Implement Ethernet network connections with reliable fiber-optic or shielded-twisted-pair (STP) copper cables.
Distribute IRIG-B time to SEL products and other devices, and connect GPS and radio antennas to SEL devices with an antenna connection.
SEL integrates multiple pieces of equipment and hardware (from SEL and other vendors) into a single assembly or kit, enabling one-stop shopping for parts and labor with a quick turnaround time.
SEL designs, manufactures, tests, and delivers custom protection, control, and metering panels as well as control cabinets and retrofit doors. SEL panels are supported by an unmatched warranty and extraordinary customer service. Panels, cabinets, and doors are built to match customer specifications and needs.
SEL provides reliable finished (terminated) cables, built to IPC workmanship standards in our ISO 9001 certified plants – And, they are covered by our worldwide, ten-year warranty. A variety of standard and customized twisted pair and coaxial cables and connector combinations are available from SEL.
The SEL ICON is a wide-area-networking multiplexer optimized for industrial and utility applications. ICON virtual synchronous networking (VSN) preserves the performance characteristics of time-division multiplexing (TDM) when converting to Ethernet as a transport protocol. By combining TDM and Ethernet transport options with a comprehensive range of data interfaces, the ICON makes it easy to migrate legacy network technologies to a converged IT/OT packet-based solution.
SEL sells wall-mount AC power supplies as accessories for communications and networking equipment. These AC power supplies are commercial temperature rated and appropriate for testing and office environments.
The RadioRANGER solution reduces the need to access vaults or open pad-mounted enclosures to retrieve the FCI status, decreasing fault-locating time and improving utility personnel safety.
Overhead AutoRANGER Fault Indicators are self-adjusting fault indicators for overhead lines. You can apply the SEL-AR360 on distribution systems up to 35 kV and the SEL-AR on systems up to 69 kV for permanent and momentary fault indication using bright LEDs and flash patterns.
SEL Underground AutoRANGER Fault Indicators are reliable, self-adjusting, settings-free faulted circuit indicators suitable for applications with fault current ranging from 50 A to greater than 1,200 A. They are designed for a variety of underground applications and can be paired with a range of display options.
Economical timed-reset fault indicator eliminates false reset concerns.
Select your trip value in the field. Stock one fault indicator for a variety of system conditions.
Add a six-foot or fifteen-foot EIA-232 serial port cable to a PC USB port to communicate with SEL relays and other devices with EIA-232 serial ports.
Use arc-flash detection cables with SEL-751 and SEL-751A Relays to protect people and equipment from arc-flash events.
Safely connect SEL fiber-optic transceivers, I/O modules, and Ethernet devices.
SEL provides high-quality fiber optic cable solutions in customer specified lengths. Various cables sizes, jacket types, and strand counts are available. Field termination kits are also available.
SEL provides high-quality fiber optic cable solutions in customer specified lengths. Various cables sizes, jacket types, and strand counts are available. Field termination kits are also available.
Safely connect your EIA-232 communications ports using SEL fiber-optic cable and SEL fiber-optic transceivers.
Line-powered fault indicator provides years of maintenance-free operation.
Load current-powered faulted circuit indicator (FCI) with no minimum voltage requirement provides a solution for low-voltage applications.
Install current monitoring sensors without interrupting service.
Battery-free automatic reset fault indicator provides maintenance-free fault indication.
Troubleshoot problematic sections of overhead systems.
Apply the SEL-FLT and SEL-FLR Fault and Load Transmitter and Receiver System to improve distribution system reliability metrics and customer satisfaction. The SEL-FLT Fault and Load Transmitter operates using 900 MHz wireless sensors that continuously monitor the line for faults while providing load data with 2 percent accuracy to the SEL-FLR Fault and Load Receiver, with a range of up to 10 miles. Speed up system restoration by pinpointing faults and knowing where to send repair crews. Accurate and real-time load monitoring enables improved switching decisions, since operators confidently know which viable alternate feeders are available to pick up the impacted customers.
Reliable ground fault detection for three-conductor cable applications.
Provide auxiliary dc power to your protective relays in the classroom or lab.
Economically sense voltage and eliminate the need for potential transformers or analog sensors.
Find faults faster on urban systems with the SEL-PILC Fault Indicator.
A submersible separable-core current transformer provides reliable use in subsurface vaults where flooding can occur and where it is difficult to open the primary conductor to install a solid-core-type CT.
