Description
DS3800HITA1F1F: Product Overview
The DS3800HITA1F1F is a daughterboard-grade high-speed pulse input card that plugs onto a motherboard carrier inside the GE Speedtronic Mark IV rack. It sits electrically between field pulse sources and the central CPU, converting zero-to-100 kHz pulse trains from magnetic speed pickups, shaft encoders, and turbine-flow transmitters into 12-bit count/frequency words that the CPU uses for speed PID, acceleration limiting, and flow summation. 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 overspeed and flow-protection loops.
The board belongs to the DS3800 daughterboard architecture, allowing hot-swap replacement without rewiring the turbine deck. Gold-plated edge fingers, conformal coat, and IEEE 344 seismic qualification ensure 25-year service life in high-vibration, salt-fog, or coal-dust environments.
DS3800HITA1F1F
DS3800HITA1F1F: Technical Specifications
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Model Number: DS3800HITA1F1F
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Manufacturer: General Electric (GE)
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Product Type: High-Speed Pulse / Timing & Frequency Input Board
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System Compatibility: Speedtronic Mark IV (6BA06 slot)
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Input Type: Digital pulses from magnetic pickups, encoders, flow meters
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Max Input Frequency: 100 kHz (zero-velocity to overspeed)
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Counter Resolution: 12-bit (4096 counts)
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Input Threshold: 50 mV to 120 V p-p (field-adjustable)
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Isolation: 1500 V AC channel-to-ground, 500 V channel-to-channel
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Output Format: 12-bit parallel count + frequency word to VME bus
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Filter: 2-pole Butterworth, 10 Hz–10 kHz jumper-selectable
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Connectors: 20-pin ribbon (field side) + VME edge fingers (back-plane side)
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Power Rails: +5 V logic, ±15 V analog, <1 W per channel
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Indicators: Green = pulse active, Red = fault / over-range
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Operating Temperature: -20 °C to +70 °C; Storage: -55 °C to +125 °C
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Certifications: CE, RoHS, IEEE 344 seismic, SIL-2 suitable
Core Features & Customer Value
Microsecond-Accurate Speed Measurement
The 100 kHz capability and <1 µs edge-to-edge jitter enable zero-velocity through overspeed (120 %) tracking—mandatory for grid-code frequency-response and overspeed-protection compliance. You get deterministic timing even during cold crank or rapid load rejection.
The 100 kHz capability and <1 µs edge-to-edge jitter enable zero-velocity through overspeed (120 %) tracking—mandatory for grid-code frequency-response and overspeed-protection compliance. You get deterministic timing even during cold crank or rapid load rejection.
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-Calibratable Without Software
On-board threshold pot and jumper-selectable filter corner let you match pickup sensitivity or reject gear-mesh noise on the turbine deck using only a screwdriver and a scope. This eliminates the need for a laptop or OEM service call when you swap sensors or change cable runs.
On-board threshold pot and jumper-selectable filter corner let you match pickup sensitivity or reject gear-mesh noise on the turbine deck using only a screwdriver and a scope. This eliminates the need for a laptop or OEM service call when you swap sensors or change cable runs.
Surge-Hardened for Harsh Sites
TVS diodes on every input clamp >500 V spikes from lightning, VFD switching, or exciter flash-over. The 1500 V galvanic 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 on every input clamp >500 V spikes from lightning, VFD switching, or exciter flash-over. The 1500 V galvanic 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.
DS3800HITA1F1F
Typical Applications
Gas Turbine Speed & Acceleration Control
In large combined-cycle plants, DS3800HITA1F1F is widely used to condition magnetic-pickup signals from the auxiliary gear. The 12-bit resolution and <5 µs settling time allow the CPU to detect sub-rpm speed changes that precede overspeed events, enabling predictive shutdowns that avoid thermal damage.
In large combined-cycle plants, DS3800HITA1F1F is widely used to condition magnetic-pickup signals from the auxiliary gear. The 12-bit resolution and <5 µs settling time allow the CPU to detect sub-rpm speed changes that precede overspeed events, enabling predictive shutdowns that avoid thermal damage.
Steam Turbine Flow & Power Measurement
The card’s 0.1–5 kHz range makes it the preferred interface for turbine-meter pulse trains on steam lines. During load rejection, the deterministic 100 kHz update rate preserves flow transients while the 100 Hz filter rejects piping vibration, maintaining ±0.1 % flow accuracy.
The card’s 0.1–5 kHz range makes it the preferred interface for turbine-meter pulse trains on steam lines. During load rejection, the deterministic 100 kHz update rate preserves flow transients while the 100 Hz filter rejects piping vibration, maintaining ±0.1 % flow accuracy.
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 <1 W and continues to deliver accurate counts when external transmitters are powered from station DC.
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 <1 W and continues to deliver accurate counts when external transmitters are powered from station DC.
