Function of the IS215VCMIH1B Bus Master Controller

The IS215VCMIH1BB is a VCMI board — VME Communications Interface — for the GE Speedtronic Mark VI turbine control system. It is the VME bus master for its rack: it manages the board IDs of everything installed in that rack and its terminal boards, moves I/O data to the UCVE processor over the backplane, and provides the rack's only connection to IONet, the network that links it to the VPRO protection boards.

H1 is the single-IONet-port version of the VCMI, running at 10 Mbit/s over a 10Base2 BNC connection, built around a Texas Instruments TMS320C32 digital signal processor with dual-port and flash memory. GE's system manual for this hardware is GEH-6421.

Single-Channel vs Triple-Redundant: Where H1 Fits

The practical difference between VCMI versions is IONet port count. H1 has a single IONet port, which fits simplex Mark VI systems or a single channel of a larger system. H2 adds two more IONet ports so that one board design can serve all three <R>/<S>/<T> channels of a TMR system. If your rack is simplex, or if you're replacing a single channel's card in a system that uses individual VCMIs per channel, H1 is the right family — check your existing board before assuming you need the three-port H2 version.

Troubleshooting Before Replacement

Loss-of-communication alarms involving a VCMI don't always mean the card has failed. Documented field experience points to several other causes worth checking first:

• IONet cable and BNC connector condition — corrosion, looseness, or damaged terminal resistors are common causes of intermittent communication faults.
• VME supply voltages at the card (5V, 15V) and general PDM (power distribution module) health.
• GE TIL-1905, covering VCMI (H1B, H1C, H2B, H2C) and VPRO boards built between May 2006 and February 2009, where oxidation on a socketed IONet transceiver chip has caused intermittent faults that mimic board failure.
• Environmental contributors: RF interference near open panel doors, grounding issues, corrosive atmospheres, and condensation inside the cabinet.

Powering the rack down, removing the card, cleaning the card and its slot, and reseating it has resolved persistent diagnostic alarms in documented cases without any board being replaced at all — worth trying before assuming the card is dead.

Decoding IS215VCMIH1BB

IS215 marks this as a Mark VI-generation assembly, VCMI the function, H1 the single-IONet-port design, and BB the specific revision. Match the revision to your Toolbox configuration; the revision is marked on the card edge visible when the board is installed. Send us a photo of your existing board's label and we'll confirm fit before you order.

Cross-Generation Notes

If your outage also touches VPRO boards, terminal boards, or older Mark V hardware, our GE Speedtronic Part Number Decoder covers any IS200/IS215 part number, and Mark V vs Mark VI: DS200 to IS200 explains how the two generations connect. See the rest of the family in our GE Mark VI IS200 Boards collection.

Information We Need From You

• Full part number and suffix (IS215VCMIH1BB), with revision
• A photo of the label on the board being replaced
• Turbine model and Mark VI configuration (simplex or TMR)
• Quantity and urgency

Request a Quote — Worldwide DDP

This IS215VCMIH1BB is new surplus, factory packaged, cleaned and tested, with a 1-year warranty. We quote worldwide with DDP shipping, accept purchase orders, and turn quotes around within 24 hours. Click Request a Quote to get started — pricing is never published here, since every quote reflects your specific configuration and timeline.

General Information about the Product
Part Number	IS215VCMIH1B Mark VI IS200
Description	IS215VCMIH1B by GE IS215VCMIH1BB Mark VI IS215 New Surplus Factory Package
Condition	newSurplusFactoryPackage Cleaned and Tested. With 1 Year Warranty.