Arms and resets from transformer secondary voltage—no minimum load current necessary.
With breakthrough time-domain technologies, the SEL-T400L Time-Domain Line Protection trips in as fast as 1 millisecond, records events with 1 MHz sampling, and locates faults accurately to the nearest tower with single- and double-ended traveling-wave fault locators.
Test traveling-wave relay performance under various conditions with the SEL-T4287 Traveling-Wave Test System. The SEL-T4287 accurately tests single- and double-ended traveling-wave fault locators and traveling-wave protection elements.
The most economical fault-indicating solution for elbow test point applications.
Automatic timed reset provides permanent and transient fault-finding capability.
This distribution automation sensor stores load data and monitors the distribution line for loss of current or fault events. Reports are transmitted to an access point on a communications network using an integrated radio.
Apply the SEL-300G Relay for comprehensive primary and backup generator protection.
Apply the SEL-311C Relay for complete protection, monitoring, and control of transmission lines.
Use the SEL-311L Relay with integral four-zone distance backup for easy-to-apply, high-speed line protection.
The SEL-321 Relay delivers outstanding EHV protection, performance, and features—at a price practical for all voltage levels and with the features you need for system integration.
Select the SEL-321-5 for 50 Hz applications requiring enhanced single-pole tripping, phase and ground distance, directional overcurrent, and negative-sequence protection.
The SEL-351 Relay has built-in Ethernet and IEEE C37.118 synchrophasors, and is ideal for directional overcurrent applications. Optional Mirrored Bits communications and power quality monitoring add flexibility to solutions. The SEL-351 is the protection standard for utility and industrial electrical systems around the world.
The SEL-351A Protection System has built-in Ethernet and IEEE C37.118 synchrophasors, and is the economical solution for overcurrent protection. Easy-to-use feeder protection and innovative features like SEL’s Best Choice Ground Directional Element logic and SELogic control equations provide superior protection on utility and industrial power systems.
The SEL-351RS Kestrel is a lightweight, advanced recloser control with integrated logic, communications, and comprehensive protection for single-phase applications. Convenient operator controls allow easy local access to metering and event data.
The SEL-351S Relay provides wide-area system stability awareness with IEEE C37.118 synchrophasors and simplifies communications with built-in Ethernet. Large, easy-to-use operator controls and optional independent SafeLock trip/close pushbuttons enhance operation and simplify panels.
Apply an SEL-352 Breaker Failure Relay per circuit breaker to detect breaker failure conditions for single-pole and three-pole tripping applications with any bus/breaker arrangement.
Protect and control any two-, three-, or four-winding power transformer with the SEL-387, which provides thermal and through-fault monitoring, and with SELogic Control Equations, can detect breaker failure.
Apply the SEL-387A to protect any two-winding power transformer and perform predictive maintenance based on accumulated through-fault duty (as compared to transformer capability as defined in ANSI Standard C57.109).
Protect power transformers with up to three windings, as well as reactors, generators, large motors, and other multi-terminal power apparatus.
Use SEL-387L Line Current Differential Relays for economical, easy-to-apply line protection.
Apply the SEL-401 for substations with IEC 61850-9-2 sampled values (SV) systems. Sample analog data, such as currents and voltages, then publish those data to a fiber-based Ethernet network for use in other IEDs such as compliant SEL-400-series relays.
With comprehensive distance and differential protection the SEL-411L allows you to stock one relay for all transmission lines. The SEL-411L is also the only relay with traveling-wave fault location which pinpoints faults to the nearest tower or span.
Protect transmission lines with high-speed distance and directional functions.
Quickly integrate bay control status and control for breakers and disconnect switches with full automation and protection in one device. With advanced synchrophasor measurement, the SEL-451 provides system stability awareness. Choose between Ethernet and serial communications ports with DNP3 and IEC 61850 Edition 2 protocols.
Provide low-impedance bus differential protection, dynamic zone configuration, circuit breaker failure protection, backup overcurrent protection, check zones and voltage inputs for increased security.
The SEL-487E provides comprehensive protection, metering, monitoring, and automation of power transformer applications with up to five 3-phase restraint current inputs, two 3-phase voltage inputs, and three independent neutral current inputs with restricted earth fault (REF) elements.
