DS3800NSFC1J | Replacement for NSFC Fiber Optic Interface Board

Description

Product Introduction (Anti-Template)

Copper serial links that get fried by lightning or corrupted by ground loops are the reason fiber exists. The DS3800NSFC1J is GE’s fiber optic termination board for the Mark VIe system, converting electrical serial signals to optical signals for transmission over fiber optic cable. It gives you two channels of fiber optic communication—perfect for connecting to remote DCS systems, PLCs, or data historians located in different buildings or across a plant site.

What you get is complete electrical isolation—there’s no copper path for ground loops or surges to travel. The fiber optic link is immune to EMI, lightning, and ground potential differences. Compared to copper serial links (RS-232/RS-485), fiber optic gives you longer distances (up to 2km) and complete immunity to noise. A steel mill in Indiana had been losing RS-485 links to their DCS every time a large motor started—the EMI was overwhelming the copper cable. They swapped to fiber optic using the NSFC1J and haven’t lost a link in three years. The fiber connection solved the problem at its root.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

What’s the difference between the NSFC1J and a standard copper serial board?
Fiber optic vs. copper. The NSFC1J uses fiber optic transceivers to transmit signals over optical fiber, providing complete electrical isolation and immunity to EMI, lightning, and ground loops. Copper boards (NSCD/NSCC) use electrical signals over copper wire and are susceptible to noise and ground loops. Fiber is the better choice for long distances or noisy environments.

What fiber optic cable do I need?
The NSFC1J uses 50/125µm or 62.5/125µm multimode fiber optic cable with ST connectors. The 850nm wavelength supports up to 2km. Use duplex fiber (two strands—one for TX, one for RX). The distance is limited by the I/O module’s optical power budget, not the termination board.

Can I use single-mode fiber with the NSFC1J?
No, the NSFC1J is designed for multimode fiber. The transceivers are not compatible with single-mode fiber. If you need single-mode, you’ll need a different fiber optic converter or I/O module.

How do I connect the NSFC1J to a serial device?
The NSFC1J connects to the serial communication module (the I/O module) via the 50-pin header. The I/O module converts the electrical serial signal to optical and transmits it over fiber. At the other end, you’ll need another fiber optic converter or a device with a fiber optic serial port. The NSFC1J is the termination board inside the Mark VIe rack.

What’s the maximum distance?
Up to 2km for 850nm multimode fiber. The actual distance depends on the fiber quality and the I/O module’s optical power. The NSFC1J itself doesn’t limit the distance—the transceivers on the I/O module do. The board just provides the physical connection.

Can I hot-swap the NSFC1J?
No. Power down the rack before swapping.

What do the LED indicators show?
Green: channel active. Yellow: data transmission (TX). Red: data reception (RX). The LEDs are useful for quick diagnostics—you can see if data is flowing.

What’s your test procedure?
Our inbound test:

• Visual: inspect fiber optic connectors (ST) for damage or contamination. Clean with a fiber optic cleaning pen if needed.
• Optical power test: verify the board passes the optical signal through without significant loss.
• Communication test: loopback at 115.2 kbps over a 10m fiber patch cable.
• LED test: verify LEDs illuminate correctly.

We reject about 3% of inbound NSFC boards—mostly for contaminated or damaged fiber connectors. The ST connectors are sensitive to dirt and damage.

What’s the most common field issue?
Dirty or damaged fiber connectors. A speck of dust on an ST connector can attenuate the signal enough to cause communication errors. Clean the connectors with a fiber optic cleaning pen or lint-free wipes before connecting. Also, ensure the fiber cable is not bent tighter than the minimum bend radius (typically 25mm for 62.5/125µm fiber)—a tight bend can cause signal loss. Finally, make sure you’re using duplex fiber and not simplex—the NSFC uses separate TX and RX fibers.

TRICONEX 3625
GE SR469-P5-HI-A20-E
ABB CI855K01
TRICONEX 3805E
MOTOROLA MVME162PA-344SE