DS3800NSCD | OEM GE Turbine Control Serial Communication Board

Description

Product Introduction (Anti-Template)

A serial communication board with two channels is sometimes all you need—you don’t always need the four channels of the NSCC. The DS3800NSCD is GE’s dual-channel serial termination board for the Mark VIe system, providing two isolated, software-configurable serial ports for connecting to plant-wide networks, PLCs, vibration monitors, and other serial devices.

What you get is a board with a smaller footprint (half-height) and a lower channel count, but the same 2500V optical isolation and surge suppression as the larger NSCC. It’s the right choice when you have one or two serial connections and you don’t want to pay for four unused channels. The board supports RS-232, RS-485, and RS-422—software-configurable, just like the NSCC. A food processing plant with a Mark VIe controlling a cogeneration turbine only needed serial connection to a building management system and a flow computer. The two-channel NSCD was a perfect fit—they got the isolation and protection they needed without the cost of a four-channel board.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

What’s the difference between the NSCD and the NSCC?
Channel count. The NSCC has four serial channels; the NSCD has two. They share the same isolation rating, same protocol support, same surge protection, and same half-height form factor. The NSCC is for applications requiring more serial connections; the NSCD is for applications where two channels are sufficient.

Can I upgrade an NSCD to an NSCC if I need more channels?
Yes, the boards share the same mounting holes and 50-pin connector. If you need more channels, you can swap the NSCD for an NSCC without changing the rack or wiring. You’ll need to wire the additional two channels from the NSCC’s terminal blocks, but the electrical connection is compatible.

What protocols does the NSCD support?
RS-232, RS-485, and RS-422—each channel is independently software-configurable. You can have RS-232 on channel 1 and RS-485 on channel 2, or any other combination.

What is the maximum baud rate?
115.2 kbps for RS-232, up to 1 Mbps for RS-485/RS-422. The board doesn’t impose a limit beyond what the module supports.

How do I wire RS-485 on the NSCD?
Use the terminal blocks (A, B, shield). Enable the 120Ω termination resistor via jumper if this board is at the end of the RS-485 bus. Use shielded twisted-pair cable with the shield grounded at one end only.

What’s the isolation rating?
2500V optical isolation per channel. That’s enough to break ground loops and protect the Mark VIe system from surges.

Can I hot-swap the NSCD?
No. The board is connected to live serial devices. Pulling it while powered could damage the communication module or the field device. Power down the rack, swap, and power back up.

What do the LED indicators show?
Green: channel active. Yellow: data transmission (TX). Red: data reception (RX). Useful for quick diagnostics.

What’s your test procedure?
Our inbound test:

• Visual: inspect connectors, bent pins, and TVS diodes for damage.
• Isolation: 2500V DC between field and module sides—must exceed 10MΩ.
• Surge test: apply a 1kV surge—verify the board survives without damage.
• Communication test: loopback at 115.2 kbps on all channels.
• LED test: verify LEDs illuminate correctly.

We reject about 4% of inbound boards—mostly for damaged TVS diodes or poor solder joints.

What’s the most common field issue?
Using RS-232 when you meant RS-485, and vice versa. The board supports both, but the connector is different—RS-232 uses the DB-9 connector, RS-485/RS-422 uses the terminal blocks. We’ve seen plants wire an RS-485 device to the DB-9 connector and wonder why it doesn’t work. Choose the correct connector for your protocol. Also, remember that RS-232 has a limited cable length (50 feet maximum)—RS-485 can go much farther (up to 4,000 feet at lower baud rates).

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