Simplify relay settings and reduce inventory with one relay for all your capacitor bank needs. The versatile SEL-487V protects and controls both grounded and ungrounded, single- and double-wye capacitor bank applications.
Simplify protection in two-high switchgear with two independent sets of protection elements in one compact relay.
Apply low-cost, compact package with essential protection and control elements for distributed generation.
The SEL-551 Overcurrent/Reclosing Relay replaces the many relays, control switches, and wiring required in traditional distribution substation protection and control panels. The relay also replaces line recloser control packages at a fraction of the cost.
The SEL-551C Overcurrent/Reclosing Relay combines overcurrent protection, built-in I/O, enhanced communications features, and multiple-shot reclosing in one compact relay. Great for industrial, commercial, and utility, primary or secondary overcurrent protection.
Apply economical differential protection for two-winding transformers or any two-terminal apparatus.
Provide single-zone high-impedance bus differential protection, backup overcurrent protection, and breaker failure protection for any number of terminals in a bus. Use the simple settings and dedicated same-ratio CTs to create a cost-effective and easily expandable bus protection solution.
Use the SEL-651R for your most demanding recloser applications. The SEL-651R is a plug-compatible replacement for most Kyle/Cooper FXA, FXB, and Form 3, 3A, 4, 4A, 4C, 5, and 6 recloser controls. Built-in harmonic metering and voltage sag, swell, and interruption reporting help improve power quality.
The SEL-651RA Recloser Control offers exceptional protection and communications capabilities for Automatic Network Reconfiguration and other distribution automation needs. These capabilities assist you in maintaining reliable service to as many customers as possible in the event of a fault.
The SEL-700G is the right solution for utility and industrial generator protection, with an autosynchronizer, flexible I/O, and advanced communications. Apply the SEL-700G for comprehensive primary and backup generator protection.
Monitor and Control Critical Substation Apparatus With One Powerful Package
The SEL-710 Motor Protection Relay dynamically calculates slip. This premiere motor protection scheme allows maximum start times. Thermal motor protection models give the SEL-710 advanced protection beyond industry standards.
The SEL-710-5 provides synchronous motor protection, starting control, broken rotor bar detection, and now arc-flash protection.
The SEL-734 Meter exceeds ANSI and IEC Class 0.2 accuracy with four-quadrant energy and demand metering. Advanced load profile trending compatible with MV-90®, DNP3, and Modbus® protocols ensures integration with practically any billing system.
The SEL-734B provides advanced monitoring and control capabilities for applications such as three-phase capacitor bank control and feeder automation.
The SEL-735 Power Quality and Revenue Meter is fully Class A-compliant to the IEC 61000-4-30 power quality standard. With reliable Class A measurement, operators can identify power system anomalies and isolate their source with confidence.
Use the SEL-749M to protect and control all types of three-phase motors, including two-speed and reduced-voltage start motors.
The SEL-751 is ideal for directional overcurrent, fault location, arc-flash detection, and high-impedance fault detection applications. Flexible I/O options, easy mounting, and fast settings make the SEL-751 the right solution for industrial and utility feeder protection.
The SEL-751A offers industrial and utility feeder protection with flexible I/O options, easy retrofit, and fast setup and configuration. The SEL-751A provides complete feeder protection with overcurrent, voltage, and frequency elements. The SEL-751A remediates arc-flash hazards with arc-flash detection.
The SEL-787 Relay is a versatile, two-winding current differential relay that protects industrial transformers. Monitor transformer health with cumulative through-fault current recording, and for the first time in the industry, automatically check and generate differential compensation settings with the Commissioning Assistant Software.
Provide complete current differential and overcurrent protection for three- and four-winding transformers. Select the SEL-787-3E or SEL-787-3S for current- and voltage-based protection on three-terminal transformers, and choose the SEL-787-4X for current differential and overcurrent-based protection on four-winding transformers.
The SEL-849 provides current, voltage, and thermal-based protection, arc-flash detection, and power metering for motor protection applications.
With an MTBF of 10x over other industrial computers and 10-year warranty, SEL computers are reliable and withstand –40°C to +75°C. Quality and service are what we have built our name on. Our computers are built to the same tough standards as our protective relays.
Replace remote terminal units and other devices with one reliable system.
Low-cost, high-speed bus protection, automated bus sectionalizing, breaker failure protection, and multiple terminal line protection. Interconnect up to 15 devices using Mirrored Bits communications.
