Function: Digital I/O for the Mark V Control Core

The TCDA card handles contact-input and relay-output duty on a GE Speedtronic Mark V panel, and this listing, DS200TCDAH1BHE, is an H1-group example, offered here as new-surplus open-box stock. On the input side it brings field contacts (limit switches, permissives, status points) into the control logic; on the output side it drives relays that operate contactors, solenoids, and annunciator circuits. Software configuration – not the card's physical layout – decides what each terminal does.

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

About This Open-Box Unit

Open-box in our listings means new-surplus, factory-sourced material that has been taken out of its original retail packaging – typically for inspection or inventory handling – but never installed in service. It carries the same 1-year warranty as our other new-surplus stock. If cosmetic condition matters for your stores program, ask for photos when you request a quote.

Diagnose Before You Order a Replacement

Whether this card is going straight into a panel or onto a spares shelf, it's worth knowing what actually causes TCDA-type alarms before assuming the card itself is the problem. Documented Mark V field cases point to these non-card causes for continuous I/O state cycling or repeated card-lost diagnostics:

• IONET termination resistors reversed between the TCDA and a TCEA card. Termination belongs IN at the TCDA and OUT on every TCEA in the loop.
• A weak or noisy TCPS power supply feeding the core, rather than the TCDA itself.
• Transients on the control power bus, from a battery charger or from de-energizing unsuppressed DC coils nearby.
• A firmware/PROM revision issue – GE has resolved some IONET communication faults this way rather than through hardware replacement.
• Loose seating or a corroded connector pin on the card or its cable.

Also separate the TCDA from its relay partner, TCRA: TCRA's electromechanical relays wear with switching cycles, while the TCDA's logic doesn't share that failure mode, so a relay output that won't energize is more often a TCRA problem. There's no fixed service life for a TCDA card – many run eight-plus years without issue, with cabinet heat, humidity, dust, and voltage transients being the more common real drivers of failure, which is exactly why many sites keep a tested spare like this one on hand rather than sourcing cold after a trip.

What This Part Number Tells You

DS200 is the Mark V-era series prefix, TCDA is the Digital I/O acronym, H1 is the product grouping, and BHE is this unit's functional and artwork revision combination. H1 and G1 TCDA cards are different hardware groupings under the same acronym, so confirm which one your system requires rather than assuming they're interchangeable, and always match the full suffix when ordering.

Related Boards and the Move to Mark VI

TCDA is typically referenced alongside TCRA, TCQA, TCQE, TCEA, STCA, and UCPB. For a longer-term platform view, GE's Mark VI system replaced the DS200 series with IS200-series boards and a different I/O architecture – see our Mark V vs Mark VI: DS200 to IS200 guide. For GE's Speedtronic part-numbering logic, see the GE Speedtronic Part Number Decoder, and for where TCDA sits among other DS200 boards, see GE Mark V DS200 Boards Explained.

What to Send for a Quote

• Full part number and suffix, e.g., DS200TCDAH1BHE
• A label photo, if you have one
• Turbine model and panel configuration (Simplex or TMR)
• Quantity
• Urgency – stocking spare or unit-down replacement

Request a Quote

This DS200TCDAH1BHE is offered new-surplus, open-box, factory-packaged material with a 1-year warranty (see below). Pricing isn't published online since Mark V quotes depend on exact revision and current stock – submit a Request a Quote and expect a response 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 DS200TCDAH1B DS200TCDAH1BHE Digital I/O Board Mark V OPEN BOX
Condition	newSurplusNoBox Factory Packaged. With 1 Year Warranty.