DS3800NSCD1B1C | GE Mark VIe Dual-Channel Serial Board

Description

Product Introduction (Anti-Template)

Two serial ports are all you need—but if those two ports fail due to a surge or vibration, you’re dead in the water. The DS3800NSCD1B1C addresses that by building the dual-channel NSCD in a ruggedized package. The “1B” revision upgrades the surge suppression from 600W to 1.5kW TVS diodes; the “1C” revision adds reinforced through-hole terminal anchoring and a high-Tg PCB for extended temperature operation.

What you get is a compact two-channel board that’s built to survive in harsh industrial environments—outdoor enclosures, turbine decks, and remote stations. The dual-channel form factor makes it perfect for applications where you only have one or two serial connections (a DCS link and a vibration monitor, for instance), but you can’t afford to lose them. A natural gas compression station replaced their standard NSCD boards with the 1B1C version after losing two boards to lightning-induced surges. The upgraded surge suppression has made the difference—they haven’t lost a board since.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

What’s the difference between the 1B1C and the standard NSCD?
Two upgrades:

• The “1B” revision upgrades the surge suppression from 600W to 1.5kW TVS diodes—more than double the clamping capability.
• The “1C” revision adds through-hole anchoring to the terminal blocks, high-Tg PCB material, and extends the operating temperature from -25°C to +70°C.

The channel count, protocol support, and isolation rating (2500V) are the same.

Is the 2500V isolation on the 1B1C “reinforced” isolation?
Yes, the 1B1C uses reinforced optical isolation—the same 2500V rating as the standard NSCD, but with enhanced creepage and clearance distances (4mm) to meet the requirements of the ruggedized design. The components used are also selected for extended temperature range.

Can I mix 1B1C boards with standard NSCD boards in the same rack?
Yes, they’re mechanically and electrically compatible. The 1B1C uses the same 50-pin header and mounting holes as the standard NSCD. You can mix them without issues.

What’s the maximum baud rate?
115.2 kbps for RS-232, up to 1 Mbps for RS-485/RS-422.

How do I wire RS-485 on the 1B1C?
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.

Can I hot-swap the 1B1C?
No. Power down the rack before swapping.

What’s your test procedure?
Our inbound test:

• Visual: inspect terminal blocks, optical isolators, and TVS diodes for damage.
• Isolation: 2500V DC between field and module sides—must exceed 20MΩ.
• Surge test: apply a 1.5kV surge—verify the TVS diodes clamp without damage.
• Communication test: loopback at 115.2 kbps on all channels.
• Thermal cycling: -25°C to +70°C for 3 cycles while monitoring continuity.
• LED test: verify LEDs illuminate correctly.

We reject about 5% of inbound 1B1C boards—mostly for damaged TVS diodes or poor through-hole solder joints on the terminal blocks.

What’s the most common field issue?
Incorrect RS-485 termination. If you have more than two devices on an RS-485 bus, you need to enable termination resistors only at the physical ends of the bus. If you enable termination on a middle device or forget it at the end, signal reflections cause errors. The 1B1C’s enhanced surge protection won’t save you from termination issues. Check your bus configuration. Also, remember that RS-232 has a 50-foot (15-meter) cable limit—beyond that, use RS-485.

NI SCXI-1104C
GE D20-EME
TOSHIBA USIO21