Use the SEL-2126 Fiber-Optic Transfer Switch to maintain relay communications during bypass operations.
The Axion is a fully integrated, modular I/O and control solution suitable for many utility and industrial applications. It combines the communications, built-in security, and IEC 61131 logic engine of the SEL Real-Time Automation Controller (RTAC) product line with a durable suite of I/O modules that provide high-speed, deterministic control performance over an Ethernet network.
Compact, precision-time device for limited space and high-accuracy timing to ±100 nanoseconds.
The SEL-2407 provides time display, reliability, durability and high-accuracy timing to ± 100 nanoseconds.
The SEL-2411 offers rugged I/O for SCADA, PLC, monitoring, and control in harsh physical and electrical environments.
The SEL-2411P Pump Automation Controller is a complete preconfigured, SCADA-ready system for control and monitoring of water and wastewater pump applications.
The SEL-2414 Transformer Monitor provides an exceptional combination of monitoring, control, and communications in a compact package.
The SEL-2431 is compatible with most 32-step, single-phase voltage regulators manufactured in North America. Use various hinge and wiring kits to easily upgrade existing controls without removing the regulator from service. Quickly integrate the SEL-2431 into existing communications schemes using EIA-232, EIA-485, fiber-optic ST, or fiber-optic V-pin connectors.
The SEL-2440 DPAC is a 48-point discrete programmable automation controller that is ideal for utility and industrial applications as a rugged and reliable I/O solution at an economical price.
The SEL-2488 raises the bar for satellite-synchronized clocks by providing industry-leading accuracy, time distribution, security, and ease of use not offered in other critical infrastructure clocks.
Apply SEL-2505 Remote I/O Modules to use two optical fibers instead of 32 wires to reduce costs, improve safety, and boost reliability.
Rack-Mount Remote I/O Module with 8 digital inputs and 8 digital outputs using SEL Mirrored Bits communications.
Connect the SEL-2507 to the SEL-T400L Time-Domain Line Protection or another SEL-2507 at 115.2 kbps to provide ultra-high-speed remote I/O.
The SEL-2523 enables you to easily annunciate alarms and to use flexible communications links that eliminate duplicate I/O wiring to RTU and DCS systems, receive data for local logic operation or display, and transmit information to remote sites.
The compact, ten-window SEL-2533 with communications ports is ideal for displaying alarm conditions and notifying personnel for each individual rack, panel, generator, equipment block, power line terminal, assembly line, conveyor, or other apparatus.
SEL-2595 Teleprotection Terminal provides secure, high-speed contact transfer through communications multiplexers, using an IEEE C37.94 standard fiber-optic interface.
Measure and transmit data from up to 12 RTDs and a single contact status located in transformers, breakers, motors, generators, or other system apparatus.
Although a trip coil monitor may be a small part of a protection system, its misoperation can be a huge problem and can cost utilities time and money. The SEL-2652 brings increased reliability and versatility to trip coil monitoring, giving you peace of mind that your circuit breakers will operate when necessary.
Add the SEL-2664 Field Ground Module to the SEL-300G or SEL-700G to protect all the critical components in your generator with one comprehensive relay. Or, add the SEL-2664 to the SEL-2664S to complete ground fault protection on both the rotor and stator.
Protect high-impedance grounded generators from ground faults at standstill, during startup, and while running with the multisine frequency injection and neutral overvoltage-based protection in the SEL-2664S.
The SEL-2725 is an unmanaged five-port switch and copper-to-fiber media converter. Apply to build reliable, safe Ethernet networks in electrical substations, plants, and other mission critical sites.
The SEL-2726U Eight-Port Ethernet Switch is the dependable choice in Ethernet connectivity, whether it’s used in testing stations, laboratories, research and development, manufacturing, or other exacting work areas.
The SEL-2730M is a managed 24-port Layer 2 switch. Apply the switch to build reliable, safe Ethernet networks in electrical substations, plants, and other mission-critical sites. Connect to devices using shielded Category 5/5e/6 copper cables and single- or multimode LC fiber-optic cables.
The SEL-2730U is an unmanaged 24-port Ethernet switch, designed for the harsh environments commonly found in the energy and utility industries. The switch supports communications infrastructure built for engineering access, supervisory control and data acquisition (SCADA), and real-time data communications, while offering the same reliability found in SEL protective relays.
