What DS200TCDAH1BHD Is and Where It Mounts

Every Speedtronic Mark V panel that reads contact inputs and drives relay outputs uses a TCDA card to do it, and DS200TCDAH1BHD is an H1-group version of that Digital I/O board. It carries field signals – limit switches, permissives, status contacts – into the control logic, and carries relay-driven signals back out to contactors, solenoids, and annunciators. The specific function of each terminal is set by the turbine's software configuration rather than by the card's physical wiring.

You'll find this card in one of the Mark V's control cores: <R>, <S>, or <T> on a TMR panel, or the single core on a Simplex panel. TCDA is also documented as part of the card set in the <C> communication core on many installations. In the rack, it partners with a relay-output board (usually called TCRA) and with I/O cards such as TCQA, TCQE, and TCEA on the panel's IONET.

Confirm the Fault Before You Order

Plenty of TCDA replacements get ordered for faults that aren't actually the TCDA. Documented Mark V troubleshooting shows these look-alike causes for typical TCDA symptoms – continuous I/O status cycling, repeat "card lost" diagnostics:

• IONET termination set backwards. Termination belongs IN at the TCDA and OUT on every TCEA card in the loop – get one TCEA wrong and a healthy TCDA will show the same fault.
• The TCPS power supply to the core, not the TCDA – check the rails reaching the card first.
• Battery-bus noise or transients, including spikes from a charger or from de-energizing unsuppressed DC coils near the panel.
• A PROM/firmware gap. Some IONET communication faults have been resolved by GE with a firmware update, not a card change.
• A loose card or a corroded connector pin on the board or its ribbon cable.

Separate the TCDA from its relay partner, TCRA, in your thinking: TCRA's electromechanical relays wear out from switching cycles, while the TCDA's logic doesn't share that failure path. A relay output that won't pick up is usually a TCRA issue first. There's no fixed service life for a TCDA – many run eight-plus years without a hiccup, and published experience with Mark V cards puts mean time between failures in the low hundreds of thousands of hours, with cabinet heat, humidity, dust, and voltage transients responsible for most real failures rather than age by itself.

Decoding DS200TCDAH1BHD

DS200 is the Mark V-era series prefix, TCDA is the Digital I/O acronym, H1 is the product grouping for this card, and BHD is the specific revision combination of this unit. H1 and G1 TCDA cards are distinct hardware groupings rather than interchangeable revisions of one board – check your Mark V documentation before substituting one for the other. Order against the complete part number, DS200TCDAH1BHD, and confirm it against the physical label on the card you're replacing.

Related Boards and Longer-Term Options

TCDA typically appears in the same discussions as TCRA, TCQA, TCQE, TCEA, STCA, and UCPB. For sites considering a platform migration, GE's Mark VI system uses IS200-series boards instead of the DS200 series, with a different I/O architecture; see our Mark V vs Mark VI: DS200 to IS200 guide for the general picture. For an explanation of GE's Speedtronic part numbering, see the GE Speedtronic Part Number Decoder, and for how TCDA compares with the rest of the DS200 family, see GE Mark V DS200 Boards Explained.

What We Need From You to Quote

• Complete part number and suffix, e.g., DS200TCDAH1BHD
• A photo of the label if available
• Turbine model and panel type (Simplex or TMR)
• Quantity
• Urgency – planned work or unplanned downtime

Request a Quote

This DS200TCDAH1BHD is offered used, clean and tested, backed by a 1-year warranty (details below). Pricing is never published online for Mark V boards since it depends on exact revision match and current stock – submit a Request a Quote and hear back within 24 hours. We ship worldwide DDP, accept purchase orders, and support both scheduled maintenance and turbine-down emergencies.

General Information about the Product
Part Number	DS200TCDAH1B Mark V DS200
Description	GE DS200TCDAH1B DS200TCDAH1BHD Digital I/O Board Mark V
Condition	used Clean and Tested. With 1 Year Warranty.