Description
DS3800HNMB1B1D: Product Overview
The DS3800HNMB1B1A is a daughterboard-grade null-modem communication card that plugs onto a motherboard carrier inside the GE Speedtronic Mark IV rack. It acts as the low-level serial interface between the central CPU and external devices—typically a local HMI, programming laptop, or third-party SCADA—providing isolated RS-232/RS-485 half-duplex data exchange without requiring a separate comm module. Because it is hardware-deterministic (no firmware), the card delivers bit-exact timing across all three legs of a TMR string, making it suitable for SIL-2 / API 670 diagnostic and programming links.
The board belongs to the DS3800 daughterboard architecture, allowing hot-swap replacement without rewiring the turbine deck. Gold-plated edge fingers, conformal coat, and –20 °C to +70 °C rating ensure 25-year service life in coal-dust, salt-fog, or high-vibration environments.
DS3800HNMB1B1A
DS3800HNMB1B1A: Technical Specifications
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Model Number: DS3800HNMB1B1A
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Manufacturer: General Electric (GE)
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Product Type: Null-Modem Communication Card
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System Compatibility: Speedtronic Mark IV (6BA01 slot)
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Comm Interfaces: RS-232 / RS-485 half-duplex (jumper-selectable)
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Data Rate: Up to 115.2 kbps (jumper-selectable baud)
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Isolation: 1500 V AC board-to-ground, 500 V channel-to-channel
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Field Supply: 24 V DC (from rack back-plane)
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Connectors: 20-pin ribbon (CPU side) + 9-pin D-sub (field side)
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Indicators: Green = RX active, Red = TX / collision
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Operating Temperature: -20 °C to +70 °C; Storage: -40 °C to +85 °C
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Certifications: CE, RoHS, IEEE 344 seismic, SIL-2 suitable
Core Features & Customer Value
Deterministic, Hardware-Only Serial Link
No firmware means every bit transition is bit-exact across all three TMR legs, eliminating timing skew that could corrupt diagnostic downloads or remote-operator commands during a CPU reboot.
No firmware means every bit transition is bit-exact across all three TMR legs, eliminating timing skew that could corrupt diagnostic downloads or remote-operator commands during a CPU reboot.
Hot-Swap Ready
Daughterboard form allows you to extract and insert the card while the turbine remains on-line (provided the carrier is in a TMR string). Mean-time-to-repair is <5 minutes, so you avoid forced outages and start-up delays.
Daughterboard form allows you to extract and insert the card while the turbine remains on-line (provided the carrier is in a TMR string). Mean-time-to-repair is <5 minutes, so you avoid forced outages and start-up delays.
Field-Configurable Without Software
Jumper-selectable baud rate, protocol, and termination allow you to match plant HMI or programming tools using only a tweaker and the silk-screen legend—no laptop or OEM service call required.
Jumper-selectable baud rate, protocol, and termination allow you to match plant HMI or programming tools using only a tweaker and the silk-screen legend—no laptop or OEM service call required.
Surge-Hardened for Turbine Deck
TVS diodes and differential line drivers clamp >500 V spikes from lightning, VFD switching, or exciter flash-over. The 1500 V isolation barrier prevents ground-fault currents from propagating into the low-voltage CPU domain, extending card life beyond 25 years in coal-dust, salt-fog, or high-vibration environments.
TVS diodes and differential line drivers clamp >500 V spikes from lightning, VFD switching, or exciter flash-over. The 1500 V isolation barrier prevents ground-fault currents from propagating into the low-voltage CPU domain, extending card life beyond 25 years in coal-dust, salt-fog, or high-vibration environments.
DS3800HNMB1B1A
Typical Applications
Gas Turbine Local HMI & Programming Port
In large combined-cycle plants, DS3800HNMB1B1A is widely used as the local RS-485 port for Frame 7/9 heavy-duty units, allowing engineers to connect a laptop or local pendant for ToolboxST diagnostics, firmware reloads, or real-time trending without entering the turbine hall.
In large combined-cycle plants, DS3800HNMB1B1A is widely used as the local RS-485 port for Frame 7/9 heavy-duty units, allowing engineers to connect a laptop or local pendant for ToolboxST diagnostics, firmware reloads, or real-time trending without entering the turbine hall.
Steam Turbine Remote I/O Bridge
The card’s half-duplex RS-485 capability makes it the preferred interface for remote I/O clusters, generator vibration monitors, or steam-valve positioners mounted hundreds of metres from the control room, maintaining <0.1 % bit-error rate over 500 m of shielded pair.
The card’s half-duplex RS-485 capability makes it the preferred interface for remote I/O clusters, generator vibration monitors, or steam-valve positioners mounted hundreds of metres from the control room, maintaining <0.1 % bit-error rate over 500 m of shielded pair.
Island-Mode & Black-Start Sites
On offshore platforms or remote peaking plants, the –20 °C rating and conformal coat allow the card to run without HVAC. Battery-backed operation is supported because the card draws <0.3 W and continues to relay critical start-up commands when the plant is islanded from the grid.
On offshore platforms or remote peaking plants, the –20 °C rating and conformal coat allow the card to run without HVAC. Battery-backed operation is supported because the card draws <0.3 W and continues to relay critical start-up commands when the plant is islanded from the grid.
