html{display:none} SEL-3355 | Schweitzer Engineering Laboratories


The SEL-3355 is a versatile computing platform built to withstand harsh environments in utility and industrial applications. The SEL-3355 can be configured as a Blueframe application platform or an industrial computer running a Microsoft Windows or Linux OS. For the related Real-Time Automation Controller (RTAC) model, see the SEL-3555.

The SEL-3355 is a powerful rack- or panel-mount computing platform featuring an Intel Xeon quad-core 2.0 GHz or 2.8 GHz processor. The SEL-3355 can be ordered from the factory with SEL Blueframe, Microsoft Windows 10 IoT Enterprise, or Microsoft Windows Server OSs preinstalled. Operating system conversion kits are also available for upgrading existing hardware. Additionally, SEL network and serial port drivers are available to support the installation of third-party Linux OSs.

By using error-correcting code (ECC) memory and eliminating all moving parts, such as rotating hard drives and fans, SEL computing platforms achieve one of the highest mean time between failures (MTBF) ratings in the industry. Designed, manufactured, and tested to the same standards as our protective relays, every SEL computing platform comes with our industry-leading ten-year warranty and is made in the U.S.A.

SEL Computing Platform Comparison Table

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Blueframe—Improve your power system operational technology (OT) network management, simplify security patches, and ensure availability with the SEL Blueframe application platform. You can configure SEL computing platforms (SEL-3350, SEL-3355, and SEL-3360) with Blueframe to manage and operate SEL containerized applications, like the Data Management and Automation (DMA) applications.

Industrial Automation Platform—Deploy complete automation control and operator station functionality in a single package directly to the plant floor without the concern of environmental conditions. The SEL-3355 is a powerful and reliable computing platform that supports soft programmable logic controllers (PLCs) and operator HMI control engines. Design engineers can leverage virtual machine (VM) resources integrated into the chipset of SEL computing platforms to reduce project costs. SEL computing platforms are available with Xeon quad-core 2.0 GHz and 2.8 GHz processors to meet the needs of even the most demanding computing applications.

HMI Visualization, Monitoring, and Control—Make a secure system visualization, monitoring, and control point for your substation or plant. You can leverage CIS Security Benchmarks settings to meet NERC CIP and other industry compliance standards.

Information Processor: Data Concentrator/Protocol Converter—Collect and format relay data for legacy remote terminal units (RTUs), and send the data directly to SCADA systems using legacy protocols. You can leverage multiple paths for data access, collect data at one rate, and service them to any client via any supported protocol.

Centralized Authentication Server—Extend central authentication to your branch office or substation by logging in with enterprise credentials and using the same account throughout your network. You can set up role-based access controls and employ high-availability services for always-on service.

Original Equipment Manufacturer (OEM) Software Appliance—The SEL-3355 has the processing power and rugged hardware necessary for operating in critical infrastructure environments. Whether you are currently shipping a tough appliance or thinking about deploying your software as a dedicated appliance for rugged environments, consider the SEL-3355 to complement your solution.

Synchrophasor Archiver, Server, and Console—Install a single computing platform to concentrate, archive, and display synchronized phasor measurements from a wide area with SEL-5073 synchroWAVe Phasor Data Concentrator (PDC) Software. Implementing RAID capabilities provides the fastest and most reliable database storage.

Engineering Workstation—Meet or exceed IEEE 1613 and protective relay specifications for harsh environments with any SEL computing platform, made to withstand vibration, electrical surges, fast transients, and extreme temperatures. You can access the engineering workstation remotely and securely using Microsoft Windows Remote Desktop tunneled over IPsec or through Intel Active Management Technology (AMT) with remote KVM over IP.


    1. 1

      LED lamp test button

    2. 2

      Alarm and operational status LED indicators

    3. 3

      Ethernet port link status and network activity LEDs

    4. 4

      Serial port Transmit and receive LEDs

    5. 5

      Front heat sink and no fans or moving parts

    6. 6

      Up to four hot-swappable SSDs

    7. 7

      Hard disk drive activity LED

    8. 8

      Three programmable bicolor LEDs

    9. 9

      Two front-panel USB 3.1 ports

    1. 1

      Rear heat sink

    2. 2

      Two DVI-D ports

    3. 3

      Two high-speed Gigabit Ethernet ports

    4. 4

      Four USB 3.1 ports

    5. 5

      Line-in, line-out, and microphone jacks

    6. 6

      Two built-in BIOS-configurable EIA-232 ports with +5 V on Pin 1

    7. 7

      DisplayPort monitor connection technology

    8. 8

      Form C alarm contact output

    9. 9

      Up to five expansion slots: one legacy PCI, two x1 PCIe, and two x4 PCIe

    10. 10

      Dual hot-swappable power supplies



Industrial and substation automation and computing systems require 24/7 availability and ease of service when necessary. In order to address these needs, SEL computing platforms employ “server class” reliability, availability, and serviceability (RAS) attributes.

