IS215UCVDH5A Process Control Module (H5AP Build)

Catalogued in its IS215UCVDH5AP form, this board is a General Electric Mark VI Speedtronic process control module — a UCVD-generation main controller in the UCVx family. It runs turbine application code from a slot in the Mark VI control module's VME rack and exchanges data with the turbine I/O over the VME backplane. Note the trailing revision: this is the H5AP variant of the H5A build, which matters when you are matching a spare to an installed controller.

QNX, the VME bus, and the control system database

The UCVD executes its control logic as analog and discrete blocks under the QNX real-time operating system, a characteristic confirmed by more than one independent industry reference. It does not connect to the I/O network on its own; process data moves to and from the control system database (CSDB) through the VCMI communication board over the VME bus, with clock synchronization to the VCMI held to within roughly ±100 microseconds. On the faceplate you will find a UDH Ethernet port for the operator/HMI network, serial COM ports (COM1 for setup and diagnostics), and two banks of status LEDs. We do not quote a specific processor clock or memory size for the UCVD, because those varied across the controller's production; treat the board label as the definitive spec.

Diagnose First: The Symptoms That Mimic a Bad UCVD

The controller is easy to blame and expensive to replace on a guess. Before ordering, separate the board from its dependencies:

• Decode the runtime LEDs. The second LED bank reports error codes from download, configuration or startup faults — frequently the actual problem is written right there.
• Clear the VCMI and IONet. A controller isolated from its I/O by a VCMI or network fault mimics a dead processor almost perfectly.
• Verify power and seating. A sagging rack supply or a card not fully home in the VME backplane creates intermittent faults that feel like hardware death.
• Check the firmware and application. A ControlST/firmware version mismatch or a failed download is a software issue; new hardware will not fix it.
• Talk to it on COM1. Successful setup/diagnostic communication is good evidence the controller is alive.

When power, VCMI, network and configuration are all cleared, the H5AP is a sound replacement.

H5AP and why the trailing revision matters

The number reads as IS215 (Mark VI assembly family and GE lineage), UCVD (D-generation VME controller) and H5A with the extended revision H5AP. The dash-number identifies the controller's build and faceplate/I/O configuration; the trailing letter (here, P) tracks the revision, and it can matter for firmware and compatibility. An H5AP is not automatically interchangeable with an H5AN or with an H1A/H7A, so match the complete string — send us a label photo if you are unsure. The GE Speedtronic Part Number Decoder breaks down every field.

Where UCVD fits among GE's Mark VI controllers

GE produced the Mark VI main controller across the UCVB, UCVD, UCVE and UCVG generations, with the UCVD and the popular UCVE as close siblings. A rack designed for one generation expects a matching controller and firmware. Browse the controllers, VCMI boards and companions in the GE Mark VI IS200 Boards collection, or the wider GE Speedtronic Turbine Control Boards catalog; the Mark V vs Mark VI: DS200 to IS200 guide sets the platform in context.

Your quote request, streamlined

• Full part number and suffix (IS215UCVDH5A / H5AP) exactly as printed on the label.
• 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 lead-time needs.

Request Your H5AP Quote

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 attach your label photo so we can confirm the exact revision.

General Information about the Product
Part Number	IS215UCVDH5A Mark VI IS215
Description	IS215UCVDH5A By GE IS215UCVDH5AP Process Control Module
Condition	used Cleaned and Tested. With 1 Year Warranty.