GE IS200 Series Modules: IS200TRLYH1BGG Relay Terminal Module

Technical Dossier

Product Details And Specifications

GE IS200 Series Technical Notes

The GE IS200 series represents the core I/O, control, and communication module family deployed within GE's Mark VI, Mark VIe, and EX2100 turbine and excitation control platforms. These systems are installed across the global heavy industrial base — including combined-cycle power plants, nuclear auxiliary systems, petrochemical refineries, LNG terminals, and offshore platforms. The IS200 series is the backbone of GE's distributed control architecture, providing deterministic real-time control with redundant backplane communication. Installed base figures span tens of thousands of units across North America, Europe, the Middle East, and Asia-Pacific, making long-term spare parts availability a critical operational concern for plant maintenance engineers and reliability teams.

The Evolution of IS200 Architecture

The IS200 module family was introduced alongside the Mark VI turbine control system in the mid-1990s as GE's successor to the Mark V platform. The original Mark VI architecture used VME-based backplane communication with dedicated I/O terminal boards connected via ribbon cable to the VCMI (VME Communication Module Interface). Early IS200 modules — including the TSVOH, TREGH, and TRLYH families — were designed for direct terminal board mounting in the and

racks.

With the introduction of the Mark VIe platform (circa 2005–2010), GE transitioned to an Ethernet-based I/O network (IONet) using the IS200 ENET series, while retaining backward-compatible terminal board form factors for many I/O types. This created a dual-generation compatibility challenge: IS200 terminal boards from the Mark VI era are physically interchangeable with Mark VIe systems in many configurations, but firmware and SCOM (Serial Communication) addressing must be verified against the specific platform revision.

By 2015, GE had begun transitioning select IS200 functions into the Mark VIeS (Safety) and Mark VIeD (Distributed) variants, introducing IS200-series modules with enhanced SIL-2 certification for safety-instrumented applications. The IS200TRLYH1BGG — a relay output terminal board — belongs to the mature Mark VI generation and remains in active demand as a replacement part for legacy installations that are not scheduled for full platform migration.

IS200 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked IS200 series modules. Each entry reflects a distinct functional role within the Mark VI / Mark VIe control architecture.

Relay & Digital Output Terminal Boards

• IS200TRLYH1BGG: Relay output terminal board; 16-channel electromechanical relay outputs for discrete control signals in turbine protection circuits.
• IS200TRLYH1B: Relay output terminal board, base revision; functionally equivalent to H1BGG, earlier hardware suffix.
• IS200TSVOH1B: Servo output terminal board; provides analog servo drive outputs for valve positioning in turbine fuel and steam control loops.
• IS200TREGH1B: Relay and emergency trip terminal board; integrates relay outputs with hardwired emergency trip logic for turbine overspeed protection.

Analog Input Terminal Boards

• IS200TBCIH1C: Thermocouple input terminal board; 12-channel cold-junction compensated thermocouple inputs for exhaust temperature monitoring.
• IS200TBAIH1C: Analog input terminal board; 12-channel 4–20 mA / 0–10 V universal analog inputs for process variable acquisition.
• IS200TPROH1B: Proximity probe input terminal board; conditions Bently Nevada-compatible eddy-current probe signals for shaft vibration and position monitoring.
• IS200TTURH1B: Turbine speed input terminal board; processes magnetic pickup and proximity probe signals for overspeed detection and speed governing.

Digital Input Terminal Boards

• IS200TBCIH1B: Contact input terminal board; 24-channel dry-contact discrete inputs for limit switches, pressure switches, and permissive logic.
• IS200TBTCH1C: Thermocouple and contact input combination board; mixed I/O for compact panel configurations.

CPU & Controller Modules

• IS200VCMIH2C: VME Communication Module Interface; primary CPU carrier for Mark VI, manages I/O network polling and control execution.
• IS200VCRCH1B: VME Controller Redundancy Card; enables TMR (Triple Modular Redundancy) voting logic across three VCMI controllers.
• IS200ECTBH1A: Ethernet Communication Terminal Board; IONet interface for Mark VIe distributed I/O expansion.

Power Supply Modules

• IS200EPSMH1A: Power supply module; provides regulated 28 VDC backplane power for IS200 I/O racks.
• IS200EPSMH2A: Enhanced power supply module; higher current capacity variant for fully populated I/O racks with dense relay output loading.

Communication & Network Adapters

• IS200ENEGH1A: Ethernet gateway module; bridges Mark VI serial I/O network to plant-level Ethernet for historian and HMI connectivity.
• IS200STCIH1B: Serial communication interface board; RS-485 / RS-232 interface for legacy device integration and Modbus RTU communication.

Quality Control for the IS200 Range

IS200 terminal boards present specific test challenges due to their mixed-signal backplane architecture and relay output circuits. DriveKNMS applies the following verification protocol to all IS200 units prior to shipment:

• Backplane connector inspection: All DIN-rail and VME backplane connectors are inspected under magnification for bent pins, oxidation, and mechanical damage. Connector resistance is measured at each pin position.
• Relay output functional test: For relay terminal boards including the IS200TRLYH1BGG, each relay channel is individually energized and de-energized under rated coil voltage. Contact resistance is measured in both NO and NC states. Minimum acceptable contact resistance: <100 mΩ.
• Analog signal path verification: Analog input boards are tested with calibrated signal sources across the full input range (0–20 mA, 0–10 V, thermocouple mV ranges). Linearity error must be within ±0.1% of full scale.
• Isolation test: Channel-to-channel and channel-to-chassis isolation is verified at 500 VDC using a calibrated insulation resistance tester. Minimum acceptable isolation: 100 MΩ.
• Firmware revision verification: Where applicable, EPROM or flash firmware revision is documented and cross-referenced against GE's IS200 compatibility matrix for the target Mark VI / Mark VIe platform version.
• Burn-in: Units are powered and cycled for a minimum of 24 hours in a temperature-controlled environment prior to final inspection and packaging.