SEL designs, manufactures, and tests every computing platform in house. Our computing platforms have one of the highest MTBF ratings in the industry, and they are backed by a ten-year warranty.

Designed to keep your system operational for longer periods, the SEL-3355 can be optioned with dual load-sharing power supplies and a RAID-configurable four-bay SSD enclosure. SEL computing platforms also feature the unique SEL system monitor (SysMon) with a watchdog timer.

Intel AMT allows you to view logs for evaluation and service even when the unit is powered off. You can reboot into another OS for diagnostics or to batch software and then bring the system back online, all remotely. Additionally, SEL SysMon logs events specific to the installed system to aid in quick recovery.

Robust Hardware Design
SEL computing platforms are designed for maximum reliability, with no fans or moving parts, and are backed by a ten-year warranty. The SEL-3355 has a durable power supply, an advanced thermal management system, error-correcting memory, and single-level cell (SLC) SSDs to provide reliable operation in the harshest environments.

Reliable Operation—Meets IEEE 1613, IEEE C37.90, and IEC 60255 Protective Relay Standards
Install the SEL-3355 in harsh environments. It is designed to withstand 15 kV electrostatic discharge, fast transients, radiated emissions, up to 15 g shock, seismic and sustained vibration, overcurrent, dielectric strength, and pulse magnetic field disturbances.

Wide-Range Power Supply
The power supply supports 120/240 Vac or 125/250 Vdc. You can choose two power supplies and use one with 120 Vac and the other with 125 Vdc for backup.

Watchdog Functionality
Monitor and alarm for numerous system services and conditions with an embedded controller that provides an extra level of computer system reliability. The embedded controller includes a programmable system monitor interface and alarm configuration.

High-Performance Intel Xeon Quad-Core Processors
The SEL-3355 features Intel multicore processors with Intel vPro technology and up to 64 GB of ECC RAM, providing the power you need for any application.

Multiple I/O Ports
Directly connect to various local peripherals and high-speed network interfaces with two Ethernet ports, audio I/O, six USB 3.1 ports, three digital video ports, and two serial ports.

Flexibility With PCI Slots
Four PCI Express and one legacy PCI expansion slots let you add additional serial ports, Ethernet ports, I/O, or other PCI Express cards that your application requires.

Operating System Choices
You can purchase the SEL-3355 as hardware-only or configure it to run a variety of Linux and Microsoft Windows OSs to provide extreme flexibility and functionality along with enhanced security features.

Large Storage Capacity
With a four-drive SSD bay, you can create one large volume or configure a typical RAID system that provides redundant and more reliable storage. The following SSD options are available:

  • SLC for the highest endurance and reliability
  • Pseudo-SLC (pSLC) for a higher capacity but reduced endurance
  • 3D triple-level cell (TLC) for the highest capacity and a lower cost but reduced endurance

OS Options

The SEL-3355 supports various OS installation options. You can purchase the computing platform as hardware without an OS installed, providing flexibility to install your own custom OS image.

SEL computing platforms support several factory-installed configurations, including the Blueframe application platform and Microsoft Windows 10 IoT Enterprise and Windows Server OSs. SEL network and serial port drivers are available to support the installation of third-party Linux OSs.

The SEL-3355 can be converted between Windows and Blueframe OSs, offering the flexibility to upgrade existing hardware. Conversion kits also support the RTAC OS. For more information about OS conversion kits, contact your local sales or customer service representative.


  • RTAC
  • Blueframe*

Supported third-party OSs:

  • Microsoft Windows 8
  • Microsoft Windows 10*
  • Microsoft Windows Server*
  • Red Hat Enterprise Linux (RHEL)
  • CentOS Linux
  • Ubuntu LTS Linux
  • SUSE Linux
  • VMware ESXi

*Factory-orderable OS.


