Description
IS200WETBH1BAA Product Overview
The IS200WETBH1BAA is a 16-channel mixed-signal I/O termination board used inside GE Mark VI and Mark VIe Speedtronic turbine-control cubicles. It mounts on the VME backplane and interfaces field sensors (pressure transmitters, RTDs, thermocouples, servo-valve LVDTs) to the control processor by providing signal conditioning, A/D conversion, and 1500 V galvanic isolation.
The IS200WETBH1BAA is a 16-channel mixed-signal I/O termination board used inside GE Mark VI and Mark VIe Speedtronic turbine-control cubicles. It mounts on the VME backplane and interfaces field sensors (pressure transmitters, RTDs, thermocouples, servo-valve LVDTs) to the control processor by providing signal conditioning, A/D conversion, and 1500 V galvanic isolation.
In the control hierarchy the board sits at the “sensor-interface” layer: it burdens current loops, excites 3-/4-wire RTDs, cold-junction-compensates thermocouples, and streams 12-bit data at 100 Hz per channel to the CPU over the VME bus. An on-board 12-bit ADC and digital filter ensure <0.1 % accuracy, while TVS diodes and 50/60 Hz notch filters give IEEE C37.90.1 surge immunity—essential for turbine temperature, pressure, and position loops.
The board is normally paired with the IS215WETBH1AEC daughter card, which holds the ADCs and DSP, while IS200WETBH1BAA provides the termination, excitation, and surge protection. Because both cards are certified for Zone 2 and operate from 24 VDC without fans, they are accepted in gas-turbine, steam-turbine, and compressor-control skids worldwide.
IS200WETBH1BAA
Technical Specifications
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Model Number: IS200WETBH1BAA
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Manufacturer: General Electric
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Product Type: Mixed Analog / Digital I/O Terminal Board
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Channels: 16 configurable I/O points (analog or digital)
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Input Ranges: Voltage ±10 V, Current 0–20 mA / 4–20 mA, RTD (3-/4-wire), Thermocouple (J, K, T, E, etc.)
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Resolution: 12-bit A/D conversion
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Sampling Rate: 100 Hz per channel
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Cold-Junction Accuracy: ±0.5 °C (thermocouple mode)
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RTD Excitation: 1 mA constant-current source
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Surge Protection: TVS diodes, IEEE C37.90.1 compliant
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Noise Filtering: 50/60 Hz notch filters
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Isolation: 1500 V channel-to-ground
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Power Supply: 24 VDC logic (derived from backplane)
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Temperature: –40 … +70 °C operational; –40 … +85 °C storage
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Weight: ≈ 1.56 kg (3.4 lb)
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Certifications: CE, UL, RoHS, Zone-2 ready
IS200WETBH1BAA
Core Features & Customer Value
Multi-range 16-channel density – One board replaces separate voltage, current, RTD, and TC cards, freeing Mark VI slots and reducing spare-part count
Multi-range 16-channel density – One board replaces separate voltage, current, RTD, and TC cards, freeing Mark VI slots and reducing spare-part count
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12-bit, 100 Hz per channel – Delivers millisecond-level temperature or pressure updates for turbine protection loops without loading the main CPU
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Cold-junction & RTD on-board – On-chip CJC and 1 mA excitation eliminate external transmitters, saving panel space and wiring errors
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IEEE C37.90.1 surge immunity – TVS diodes and notch filters survive breaker-slam events common in power-plant switchyards
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Zone-2 / marine certified – Certified for Class I Div. 2 and offshore environments, allowing direct installation in hazardous-location turbine skids without additional purge systems
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Typical Applications
In combined-cycle power plants the IS200WETBH1BAA is installed in Mark VIe racks that monitor gas-turbine exhaust temperature (type-K thermocouples), bearing-metal temperature (3-wire RTDs), and fuel-pressure transmitters (4-20 mA). The 100 Hz update keeps overtemperature protection responsive while the 12-bit resolution resolves 0.1 °C changes
In combined-cycle power plants the IS200WETBH1BAA is installed in Mark VIe racks that monitor gas-turbine exhaust temperature (type-K thermocouples), bearing-metal temperature (3-wire RTDs), and fuel-pressure transmitters (4-20 mA). The 100 Hz update keeps overtemperature protection responsive while the 12-bit resolution resolves 0.1 °C changes
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In pipeline compressor stations the same board reads 4-20 mA from suction/discharge pressure transmitters and drives anti-surge valve position feedback, using the ±10 V range when magnetic amplifiers require a voltage reference
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Because the board is certified for marine environments, it is also used on off-shore platforms for well-head temperature and subsea pressure feedback without needing additional isolation barriers
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