GE IS200 Series Modules | IS200TRLYH1BHH Relay Terminal Board

Technical Dossier

Product Details And Specifications

GE IS200 Series: Comprehensive Module Range and Technical Overview

The GE IS200 series is the core I/O and terminal board platform of the GE Mark VI Turbine Control System, one of the most widely deployed distributed control architectures in global heavy industry. Mark VI and its IS200-series hardware are installed across gas turbine power plants, combined-cycle facilities, nuclear auxiliary systems, petrochemical complexes, and offshore oil & gas platforms. The platform's modular backplane architecture allows independent replacement of I/O boards, relay terminal boards, and communication adapters without full system shutdown, a critical requirement in continuous-process industries where unplanned outages carry costs measured in hundreds of thousands of dollars per hour. The IS200 series remains the dominant spare parts category for GE Frame 6B, 7E, 7EA, 9E, and LM-series turbine fleets operating worldwide.

The Evolution of IS200 Architecture

The IS200 platform was introduced alongside the Mark VI control system in the mid-1990s as a successor to the Mark V (IS3xx-series) hardware. Early IS200 boards used VME-compatible backplane signaling and relied on dedicated IONET and ARCNET communication buses for controller-to-I/O data exchange. The architecture was designed around triple-redundant (TMR) and simplex (S) controller configurations, with each I/O board capable of operating in either mode depending on the application criticality.

Between 2000 and 2010, GE introduced revised board revisions (denoted by suffix letters such as A, B, C, H) that addressed field-reported issues with relay contact ratings, analog signal conditioning accuracy, and backplane connector wear. The H-suffix revision, as found in the IS200TRLYH1BHH, represents a mature, field-proven hardware generation with improved relay coil drive circuitry and enhanced EMI filtering on terminal inputs.

From approximately 2012 onward, GE began transitioning new turbine installations to the Mark VIe platform (IS420-series boards), which uses Ethernet-based IONET and supports IEC 61850 communication. However, the installed base of Mark VI systems running IS200-series hardware remains enormous. GE and authorized service providers confirmed continued spare parts support through at least 2030, and the aftermarket supply chain — including DriveKNMS — provides sourcing for boards that have reached end-of-manufacture status at GE's Greenville, SC facility.

IS200 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced IS200-series modules. Each entry reflects the board's primary functional role within the Mark VI control architecture.

Relay Output & Terminal Boards

• IS200TRLYH1BHH: Relay terminal board, 16-channel discrete output, Mark VI TMR/simplex compatible, field-side relay interface for trip and alarm circuits.
• IS200TRLYH1B: Relay terminal board base revision; functionally equivalent to H1BHH with earlier-generation relay coil drivers.
• IS200TRLYS1B: Simplex-rated relay terminal board variant; reduced channel redundancy for non-critical output loops.

Analog I/O Boards

• IS200VAICH1B: Analog input board, 16-channel, 4–20 mA / 0–10 V configurable, used for process variable acquisition (pressure, temperature, flow).
• IS200VAOCH1B: Analog output board, 8-channel, 4–20 mA, drives control valves and positioners.
• IS200VTCCH1B: Thermocouple input board, 12-channel, supports J, K, T, E, R, S, B type thermocouples with cold-junction compensation.
• IS200VRTDH1B: RTD input board, 12-channel, 2/3/4-wire PT100/PT1000 compatible, used for bearing and winding temperature monitoring.

Digital I/O Boards

• IS200VDIAH1B: Discrete input board, 24-channel, 24 VDC / 125 VDC selectable, used for limit switches, valve position feedback, and protective relay contacts.
• IS200VDOAH1B: Discrete output board, 16-channel, solid-state output drivers, used for solenoid valve and annunciator control.
• IS200EDCFH1A: DC feedback input board; captures generator excitation and field current signals for AVR integration.

CPU & Controller Boards

• IS200UCVEH2A: Mark VI main controller board (UCVE), dual-processor architecture, hosts turbine control application software and manages IONET communication.
• IS200UCVEH2B: Revised UCVE controller with expanded flash memory and updated firmware support for GE ToolboxST configuration environment.
• IS200EPDMH1B: Ethernet-based process data module; bridges legacy IONET I/O to Ethernet backbone for historian and SCADA integration.

Power Supply Boards

• IS200EPSMH1A: Power supply module, 28 VDC regulated output, supplies backplane and I/O board logic rails within the Mark VI I/O enclosure.
• IS200BPPBH2B: Backplane power and protection board; distributes regulated DC to all slots and provides overcurrent protection per channel.

Communication & Network Adapters

• IS200ECTBH1A: Ethernet communication terminal board; provides RJ-45 interface for ToolboxST engineering workstation connectivity.
• IS200STCIH1B: Serial communication interface board; supports RS-232/RS-485 for legacy MODBUS RTU integration with third-party devices.

Sourcing Hard-to-Find & Obsolete IS200 Parts

GE formally discontinued manufacture of several IS200-series boards between 2018 and 2024 as production shifted to the Mark VIe IS420 platform. Boards including the IS200TRLYH1BHH, IS200VAICH1B, and IS200UCVEH2A are no longer available through GE's standard distribution channel and must be sourced from the secondary market.

DriveKNMS maintains a dedicated inventory of IS200-series boards sourced from decommissioned turbine control panels, authorized surplus dealers, and controlled-environment storage facilities. All boards are catalogued by part number, revision suffix, and firmware version where applicable. For operators running Mark VI systems beyond their original design life, DriveKNMS provides multi-year supply agreements that guarantee minimum stock levels for critical spare categories, eliminating the risk of a single-board failure causing extended forced outage.

Customers requiring cross-reference support — for example, identifying whether an IS200TRLYH1B can substitute for an IS200TRLYH1BHH in a specific rack slot — can submit their panel configuration data to the DriveKNMS technical team for compatibility verification prior to purchase.

Quality Control for the IS200 Range

IS200-series boards present specific test challenges due to their mixed-signal architecture: relay output boards such as the IS200TRLYH1BHH combine low-voltage logic circuitry with relay coils rated for 125 VDC contact switching, requiring isolation testing at both signal and power levels. DriveKNMS applies the following test protocol to all IS200 boards prior to shipment:

• Visual inspection under 10× magnification: solder joint integrity, relay contact condition, backplane connector pin straightness, and conformal coating coverage.
• Powered functional test: board is installed in a Mark VI-compatible test rack and exercised through all I/O channels using GE ToolboxST diagnostic routines.
• Relay contact resistance measurement: each relay output is cycled 50 times and contact resistance verified below 100 mΩ per IEC 61810 criteria.
• Insulation resistance test: 500 VDC applied between relay contact circuits and logic ground; minimum 100 MΩ acceptance threshold.
• IONET communication verification: board is confirmed to enumerate correctly on the ARCNET/IONET bus and respond to controller polling without error flags.
• Burn-in: 48-hour powered soak at 50°C ambient to screen for infant-mortality failures in electrolytic capacitors and relay coil drivers.

Test records are retained per board serial number and are available to customers upon request.