that a 24V rail derived from an unregulated rectifier under charge can ride above 28V, which is the more common way this input gets over-voltaged in the field.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 15px; color: #1f2937; margin-top: 14px; margin-bottom: 6px;\"\u003eQ4: Why does my Modbus side look slower than the EtherCAT side, and does that matter?\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 12px;\"\u003eIt is expected and it is a design input, not a fault. EtherCAT is a fast, deterministic on-the-fly copy at 1~4 ms, while Modbus TCP carries a 10 ms minimum cycle here and Modbus RTU is bounded by baud rate, slave turnaround and frame length. The gateway therefore samples or refreshes Modbus data at Modbus speed and publishes it to the bus at EtherCAT speed. Size your application around that: use the EtherCAT side for values the control loop consumes, do not build a control loop that waits on a Modbus round trip inside one bus cycle, and if you need faster serial data, raise the baud rate, shorten the trunk or split the slaves across two buses.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Ebyte Official Store - IoT Module Manufacturer","offers":[{"title":"JGD121-EM11 (EtherCAT to Modbus TCP RTU Gateway, DC 8~28V, DIN Rail)","offer_id":48855582474445,"sku":"JGD121-EM11","price":76.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0615\/5911\/1885\/files\/01_695fd483-246a-4adf-9330-01ac4b1dd796.jpg?v=1794449203","url":"https:\/\/ebyteiot.com\/products\/jgd121-em11-ethercat-to-modbus-tcp-rtu-gateway-modbus-master-slave","provider":"Ebyte Official Store - IoT Module Manufacturer","version":"1.0","type":"link"}