Gigabit Ethernet Card With Integrated Relay Alarms to Indicate Fiber and Copper Link States

Gigabit Ethernet SFP
Gigabit Ethernet SFP

The Gigabit Ethernet with Alarms Fiber Link Cards extend Ethernet over fiber optic cable. They are hardened for utility use in substations and other critical applications. These cards operate over a wide temperature range and have been designed to provide reliability in harsh environments.

Common applications include extending Ethernet over fiber for the benefit of electrical isolation, to achieve long distances, or to reduce EMI through noisy environments. These cards are compatible 10/100/1000 speed Ethernet circuits and offer two relay alarms representing the fiber and copper port link statuses. The relays assist with diagnosing where a problem may exist in installation and are useful in remote locations where remote monitoring is necessary.

RLH Fiber Link Cards are designed and Made in the USA, and are covered by our Limited Lifetime Warranty.


  • Wide operating temperature range
  • -40°C to +70°C (-40°F to +158°F)
  • Extends Ethernet both short and long distances with SFPs
  • Dual Rate SFP Port – 100Mbps & 1Gbps
  • Copper link state relay alarm
  • Fiber link state relay alarm
  • Uses 24~48VDC local power
  • Critical, high voltage, remote or unmanned locations operating 24/7/365
  • Fiber Link Card is compatible with RLH Card Housings
  • Limited Lifetime Warranty
  • Made in USA

Please see the product User Guide for the complete list of specifications

Data Process:
Store & Forward, CSMA/CD

Ethernet Ports:
(1) 10/100/1000 Mbps
(1) SFP Slot, Dual Rate, accepts 100 or 1000 Mbps speed modules

Ethernet Interface:
Supports Jumbo Frames, Auto MDI/MDI-X, Auto-Negotiation

DIP Switches:
1 – LFP (Link Fault Pass) Enable/Disable
2 – SFP 1000Mbps / SFP 100Mbps

Contact Rating:
60Vp, 24Vac, 1Arms, 1Adc

Relay Switching Speed:
5mS (NC,NO)

Alarm Response Time:
5 Seconds (on link loss or link established)

Mounting Style:
Standard RLH Card Form Factor, For use with RLH Card Housings

Operating Temperature:
-40°F to 167°F (-40°C to 75°C)

Powering Requirement:
24~48VDC (2 position pluggable terminal block), Not polarity sensitive

Maximum Power Consumpion:
8 Watts

General Information

Status and Activity LED Display
Status and Activity LED Display


Lead Time: 1 to 2 Weeks*

For product questions, volume pricing and/or delivery outside of the US and Canada, please contact sales.


Gigabit Ethernet SFP

Short descriptionPart numberPrice
GIGABIT Ethernet Card, SFP, with Link Fault Alarm RelaysEG4-SFP-1$1,190.00

*Lead times are estimates and may vary. You will be contacted within 1 business day to go over the details of your order. If you require a specific date, let us know!
*Days = Business Days

WarningWarning: This product can expose you to chemicals including arsenic, which is known to the State of California to cause cancer. For more information, go to

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