Valmet EDS‑518A‑MM‑SC Ethernet Gateway – Fiber Optic Network Bridge

The Valmet EDS‑518A‑MM‑SC is an industrial Ethernet media converter that bridges 10/100Base‑TX copper networks with 100Base‑FX multi‑mode fiber optic links using SC connectors. This gateway extends network distances up to 2 kilometers, making it ideal for connecting remote I/O racks, drives, and operator stations in large industrial plants. It is designed for rugged use in control cabinets and offers transparent forwarding of all Ethernet‑based protocols, including PROFINET, EtherNet/IP, Modbus TCP, and Valmet's proprietary communication.

Fiber Optic Interface and Specifications

The fiber port operates at 1300 nm wavelength (multi‑mode) with a typical optical output power of ‑15 dBm and receiver sensitivity of ‑30 dBm. The SC connector ensures a secure, low‑loss connection. The link supports full‑duplex mode and auto‑negotiation of speed and duplex settings on the copper side. The maximum cable length is 2 km (62.5/125 µm fiber) or 1 km (50/125 µm fiber). The device includes a link loss budget of 11 dB, accommodating connector and splice losses.

Copper Ethernet Port and Data Forwarding

The copper port is an RJ45 connector with auto‑MDI/MDI‑X, supporting 10/100 Mbps and full/half‑duplex. The gateway functions as a Layer 2 bridge, forwarding frames based on MAC addresses with a store‑and‑forward mechanism. It supports up to 1024 MAC addresses in its forwarding table and has a packet buffer of 128 KB. The device also features flow control (IEEE 802.3x) and broadcast storm protection.

Power Supply and Electrical Protection

The unit is powered by a 24 V DC supply (18‑32 V) with a typical current consumption of 200 mA. It includes reverse‑polarity protection, overvoltage clamping, and a replaceable fuse. A green LED indicates power‑on, and an alarm relay provides a dry contact for reporting power loss or link failure. The terminal block accepts wires up to 2.5 mm².

Mechanical Construction and Mounting

The device is housed in a compact metal enclosure (120 mm x 70 mm x 30 mm) with an IP30 rating. It is designed for DIN rail (TS35) mounting. The front panel features diagnostic LEDs for power, link/activity on both ports, and fault status. The unit weighs approximately 0.4 kg and has a wide operating temperature range of ‑10 °C to +60 °C, suitable for industrial locations without air conditioning.

Environmental and Compliance

Humidity tolerance is 10‑95 % non‑condensing. The gateway complies with EN 61000‑6‑2 (immunity) and EN 61000‑6‑4 (emission) for industrial environments, as well as FCC Part 15 Class A. It carries CE and UL certifications. Vibration resistance is 5 g (10‑500 Hz) and shock 30 g.

Installation and Commissioning

Mount the gateway on the DIN rail and connect the power supply. Plug the copper Ethernet cable into the RJ45 port and the fiber patch cable into the SC connector. The device is self‑configuring; no software setup is required. Check the LEDs to confirm link status. If the fiber link does not come up, swap the transmit and receive fibers (TX/RX). Use a fiber power meter to verify optical levels.

Applications

This gateway is used to connect distributed control equipment over long distances, such as remote I/O cabinets in a paper mill, drive control panels in a steel plant, or outdoor analyzer shelters. It eliminates the need for copper repeaters and provides electrical isolation, improving system reliability.

Maintenance and Diagnostics

Periodically clean the fiber connectors using a proper cleaning kit. Inspect the power LED and link LEDs; a blinking link LED indicates activity. If the device fails to forward traffic, check the network settings and fiber continuity. The unit has no user‑serviceable parts; if defective, replace the entire gateway.

Spare Parts and Ordering

The EDS‑518A‑MM‑SC is a standard Valmet catalog item. A companion single‑mode version (SM‑SC) is also available for longer distances. Ensure the correct fiber type is used to avoid attenuation issues.

Conclusion

The Valmet EDS‑518A‑MM‑SC Ethernet gateway provides a reliable, cost‑effective solution for extending industrial Ethernet networks over optical fiber, ensuring robust communication in demanding environments.