Xeon quad-core 2.0 GHz is standard; Xeon quad-core 2.8 GHz is optional.


4 GB of ECC RAM is standard. Choose up to 64 GB of ECC RAM.

Storage Options

Choose from single-level cell (SLC), pseudo-SLC (pSLC), or 3D triple-level cell (TLC) industrial temperature-rated and conformal-coated SSDs from 32 GB to 1,920 GB.

Power Supply

Choose one or two hot-swappable power supplies from the available high-voltage (125–250 Vdc/120–240 Vac) and low-voltage (48 Vdc) options.

PCIe Expansion Cards

Conformal Coating

Protect equipment from harsh environments and airborne contaminants, such as hydrogen sulfide, chlorine, salt, and moisture.


A number of peripherals (e.g., mouse, keyboard, and touchscreen monitor) are available direct from SEL as accessories. Accessories should not de-rate the operational specifications of the product, such as temperature, shock, vibration, etc.

For more information, please reference the Computing Platform Accessories Catalog.


SEL Automation Controllers Defy Brazil’s Heat

Introducing SEL-3355

SEL-3355 Thermal Management

SEL-3355 Design and Testing

The Firmware IDs for older versions of the firmware can typically be found in Appendix A of the instruction manual.

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3355 - Software Tab


Drivers, Firmware, and System Software

SEL offers a wide range of drivers, firmware, and system software for the SEL-3350, SEL-3355, and SEL-3360 computing platforms and SEL-3390 expansion cards.

Visit the SEL Software Downloads page to find available downloads for SEL computing platforms and expansion cards.

SEL-5815 PRP Driver for Windows

SEL-5815 adds Parallel Redundancy Protocol (PRP) support compliant with IEC 62439-3 to SEL computing platforms.

Learn more and download on the SEL-5815 product page.

SEL Backup and Recovery Tool (BaRT)

Use SEL BaRT to quickly and easily create a snapshot of your computing platform’s operating system and configuration. SEL BaRT was designed specifically for SEL’s computing platform line and takes advantage of each platform’s features.

Learn more and download here.

Cable Part NumberTerminationLengthNotesSchematic
C605ADB-9 Male1 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ-45 M/DB-9 M, IRIG-B, Hardware Flow Control)View

DB-9 Male1 to 100 ftSEL RJ45 Serial Cable to SEL DNP (RS-232, DTE-DTE, RJ45 M/DB-9 M, IRIG-B) 

DB-9 Female1 to 6 ftSEL RJ45 Serial Adapter Cable (RS-232, DTE-DCE, RJ45 M/DB-9 F, IRIG-B, Pin 1 Power, Hardware Flow Control) View
C478N**DB-9 Female + BNC1 to 6 ftSEL RJ45 Serial Adapter Cable (RS-232, DTE-DCE, RJ45 M/DB-9 F/BNC F, IRIG-B, Pin 1 Power, Hardware Flow Control)View
C605DB-9 Male1 to 6 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ45 M/DB-9 M, IRIG-B, Pin 1 Power, Hardware Flow Control)View
C605R*DB-9 Male1 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ45 M/DB-9 M, IRIG-B, Hardware Flow Control) View
C477DB-9 Male1 to 150 ftSEL RJ45 Serial Cable to GE DNP I/O (RS-485, RJ45 M/DB-9 M)View
C607Tinned Wires1 to 330 ftSEL RJ45 Serial Cable for Terminal Server (RJ45 M/Tin Wires)View
C616DB-9 Male1 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DCE, RJ45 M/DB-9 M, IRIG-B, Pin 1 Power, Hardware Flow Control)View
C629ARJ451 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ45 M/RJ-45 M, IRIG-B)View
C629R*RJ451 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ45 M/RJ-45 M, IRIG-B, Hardware Flow Control)View
C659DB-9 Male + BNC1 to 100 ftSEL RJ45 Serial Cable (RS-232, DTE-DTE, RJ45 M/DB-9 M/BNC M, IRIG-B, Pin 1 Power, Hardware Flow Control)View
C972BNC1 to 130 ftSEL RJ45 Serial Cable (Modulated IRIG, RJ45 M/BNC M)View

*This cable is double-shielded (contains both foil and braid shields) with the shield connected to the shell at both ends of the cable for improved immunity to electrical disturbances that can cause data loss.

**These cables are for connecting to existing SEL serial cables with a DB-9 connector and fiber-optic SEL-2800 series transceivers.

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