GE IS200T Series Modules — IS200TBAIS1C Analog I/O Terminal Board

Technical Dossier

Product Details And Specifications

GE IS200T Series: Comprehensive Module Range and Technical Overview

The GE IS200T series constitutes the terminal board layer of GE's Mark VI and EX2100 turbine control systems — platforms deployed across heavy industrial sectors including petrochemical refineries, nuclear power stations, combined-cycle gas turbine plants, and offshore oil & gas facilities. These terminal boards serve as the physical interface between field instrumentation (thermocouples, RTDs, pressure transmitters, servo actuators) and the Mark VI I/O processor modules. The IS200T series is not a standalone controller family; it operates in conjunction with IS200S-series I/O packs and IS215-series VME processor boards, forming a layered architecture that defines GE's Speedtronic control philosophy. Global installed base estimates place Mark VI systems in operation at thousands of turbine units worldwide, making IS200T terminal boards among the most frequently sourced industrial spare parts in the power generation sector.

The Evolution of IS200T Architecture

The IS200T terminal board series was introduced alongside the Mark VI control system in the mid-1990s as GE's successor to the Mark V (IS200-series predecessor boards used a different connector and backplane standard). The Mark VI architecture introduced a distributed I/O topology using JR45 ribbon connectors and a dedicated I/O LAN (IONet), replacing the earlier parallel backplane bus of Mark V. IS200T boards are passive or semi-passive: they carry no onboard firmware but route analog and digital signals through precision resistor networks, isolation transformers, and terminal blocks to the mating I/O pack.

With the introduction of the Mark VIe platform (circa 2005–2010), GE extended compatibility: many IS200T terminal boards remain electrically compatible with Mark VIe I/O packs via adapter harnesses, though the Mark VIe introduced IS420T-series boards as the native terminal layer. The IS200T series entered its mature/end-of-active-production phase approximately 2015–2018. GE (now part of GE Vernova / Baker Hughes control systems portfolio) no longer manufactures IS200T boards as new production items; procurement is exclusively through authorized distributors, surplus channels, and specialist MRO suppliers. Long-term maintenance support for IS200T-equipped plants is a defined operational requirement for facilities with 10–20 year remaining turbine service life.

IS200T Full Catalog & Functionalities (SKU List)

Analog I/O Terminal Boards

• IS200TBAIS1C: Analog input terminal board; 16-ch thermocouple/mV input interface for Mark VI I/O pack
• IS200TBAIS1A: Analog input terminal board, revision A; earlier hardware revision of TBAIS1C
• IS200TBAIS1B: Analog input terminal board, revision B; intermediate hardware revision
• IS200TBAOS1A: Analog output terminal board; interfaces 4–20 mA current loop outputs to field actuators
• IS200TBAOS1B: Analog output terminal board, revision B; updated output drive circuitry
• IS200TBCAS1A: Combined analog I/O terminal board; mixed input/output channel configuration

Digital I/O Terminal Boards

• IS200TBDIS1A: Digital input terminal board; 24 VDC discrete input interface, 32-channel capacity
• IS200TBDOS1A: Digital output terminal board; relay-driven discrete output interface for solenoids/contactors
• IS200TBDOS1B: Digital output terminal board, revision B; enhanced relay contact rating
• IS200TBCIS1A: Contact input terminal board; dry-contact and wet-contact discrete input interface
• IS200TBCIS1B: Contact input terminal board, revision B; updated input filter network

Speed/Pulse & Servo Terminal Boards

• IS200TSVOH1A: Servo output terminal board; interfaces electrohydraulic servo valve (EHSV) control signals
• IS200TSVOH1B: Servo output terminal board, revision B; updated current drive stage
• IS200TBCCH1A: Speed/pulse input terminal board; magnetic pickup (MPU) and proximity probe interface
• IS200TBCCH1B: Speed/pulse input terminal board, revision B; improved EMI filtering on MPU inputs

Communication & Power Interface Boards

• IS200TPROH1A: Power supply interface terminal board; routes 28 VDC and 5 VDC rails to I/O pack connectors
• IS200TPROH1B: Power supply interface terminal board, revision B; updated fusing and protection circuitry
• IS200TBCAS1B: Combined analog terminal board, revision B; field wiring terminal block upgrade

Sourcing Hard-to-Find & Obsolete IS200T Parts

DriveKNMS maintains a dedicated inventory program for IS200T series terminal boards, targeting the specific procurement challenges faced by power plant maintenance teams operating Mark VI-equipped turbines past the OEM active support window. Key sourcing capabilities include: verified surplus stock of low-volume IS200T variants (including early A-revision boards no longer available through GE distribution); cross-reference matching between IS200T part numbers and their IS420T Mark VIe equivalents where electrical compatibility exists; and direct procurement support for emergency outage scenarios requiring same-week shipment. All IS200T boards sourced by DriveKNMS are subject to visual inspection, connector integrity verification, and where applicable, functional bench testing prior to dispatch. Requests for specific revision levels (A, B, C) are accommodated where stock permits.

Quality Control for the IS200T Range

IS200T terminal boards present specific inspection challenges due to their passive signal-routing architecture and the precision nature of their analog input networks. DriveKNMS applies the following test protocol to IS200T boards: (1) Visual inspection of all JR45 ribbon cable connectors for bent pins, corrosion, and mechanical damage — the primary failure mode for terminal boards in service. (2) Continuity verification across all signal paths from field terminal blocks to I/O pack connectors using calibrated resistance measurement. (3) Isolation resistance testing between signal channels and chassis ground, with minimum acceptance threshold of 100 MΩ at 500 VDC for analog input boards including IS200TBAIS1C. (4) Thermocouple input boards (TBAIS series) are verified for correct cold-junction compensation resistor values using precision LCR measurement. (5) Boards with visible PCB contamination, flux residue, or evidence of field repair are quarantined and not offered for resale. All test records are retained and available upon request with shipment documentation.

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