Description
GE IS230TDBTH6A | 125 VDC TMR Discrete I/O | Mark VIe Terminal Board
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | General Electric |
| Model | IS230TDBTH6A |
| Associated PCB | IS200TDBTH6ABC |
| Functional Acronym | TDBT |
| Product Type | Discrete Input/Output Terminal Board |
| System | GE Mark VIe |
| Architecture | TMR |
| Contact Inputs | 24 group-isolated inputs |
| Nominal Input/Wetting Voltage | 125 VDC |
| Input Voltage Range | 100–145 VDC |
| Input Filter | Approx. 4 ms hardware filter |
| Relay Outputs | 12 Form-C |
| I/O Pack | PDIO |
| I/O Pack Connections | Three PDIO interface connections |
| Mounting | DIN rail or flat panel |
| Terminal Blocks | TB1 / TB2, pluggable |
| Board Size | Approx. 17.8 × 33.0 cm |
| Operating Temperature | Approx. -30°C to +65°C |
| Contact Material | Silver cadmium oxide |
| Surface Technology | Surface-mount construction |
The represents the DIN-rail/special-assembly implementation of the TDBT design. The H6 version is the 125 VDC variant: its 24 group-isolated contact inputs accept a nominal 125 VDC wetting voltage, with a published operating range of approximately 100–145 VDC. The terminal board also provides 12 Form-C relay outputs.
Product Introduction
The is a TDBT discrete input/output terminal board used in GE Mark VIe turbine-control systems. It provides the field-side interface for 24 isolated contact inputs and 12 Form-C relay outputs, with the H6 configuration specifically intended for 125 VDC contact circuits. The board is designed for DIN-rail or flat-panel installation and works with the appropriate PDIO I/O pack architecture.
The is not a standalone PLC processor or conventional rack I/O card. Its job is to terminate, condition, and route field discrete signals to the active PDIO I/O pack. In a TMR Mark VIe installation, multiple PDIO communication paths can be used to support the controller architecture. This distinction matters during procurement because replacing the terminal board does not replace the associated I/O pack or controller-side hardware.
IS230TDBTH6A
Application Scenarios & Field Pitfalls — The Engineer’s Perspective
Engineering Pain Point
A 125 VDC discrete-input fault on a Mark VIe turbine can be caused by the field circuit, wetting-voltage supply, terminal board, PDIO pack, wiring, or controller communication path. The should therefore be tested as part of the complete I/O chain rather than being condemned solely because an input status is missing.
Typical Applications
1. Turbine auxiliary contact monitoring
The 24 isolated contact inputs can monitor turbine auxiliary equipment, permissives, interlocks, breaker status, valve status, and other discrete field conditions.
2. High-voltage DC contact circuits
The H6 configuration is specifically associated with 125 VDC nominal contact-input circuits, making it unsuitable for direct substitution with the 24 VDC or 48 VDC TDBT variants.
3. Relay-based control
The 12 Form-C relay outputs provide changeover contacts for external control circuits. Actual relay loading must be checked against the voltage-specific contact ratings.
4. TMR turbine-control architecture
The TDBT design can be used with PDIO I/O packs in redundant Mark VIe configurations. The number and arrangement of active I/O packs must match the installed control architecture.
Technical Pitfalls
1. Verify H6 voltage before replacement.
TDBT boards are available in different voltage variants. The H6 version is the 125 VDC configuration, while TDBTH2A and TDBTH4A represent different nominal wetting-voltage classes. Substituting by physical appearance alone is unsafe.
2. Do not confuse with the electronic PCB number.
The IS230 designation identifies the special DIN-rail assembly. The underlying PCB is commonly identified as IS200TDBTH6ABC. Procurement records should preserve both identifiers when possible.
3. The terminal board is not the PDIO pack.
The PDIO is the active I/O electronics that communicates with the controller. The TDBT provides the field interface. Replacing a TDBT board will not correct a failed PDIO pack.
4. Check the external wetting-voltage supply.
The H6 input circuits depend on the correct external DC source. A missing or unstable 125 VDC supply can make multiple inputs appear faulty simultaneously.
5. Check the relay section separately.
The 12 Form-C relay outputs are a different failure path from the contact-input circuits. Inspect relay contacts, field wiring, external power, and any installed WROB/WROBH option hardware when troubleshooting output problems.
6. Inspect the PDIO connections.
The TDBT assembly uses dedicated I/O-pack connections. Loose connectors, damaged pins, contamination, or incorrect mating hardware can produce intermittent I/O faults that resemble a defective board.
7. Verify the exact system architecture.
Some listings describe this hardware simply as Mark VI, while others identify it as Mark VIe. The more useful procurement description is the TDBT special assembly associated with the IS200TDBTH6ABC design and PDIO architecture. Do not substitute another similarly numbered Mark VI board without checking the actual cabinet configuration.
Related Products
- GE IS200TDBTH6ABC — underlying TDBT PCB associated with the assembly.
- GE IS230TDBTH2A — 24 VDC TDBT variant.
- GE IS230TDBTH4A — 48 VDC TDBT variant.
- GE IS230TDBSH6A — related TDBS 125 VDC discrete I/O terminal-board configuration.
- GE IS200WROB — relay option board used with compatible TDBT/TDBS configurations.
- GE IS200TRLYH1B — relay-output terminal-board family with related functionality.
- GE PDIO I/O Pack — active I/O electronics used with the TDBT terminal-board architecture.
- GE IS230TBCIH4C — related DIN-rail contact-input terminal assembly.
- GE IS230TBCIH5C — related 125 VDC contact-input configuration.
- GE IS230TBAI1CG01 — T-type analog terminal-board assembly for a different I/O function.
Procurement Note
When sourcing , match the H6 configuration, 125 VDC input class, complete assembly number, associated IS200 PCB number, PDIO interface, and TMR cabinet architecture.
For surplus or refurbished inventory, inspect the DIN-rail carrier, terminal blocks, PDIO connectors, relay contacts, MOV protection components, PCB coating, and evidence of overheating or field overvoltage. The presence of the correct label is not sufficient if the assembly has been modified or combined with an incompatible option board.
A particularly important distinction is vs. IS230TDBTH2A/IS230TDBTH4A. These boards may look similar mechanically, but their input wetting-voltage classes differ. The H6 designation should be treated as a functional requirement, not merely a catalog suffix.
Engineering classification: GE — Mark VIe TDBT 125 VDC TMR discrete input/output terminal board, supporting 24 group-isolated contact inputs and 12 Form-C relay outputs with PDIO I/O packs.