The SEL-2740S is designed for the harsh environments commonly found in the energy and utility sectors. The SEL-2740S is the industry’s first SDN-enabled switch. Built for the highest reliability and best performance, it revolutionizes the way networks are engineered and maintained.
The SEL-2741 enables deny-by-default SDN—ideal for Ethernet applications requiring real-time control, measurement, and data acquisition, such as IEC 61850-based communications.
Communicate 500 meters with port-powered fiber-optic transceivers / modems.
Communicate up to 500 meters with port powered fiber-optic transceivers
Communicate up to 4 kilometers with port powered fiber-optic transceivers
Communicate up to 4 kilometers with port powered fiber-optic transceivers.
Communicate 2 to 15 kilometers with port-powered fiber-optic transceivers.
Communicate up to 500 meters on multidrop and point-to-point EIA-485 networks.
Communicate up to 4 kilometers on multidrop and point-to-point EIA-485 networks
Communicate up to 23 kilometers with port-powered single-mode fiber-optic transceivers.
Communicate from 16 to 80 kilometers with port-powered single-mode fiber-optic transceivers.
Communicate from 16 to 110 kilometers with port-powered single-mode fiber-optic transceivers.
Connect EIA-232 devices to an EIA-485 network with tough, flexible SEL-2886 EIA-232 to EIA-485 Interface Converter.
Adds Ethernet connectivity to an SEL device using its EIA-232 serial port.
Convert asynchronous EIA-232 serial communications interfaces to the IEEE C37.94 optical standard.
Isolate EIA-232 and IRIG-B signal lines to reduce signal-ground current induced by adjacent high-current conductors.
Carry an SEL-2924 for an always-secure wireless EIA-232 connection.
Avoid exposing personnel to hazardous conditions by enabling them to control and monitor equipment from their trucks or other safe locations.
Instead of unplugging your modem, establish strong access controls with the SEL-3025 and use powerful AES-128/256 and SHA-1/256 to encrypt and authenticate serial links with the Secure SCADA Communications Protocol (SSCP).
The SEL-3031 combines three serial data ports in one radio, allowing up to three different connections and protocols to operate simultaneously. The radio transmits data in the license-free 900 MHz ISM band, providing an economical communications path and backup communications system.
The SEL-3060 is a multipurpose Ethernet radio for distribution automation wireless applications, including SCADA and engineering access.
The SEL-3061 Cellular Router is a secure wireless communication solution designed for critical applications. For electric utilities, the router provides connectivity to devices like recloser controls, motor-operated switches, capacitor banks, voltage regulators, substations, and much more.
Convert asynchronous EIA-232 serial communications interfaces to the IEEE C37.94 optical standard.
With an MTBF of 10x greater than other industrial computers and a 10-year warranty, SEL computers are reliable and withstand temperatures from –40°C to +75°C.
With an MTBF of 10x over other industrial computers and a 10-year warranty, SEL computers are reliable and withstand temperatures from –40°C to +75°C.
This tough computer by SEL includes different processor options, more storage options, more USB and ethernet options; and with no moving parts and using error correcting memory technologies it still achieves reliability expectations and specifications.
The SEL-3355 is a versatile computing platform, configurable as a Blueframe application platform or an industrial computer running Windows or Linux operating systems.
The SEL-3360 is a versatile computing platform, configurable as a Blueframe application platform or an industrial computer running Windows or Linux operating systems.
The SEL-3373 PDC provides phasor data concentration and local archiving for up to 40 phasor measurement units (PMUs). It is designed to operate reliably in harsh substation environments and offers several innovative features.
Combine the power of synchrophasor message processing with flexible programmable logic for wide-area protection and control applications.
The SEL-3390E4 Network Adapter is a PCIe card designed to provide network expansion capabilities for SEL's flexible, robust computer line.
The SEL-3390S8 Serial Adapter is a PCIe expansion card designed to expand the serial I/O capabilities of SEL's flexible, robust computer line.
The SEL-3400 is an inexpensive, reliable, and precise way to distribute demodulated IRIG-B time information. With twelve IRIG-B distribution ports and a bright display, the SEL-3400 is ideal for time distribution in panels.
High-visibility digital clock display synchronized by IRIG-B time signal may be connected together to make synchronized clock system.
