Key Technical Specifications
| Parameter | Detail |
|---|---|
| Part Number | IS215VCMIH2CA |
| Product Type | VME Communication Interface Card / VCMI Bus Master Controller |
| Compatible System | GE Speedtronic Mark VI Turbine Control |
| Form Factor | 6U VME board, 0.787 in. width |
| Processor | Texas Instruments TMS320C32 32-bit DSP |
| Memory | 32 KB dual-port memory; SRAM and flash (capacity varies by revision) |
| IONet Ports | 3× 10Base2 Ethernet (BNC), 10 Mbit/s |
| Serial Port | 1× RS-232C |
| Front-Panel LEDs | TX/RX/CD per IONet port; Run, Fail, Status, 1/2/4/8 |
| Backplane Connectors | 2× VME backplane connectors + 12-pin vertical connector |
| Redundancy Support | Simplex or TMR (Triple Modular Redundant) configurations |
| Operating Temperature | 0 °C to 70 °C typical (confirm against nameplate) |
| Reference Manual | GEH-6421 (Mark VI documentation family) |
Product Introduction
If you have ever stood in front of a Mark VI turbine cabinet with a tripped unit and a blank HMI, you know the VCMI card is where the blame lands first. The IS215VCMIH2CA is not an I/O card and it is not a CPU in the PLC sense. It is the VME bus master and IONet gateway for the Mark VI Speedtronic system. Every I/O board in the rack talks through it, and every peer controller in a TMR triplet exchanges data over those three 10Base2 BNC ports.The “CA” suffix matters. It is a VCMIH2-family board with three IONet ports, meaning it is intended for TMR or multi-redundant configurations. If your rack was built with a single-port VCMIH1, dropping an H2CA in without verifying the application configuration can leave you with unused ports and mismatched node IDs. The board runs a TI DSP, manages board identification on the VME backplane, and handles the deterministic timing that turbine control demands. It is old architecture by today’s standards, but it is proven, and plants keep these in service because replacing a Mark VI rack is a project, not a parts order.
Quality SOP & Tech Pitfalls
The Lab Report (SOP)
- Visual and counterfeit check: verify GE labeling, part number IS215VCMIH2CA, board revision, and BNC connector condition. Reject boards with cracked solder joints around the BNC ports or oxidized backplane pins.
- Backplane inspection: check both VME connectors and the 12-pin vertical connector for bent pins. A single bad pin can kill IONet communication on one channel.
- Power-up in VME chassis: seat the card in a compatible Mark VI rack; apply rack power; verify Run LED behavior and absence of Fail indication.
- IONet link test: connect known-good 10Base2 coax segments; verify TX/RX/CD LEDs on each port.
- Serial port check: verify RS-232C communication if used for configuration or diagnostics.
- Configuration capture: record board revision, node ID settings, LED status, and serial number before packing.
Do not test this card in isolation. It requires the Mark VI VME backplane and proper rack power.The Engineer’s Warning (Pitfalls)The most common field error is mixing VCMI revisions. An H1 board has one IONet port; an H2/H2CA has three. Swapping them without updating the application configuration will produce communication faults that look like cable problems. Also, 10Base2 coax networks are unforgiving about termination. A missing or failed 50-ohm terminator at the end of an IONet segment will bring down the entire network, and the VCMI will report it as a peer failure.Another pitfall: assuming IS215VCMIH2CA and IS200VCMIH2CAA are always interchangeable. The IS200 prefix typically denotes the packaged/board assembly level, while IS215 denotes the bare PCB level within the Mark VI family. They are related, but you must confirm the revision chain and any conformal coating or hardware differences before substitution.
Installation & Configuration Guide
Pre-Installation⚠️ Follow site lockout/tagout procedures before working in the turbine control cabinet.
⚠️ Photograph the existing VCMI card, slot position, node ID jumpers or switches, and all coax and serial connections.
⚠️ Record the IONet segment topology, terminator locations, and peer controller addresses from the Mark VI application software.
Verify the replacement board revision matches the original (H2CA for 3-port TMR configurations).RemovalLabel the slot position and all coax cables. Disconnect the 10Base2 BNC connectors and RS-232C cable. Release the card retention hardware. Pull the VCMI card straight out of the VME backplane. Do not rock it.InstallationAlign the IS215VCMIH2CA with the same VME slot. Seat it firmly until both backplane connectors are fully engaged. Reconnect the BNC coax cables to the correct IONet ports. Verify 50-ohm terminators are present at both ends of each IONet segment. Reconnect the RS-232C cable if used.Power-On & TestingRestore rack power. Verify Run LED is steady and Fail LED is off. Check TX/RX/CD LEDs on each IONet port for active communication. Confirm peer controller synchronization in the Mark VI application. Monitor for at least one full control cycle before declaring the replacement complete. If the unit is in TMR, verify all three controllers are in sync and no majority-vote faults are present.
Compatible Replacement Models
| Compatibility Tier | Model | Notes |
|---|---|---|
| ✅ Drop-in Replacement | IS215VCMIH2CA (same revision) | Match part number and revision; no reconfiguration needed |
| ⚠️ Functional Equivalent | IS200VCMIH2CAA | Related assembly-level part; confirm revision chain and hardware compatibility before substitution |
| ⚠️ Same Family | IS215VCMIH2C / IS215VCMIH2CC | Same VCMIH2 family; verify firmware, memory, and application compatibility |
| ❌ Not Directly Compatible | IS215VCMIH1 (single-port), Mark VIe IS215U/UCVE family | Different architecture or port count; requires re-engineering |
Frequently Asked Questions (FAQ)
What is the difference between IS215VCMIH2CA and IS200VCMIH2CAA?
The IS215 prefix typically refers to the PCB level, while IS200 refers to the packaged board assembly within the Mark VI product structure. They are closely related, but you must confirm the exact revision and any conformal coating or connector differences before swapping.Can I replace a single-port VCMIH1 with this H2CA card?
Not without verifying the application configuration. The H2CA has three IONet ports for TMR; the H1 has one. The Mark VI application must be configured for the correct VCMI type and IONet topology.Why are all three IONet LEDs not lit?
In a TMR configuration, each IONet port connects to a different peer controller or network segment. If a port is unused or the coax segment is unterminated, the LED will not show activity. Verify the site topology before assuming a fault.Does this card run the turbine control application?
No. The VCMI card handles VME bus mastering and IONet communication. The control application runs on the main processor modules (UCPU/UCVE family) in the Mark VI rack.Is 10Base2 still supported?
Yes, within the Mark VI system. The IONet network uses 10Base2 coax with BNC connectors. Do not attempt to substitute Ethernet switches or Cat5 cabling on the IONet segments.Can I hot-swap this card?
Not recommended. The VCMI card is a bus master and IONet gateway. Removing it during operation can disrupt communication across the entire rack. Follow site procedures for controlled replacement.Do you provide application configuration?
Standard supply includes power-up and communication verification. Mark VI application loading, IONet configuration, and TMR synchronization must be performed by qualified personnel using GE Mark VI tools.
