IS215UCVDH5A: A Mark VI UCVx Main Controller

The IS215UCVDH5A is a General Electric Speedtronic Mark VI main controller from the UCVx family — the "D" generation, catalogued here in its H5AN build as a process control module. It is one of GE's VME-based turbine controllers: the card seats in the control module's VME rack and runs the turbine application code that governs the machine. The UCVD is one of five major versions of this controller, and it is the direct sibling of the more commonly seen UCVE main controller.

VME rack residence and the VCMI link

The UCVD mounts in the Mark VI VME rack and talks to the turbine I/O across the VME backplane bus. It does not reach the I/O network directly; instead it exchanges data with the control system database (CSDB) through the VCMI communication interface over the VME bus, and it synchronizes to the VCMI to within about ±100 microseconds. In a triple-modular-redundant system the <R>, <S> and <T> cores each carry their own controller and VCMI. The board runs the QNX real-time operating system — a point confirmed across independent references — and executes control logic using analog and discrete blocks. One honest note on specifications: the processor and memory fitted to the UCVD differ across its builds, so we do not publish a single clock speed or memory figure; match the full part number to your board.

Diagnose Before You Buy: Controller or Its Surroundings?

A halted turbine controller is alarming, but the root cause is frequently outside the board. Work through these before ordering a replacement:

• Read both LED banks. The UCVD carries two sets of status LEDs — one for controller and communication status, one that displays runtime error codes from download, configuration or startup problems. Note the codes before pulling anything.
• Suspect the VCMI and IONet first. Because the controller depends on the VCMI to reach the I/O, a VCMI or IONet fault can look exactly like a failed controller.
• Check power supplies and the backplane. A weak rack supply or a backplane/seating problem produces intermittent, controller-like symptoms.
• Separate firmware and configuration from hardware. A failed application download or a ControlST/firmware mismatch is a software fix, not a new board.
• Confirm the COM path. COM1 is for setup and diagnostics; use it to reach the controller before concluding it is dead.

Only when the VCMI, network, power and configuration are proven good should the UCVD itself be replaced.

The H5A / H5AN suffix and what it fixes

Read the number in blocks: IS215 is the Mark VI assembly family and GE lineage, UCVD is the D-generation VME controller function, and H5A (extended as H5AN) is the specific hardware build and revision. Within the UCVD line the dash-number reflects the faceplate and I/O configuration, and the trailing letters track revision. Match the full string — an H5A is not the same as an H1A or H7A. Our GE Speedtronic Part Number Decoder walks through every field.

UCVD, UCVE, and the rest of the UCVx family

The Mark VI main controller was produced across generations — UCVB, UCVD, UCVE and UCVG. The UCVD and the widely used UCVE are close siblings, so if your system was built or upgraded around one of them, confirm which generation your rack expects. Related boards, including the VCMI interface, are in the GE Mark VI IS200 Boards collection and the broader GE Speedtronic Turbine Control Boards range; for platform history, see Mark V vs Mark VI: DS200 to IS200.

What to include in your quote request

• Full part number and suffix (IS215UCVDH5A / H5AN) exactly as labeled.
• A photo of the controller label and revision.
• Turbine model, Mark VI generation, and simplex or TMR (<R>/<S>/<T>) architecture.
• ControlST/ToolboxST firmware version if known, quantity, and urgency.

Request a Quote on This UCVD

This IS215UCVDH5A is offered as cleaned-and-tested used stock with a one-year warranty. Send your details and we will respond with a quote within 24 hours. We ship worldwide DDP and accept purchase orders from qualified organizations. Use Request a Quote and include your label photo so we can confirm the exact UCVD build.

General Information about the Product
Part Number	IS215UCVDH5A Mark VI IS215
Description	GE General Electric IS215UCVDH5A IS215UCVDH5AN Process Control Module Mark VI
Condition	used Cleaned and Tested. With 1 Year Warranty.