Send delay-compensated demodulated IRIG-B up to 4 km over fiber-optic cable with SEL-3405 High-Accuracy IRIG-B Fiber-Optic Transceivers.
The SEL-3505/3505-3 RTACs are compact, lower-voltage versions of the SEL-3530 RTAC. All of the standard features of the RTAC are included in the SEL-3505/3505-3 RTACs, making them very powerful options for protocol conversion and secure communications gateways to remote intelligent electronic device (IED) installations.
The SEL-3530 RTAC is a complete automation platform designed for substation and industrial control applications. An IEC 61131 logic engine and multiple client/server protocols are standard.
The SEL-3532 is a Compact Flash image that easily transforms an SEL industrial computing platform to enable all of the standard features that are available in the SEL Real-Time Automation Controller (RTAC).
The SEL-3555 RTAC is the most powerful RTAC with unmatched performance and high speed logic capabilities for critical automation, protection, and control schemes. The integrated video port on the RTAC eliminates the need for an additional computer for viewing the HMI. The rugged and reliable design makes it ideal for operating in harsh environmental conditions.
The SEL-3573 Station PDC is a hardware-based phasor data concentrator with integrated archiving. It concentrates as many as 120 phasor measurement unit (PMU) inputs at rates as fast as 240 messages per second, exceeding the IEEE C37.118-2011 requirement of 60 messages per second. Additionally, the SEL-3573 includes a built-in archiving feature that can be used as part of a NERC PRC-002-2 disturbance recording system. Local archiving of data at each substation protects against loss of data, even in the event of a communications outage. The SEL-3573 offers archiving for both continuous and predefined trigger conditions, so it never misses capturing data necessary for post-disturbance analysis. The SEL-3573 provides the real-time performance needed for synchrophasor-based control schemes.
Economically add serial ports to communications processors or computers, and provide secure Ethernet access to serial products.
The SEL-3620 is the ideal substation access point and jump host to help satisfy NERC CIP requirements for securing the electronic security perimeter (ESP). The substation-hardened SEL-3620 secures all Ethernet and serial communications between the enterprise and remote networks, and interoperates with existing business IT and control systems using Internet Protocol Security (IPsec). The SEL-3620 manages passwords for and secures access to relays and IEDs.
The SEL-3622 hosts the same feature set as the SEL-3620 Ethernet Security Gateway in a smaller, low-power form factor and is perfect for cabinets and other low-power locations.
The SEL-RTS Relay Test System is designed for testing protective relays having low-level test capabilities. The system consists of the SEL-AMS Adaptive Multichannel Source and either the SEL-5401 or SELtest software.
The SEL-4388 gives engineers and technicians the power to accelerate commissioning and bench testing, and to improve cable identification, training, and maintenance.
The SEL-4520 provides a convenient way to test the operation of arc-flash detection relays installed in metal-clad and metal-enclosed switchgear. The SEL-4520 is used to test the SEL-751 and SEL-751A Feeder Protection Relays and other arc-flash detection relays that use light and overcurrent for sensing an arc-flash event.
Easily set and commission devices using acSELerator QuickSet SEL-5030 Software.
Architect configures and documents IEC 61850 systems that include GOOSE, Sampled Values, or Manufacturing Message Specification (MMS) for process bus and SCADA applications.
acSELerator RTAC is a graphical, easy-to-use tool that helps users quickly and easily configure the SEL-3530 Real-Time Automation Controller (RTAC).
acSELerator Diagram Builder SEL-5035 Software is a Microsoft Windows application that enables the creation and management of HMI visualization projects for all of the RTACs in your system.
Improve productivity, manage device data, and collect data quickly and efficiently with Team Software.
The SEL-5073 synchroWAVe Phasor Data Concentrator Software provides phasor data concentration and archving for more than 500 phasor measurement units.
Quickly translate power system data into information with synchroWAVe Central.
synchroWAVe Event can plot relay oscillography, display phasors, and monitor digital status.
SEL-5630 Meter Reports enhances the visualization and analysis of data captured by SEL meters in your system.
Optimize outage management and improve underground reliability.
Quickly identify faults in transmission cable splices and communicate to line crews using the RadioRANGER.
Adds dial-up access to devices in harsh utility and industrial environments.
Use one pair of fibers for full-duplex serial communications plus IRIG-B time synchronization.