DS200TCDAH1BHD: The Mark V's Digital I/O Board

Among the cards in a Speedtronic Mark V control panel, the TCDA is the one responsible for contact inputs and relay outputs, and DS200TCDAH1BHD is an H1-group version. It's also one of the more frequently replaced TCDA part numbers we see, simply because H1BHD panels are common in the installed base. The board reads field contacts – limit switches, permissives, status points – into the control logic, and drives relay outputs to contactors, solenoids, and annunciator circuits. Which terminal does which job is set by software configuration, not by the card's physical layout.

The TCDA is installed in one of the Mark V's control processor cores: <R>, <S>, or <T> in a TMR panel, or the single core in a Simplex panel. It's also documented as part of the card set in the <C> communication core on many installations, working with a companion relay board (TCRA) and I/O cards such as TCQA, TCQE, and TCEA over the IONET.

Before You Order, Rule Out These Look-Alike Faults

Because this exact revision turns over often, it's worth being precise about what actually causes a TCDA-type alarm before assuming the card is bad. Documented Mark V field cases attribute classic TCDA symptoms – continuous I/O status cycling, repeated card-lost diagnostics after a trip – to causes including:

• IONET termination resistors reversed between the TCDA (should be IN) and a TCEA card (should be OUT) somewhere in the loop.
• The TCPS power supply feeding the core, rather than the TCDA card itself – check its rails first.
• Ripple or voltage spikes on the DC control bus, from a battery charger or from de-energizing unsuppressed DC coils near the panel.
• An unresolved PROM/firmware revision – GE has fixed certain IONET communication issues with a firmware update rather than a card swap.
• A loose card or a corroded connector pin on the board or its ribbon cable.

Also separate the TCDA from its relay-output partner, TCRA, in your thinking: TCRA's relays are electromechanical and wear out through switching cycles, while the TCDA's solid-state logic doesn't fail that way. A relay output that won't energize points to TCRA more often than to this card. There's no fixed service life for a TCDA – many run eight-plus years without a problem, and general Mark V experience places mean time between failures in the low hundreds of thousands of hours, with cabinet heat, humidity, dust, and voltage transients causing most real-world failures rather than age on its own.

What H1BHD Tells You

DS200 is the Mark V-era series prefix, TCDA is the Digital I/O acronym, H1 is this board's product grouping, and BHD is the specific functional and artwork revision combination. H1 and G1 TCDA cards are distinct hardware groupings sold under the same acronym – they are not automatically interchangeable, so confirm which one your Mark V documentation calls for and match the full suffix, not just the base TCDA number.

Related Boards and Longer-Term Alternatives

TCDA typically comes up alongside TCRA, TCQA, TCQE, TCEA, STCA, and UCPB. For plants weighing a platform change, GE's Mark VI system replaced the DS200 series with IS200-series boards under a different I/O architecture; see our Mark V vs Mark VI: DS200 to IS200 guide. For the mechanics of GE's Speedtronic part numbering, see the GE Speedtronic Part Number Decoder, and for how TCDA fits with the rest of the DS200 lineup, see GE Mark V DS200 Boards Explained.

What to Send With Your Quote Request

• The full part number and suffix, e.g., DS200TCDAH1BHD
• A photo of your existing card's label
• Turbine model and Mark V configuration (Simplex or TMR)
• Quantity needed
• Urgency – stocking spare or unit-down replacement

Request a Quote

This DS200TCDAH1BHD is new-surplus, open-box stock, inspected and tested before dispatch, with a 1-year warranty (see below). Pricing isn't published online since Mark V board quotes depend on exact revision availability – submit a Request a Quote and our team will respond within 24 hours. We ship worldwide DDP, accept purchase orders, and support both spares planning and urgent turbine-down orders.

General Information about the Product
Part Number	DS200TCDAH1B Mark V DS200
Description	GE General Electric DS200TCDAH1B DS200TCDAH1BHD Digital I/O Control PC Board
Condition	newSurplusNoBox New Surplus Open Box. With 1 Year Warranty