GE Mark VI IS200TVIBH2BBB (IS200TVIBH2B) Vibration Termination Board

Technical Dossier

Product Details And Specifications

GE Mark VI Series Technical Notes

The GE Mark VI Turbine Control System is one of the most widely deployed distributed control platforms in global heavy industry. Installed across gas turbine power plants, combined-cycle facilities, petrochemical refineries, nuclear auxiliary systems, and offshore platforms, the Mark VI architecture has served as the backbone of turbine protection and sequencing logic since its commercial introduction in the mid-1990s. Its modular I/O design, redundant backplane communication, and deterministic real-time processing made it the successor to the Mark V and the predecessor to the Mark VIe. Tens of thousands of units remain in active service worldwide, making long-term spare parts availability a critical operational concern for plant engineers and maintenance managers.

The Evolution of Mark VI Architecture

The Mark VI was introduced by GE Energy (now GE Vernova) as a VME-bus-based control platform designed for high-reliability turbine applications. Its architecture centers on the VCMI (VME Communication Module Interface) backplane, which interconnects processor boards, I/O termination boards, and power supply modules within a single rack. Early revisions (Rev A/B) established the core I/O mapping and redundancy model. Subsequent hardware revisions introduced improved ASIC-based signal conditioning, expanded vibration monitoring channels, and enhanced EMI shielding on termination boards.

The Mark VI operates on a deterministic IONet (I/O Network) protocol, distinguishing it from later Ethernet-based architectures used in the Mark VIe. This makes Mark VI hardware non-interchangeable with Mark VIe modules at the board level, a critical compatibility constraint for maintenance planning. As the Mark VI has entered its mature/end-of-life phase, GE has formally discontinued new production of most module variants. Plants operating Mark VI systems must now rely on certified aftermarket suppliers and refurbished inventory for corrective and preventive maintenance.

Mark VI Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked modules within the GE Mark VI ecosystem, organized by functional category. Each entry reflects a real hardware variant documented in GE Mark VI technical manuals and field service records.

Vibration & Termination Boards

• IS200TVIBH2BBB (IS200TVIBH2B): Vibration termination board, Rev B, dual-channel proximity probe interface with buffered outputs and trip relay contacts.
• IS200TVIBH1B: Vibration termination board, Rev B single-channel variant, used in simplex turbine protection configurations.
• IS200TVIBH2CAB: Vibration termination board, Rev C, enhanced EMI filtering for high-noise plant environments.

Analog I/O Modules

• IS200AAIAH1A: Analog input module, 16-channel, 4–20 mA, used for process variable acquisition in turbine control loops.
• IS200AAOAH1A: Analog output module, 8-channel, 4–20 mA, drives control valves and actuators.
• IS200ATAIH1A: Thermocouple analog input termination board, supports J/K/T/E type thermocouples for exhaust temperature monitoring.

Digital I/O Modules

• IS200DAIAH1A: Digital input module, 24 VDC, 32-channel, used for discrete status and permissive logic inputs.
• IS200DAOAH1A: Digital output module, relay-type, 16-channel, drives solenoid valves and alarm annunciators.
• IS200EDCFH1A: DC power distribution and fusing board for Mark VI I/O racks.

Processor & Controller Boards

• IS200UCVEH2A: VME-based main controller board, dual-redundant CPU with IONet interface, core processing unit for Mark VI control.
• IS200UCVEH2B: Revised controller board with expanded memory and improved watchdog timer circuit.
• IS200VCRCH1B: VME crate controller, manages backplane arbitration and module health monitoring.

Communication & Network Modules

• IS200ENEGH1A: Ethernet network interface module, provides HMI and historian connectivity via 100BASE-TX.
• IS200IOCIH1A: IONet communication interface card, bridges VME backplane to the plant-wide IONet ring.
• IS200STCIH1A: Serial communication termination board, supports RS-232/RS-485 for legacy device integration.

Power Supply Modules

• IS200EPSMH1A: Mark VI rack power supply module, 28 VDC output, supports redundant power configurations.
• IS200EPSMH2A: Enhanced power supply module with improved thermal management for high-ambient installations.

Sourcing Hard-to-Find & Obsolete Mark VI Parts

GE has formally ended new production of the majority of Mark VI hardware, including the IS200TVIBH2BBB termination board. For plants committed to operating Mark VI systems through extended maintenance cycles, DriveKNMS maintains a dedicated inventory of tested, refurbished, and new-surplus Mark VI modules sourced from decommissioned units, OEM overstock, and certified third-party refurbishers.

Quality Control for the Mark VI Range

All Mark VI modules processed by DriveKNMS undergo a structured inspection and functional test protocol prior to dispatch. For termination boards such as the IS200TVIBH2BBB, the test procedure includes:

• Visual inspection of PCB traces, connector pins, and solder joints under magnification.
• Backplane connector continuity and isolation resistance testing per GE GEH-6421 service manual specifications.
• Functional verification of proximity probe signal conditioning circuits using calibrated signal injection equipment.
• Trip relay contact resistance measurement and actuation cycle testing.
• Buffered output signal integrity verification under simulated load conditions.
• Final burn-in test at elevated temperature to screen for latent component failures.

VME-bus communication modules and IONet interface cards undergo additional protocol-level testing using a dedicated Mark VI rack test bench to verify correct backplane arbitration and data frame integrity.