IS215UCVEH2A: The Standard Mark VI Main Controller

The IS215UCVEH2A is the standard main controller of the GE Speedtronic Mark VI turbine control system — the single-slot VME processor card that runs the turbine application and drives the rack's I/O. This unit is offered as new-surplus, factory-packaged stock at the H2AE revision (listed as an open-box item), which makes it well suited to a critical spare or a planned controller replacement.

What Runs on the Card

The UCVE — the "E" generation of GE's UCVx controller line — executes the control application under the QNX operating system on a 300 MHz Intel Celeron processor with 32 MB of DRAM, figures corroborated across independent vendor teardowns. A single 10BaseT/100BaseTX Ethernet port (RJ-45) links the controller to the Unit Data Highway (UDH). The board draws +5 V dc at roughly 6 A typical and 8 A maximum, which matters when you are diagnosing power-related faults. Each time the rack powers up, the controller validates its toolbox configuration against the installed hardware.

Simplex and TMR Operation

The Mark VI runs in both simplex and triple-modular-redundant (TMR) architectures. In a TMR system three controllers occupy the <R>, <S> and <T> cores; their inputs are voted, computed outputs are voted by the output hardware, and internal state values are exchanged among the three. A key consequence for troubleshooting: with one core down, the turbine keeps running on the remaining two, so a single UCVE fault does not always announce itself as a trip.

Diagnose the Fault Before Replacing the Controller

A Mark VI diagnostic alarm or a core that will not boot looks like a controller failure, but the UCVE is frequently the victim rather than the culprit. Check these first:

• Firmware and configuration. Because the controller validates its configuration against the hardware at power-up, a bad ControlST download, a mismatched application, or corrupted boot flash can fault the board. Reload the firmware and application before condemning it.
• The VCMI and the backplane. The UCVE reaches the I/O only through the VCMI communication board over the VME backplane, and it synchronizes to the VCMI's clock. A VCMI fault, a backplane seating problem, or an IONet issue can look exactly like a dead controller.
• Rack power. A sagging +5 V rail resets a processor that draws up to 8 A. Verify the VME rack power supply.
• An I/O board reporting upstream. A single failed I/O pack or board can raise diagnostics that appear to originate at the controller.
• Which core? In TMR, isolate whether <R>, <S> or <T> is affected — and whether the fault is the UCVE or its rack, VCMI or power — before swapping.

Reading the UCVE Part Number

IS215 identifies the Mark VI special assembly, UCVE is the controller type and generation, H2A is the hardware variant, and the trailing letter (the "E" in H2AE) is the revision. The generation letter matters: UCVE is one of several UCVx controller generations (UCVB, UCVD, UCVE and UCVG), and they are not freely interchangeable. Match the full part number, including suffix, to the board you are replacing; the GE Speedtronic Part Number Decoder explains every field.

VCMI, the Backplane and Related Boards

The controller's closest companion is the VCMI communication board; together they sit in the Mark VI VME rack. For context on how the platform evolved, see Mark V vs Mark VI: DS200 to IS200, and browse related cards in our GE Mark VI IS200 Boards collection.

Request a Quote for This IS215UCVEH2A

For a precise quote, send the full part number and suffix (IS215UCVEH2A / H2AE), the revision, a photo of the board label, the turbine model and Mark VI generation, whether the system is simplex or TMR, the ControlST or firmware version if known, the quantity, and your urgency.

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