The GE SPEEDTRONIC™ Mark VI Control System represents the evolution of over 30 years of turbine control excellence, providing a complete integrated control, protection, and monitoring solution for gas and steam turbines.
Engineered through deep collaboration between GE’s turbine design and controls engineering, the Mark VI ensures optimized turbine performance, system reliability, and seamless plant integration.

Designed for both generator and mechanical drive applications, the Mark VI also serves as an ideal platform for integrating balance-of-plant (BOP) and power island controls, delivering a true end-to-end control ecosystem.

⚙️ Key Technical Features

Advanced Control Architecture:
Offers both Simplex and Triple Modular Redundant (TMR) configurations—scalable from single-module to multi-rack distributed systems.
TMR design incorporates three independent control modules, power supplies, and IONets, ensuring continuous operation and fault isolation.
Software Implemented Fault Tolerance (SIFT):
Inputs are processed and voted in software across three modules for maximum reliability, enabling continuous turbine operation even with component failure.
High-Speed Data Exchange & Synchronization:
The system’s throughput supports up to nine 21-slot VME racks at 40 ms scan rates, ensuring ultra-fast feedback and stable turbine control.
Redundant Sensor Interfaces:
Supports single, dual, or triple redundancy for sensor configurations. Fault diagnostics distinguish between field sensor faults and internal electronics errors.
Output Voting Mechanisms:

3-Coil Servo Control for valve actuation.
2-out-of-3 relay logic for trip solenoids.
Median select on 4–20 mA or 0–200 mA control outputs for process reliability.

Self-Diagnostics & Predictive Alarms:
Continuous internal health monitoring with real-time alarm feedback for fault detection, predictive maintenance, and fail-safe operations.

Architecture & Redundancy Advantages

Configuration	Description	Fault Tolerance
Simplex	Single controller configuration for small systems.	Standard reliability
Dual Modular	Redundant I/O & controller cards with failover.	Medium
Triple Modular Redundant (TMR)	Three parallel control paths with SIFT voting logic.	Highest reliability and uptime

The TMR system can ride through a single point of failure while maintaining full turbine operation. Field repair and hot-swap capabilities further minimize downtime, ensuring maximum plant availability.

⚡ System Integration & Compatibility

Integrates seamlessly with Mark V, Mark VIe, and legacy GE control systems.
Compatible with GE Bently Nevada monitoring systems and Condition Monitoring platforms.
Interfaces with Modbus, Ethernet, and OPC protocols for plant-wide data integration.
Fully supports remote diagnostics, DCS connectivity, and balance-of-plant control integration.

Application Scenarios

Gas Turbines: Power generation, mechanical drive, co-generation systems.
Steam Turbines: Industrial power units, combined-cycle plants, process drives.
Oil & Gas: Compressor trains, LNG plants, refinery turbines.
Power & Energy: Thermal, hydro, and renewable hybrid plants.
Marine & Offshore: Drive and auxiliary turbine applications.

Why Choose the Mark VI System?

Proven reliability through decades of GE field experience.
High-performance TMR architecture ensures continuous operation.
Seamless integration with BOP systems & modern digital platforms.
Comprehensive diagnostics & predictive maintenance capability.
Supports remote monitoring, upgrades, and extended lifecycle support.

Mark VI vs Mark VIe — What’s the Difference?

The GE SPEEDTRONIC™ Mark VI and Mark VIe systems both offer robust turbine automation and protection.
The main differences lie in system architecture, communication protocol, redundancy flexibility, and integration capabilities, as summarized below.

Mark VI vs Mark VIe Turbine Control System Comparison

Feature / Parameter	Mark VI Control System	Mark VIe Control System
Generation	Third-generation GE SPEEDTRONIC™ turbine control	Next-generation evolution of Mark VI with Ethernet-based I/O
System Architecture	Centralized control using VME racks	Fully distributed, modular control using Ethernet I/O network
Redundancy Design	Triple Modular Redundant (TMR) architecture — 3 independent control modules, power supplies, and IONets	Supports Simplex, Dual, and TMR redundancy with flexible I/O configurations
Communication Protocols	Proprietary IONet, serial and Modbus RTU	Ethernet / Modbus TCP / OPC-UA for open integration and remote diagnostics
Control Hardware	VCMI-based VME cards for I/O and voting logic	Mark VIe I/O Packs (I/O Modules) with embedded processors and local intelligence
Software Platform	Software Implemented Fault Tolerance (SIFT) voting logic	Advanced fault-tolerant logic with enhanced diagnostic layers and cybersecurity
Scalability	Up to 9 VME racks, suitable for small–medium turbines	Modular expansion supporting multiple turbines and entire power islands
Integration Capability	Compatible with older GE Mark V and legacy systems	Native integration with Mark VIe HMI, ToolboxST™, and Bently Nevada monitoring
Maintenance & Diagnostics	Centralized diagnostics via controller modules	Distributed health monitoring, hot-swap modules, and online firmware updates
Cybersecurity	Basic user-level access and protection	Enhanced cybersecurity suite with role-based access, logging, and secure Ethernet
I/O Configuration	Analog, digital, and servo control via central rack	Intelligent Ethernet I/O packs — local processing near sensors/actuators
Data Throughput	~40 ms scan time for full rack cycle	High-speed deterministic Ethernet communication (<10 ms typical)
Remote Access	Limited remote access options	Full remote diagnostics and condition monitoring capability
Lifecycle & Support	Mature system — still widely used and serviceable	Current GE standard platform — active development and long-term support
Ideal Applications	Gas/steam turbines, mechanical drives, retrofits, existing Mark V upgrades	New power plant installations, digital retrofits, multi-unit control integration
Upgrade Path	Can be upgraded to Mark VIe using existing wiring and sensors	Native system for next-gen turbine control modernization

✅ Choosing Between Mark VI and Mark VIe

Choose Mark VI if you require a stable, field-proven system with existing GE turbine infrastructure or retrofit compatibility.
Choose Mark VIe for new installations or modernization projects needing Ethernet-based distributed I/O, enhanced cybersecurity, and digital integration with condition monitoring systems.
Both systems deliver GE’s proven TMR reliability, real-time control, and continuous turbine protection, but Mark VIe offers broader scalability and long-term lifecycle support.

FAQ

Q1: What is the difference between Mark VI and Mark VIe?

The Mark VIe is an evolution of the Mark VI system with Ethernet-based I/O, modular control, and higher scalability, but both share GE’s redundant control logic principles.

Q2: What does TMR mean in Mark VI control?

Triple Modular Redundant (TMR) architecture uses three independent control modules running in parallel. Inputs and outputs are "voted" among them to ensure continuous operation, even if one fails.

Q3: How does the Mark VI achieve fault tolerance?

Using Software Implemented Fault Tolerance (SIFT), inputs from all modules are compared and voted in real time, ensuring the correct data is used for processing even if one signal path fails.

Q4: Can the Mark VI be integrated with non-GE systems?

Yes. The Mark VI supports Modbus TCP/IP, Ethernet, and other standard communication protocols, enabling integration with DCS or third-party systems.

Q5: What are the maintenance and diagnostic capabilities?

Continuous self-checks, sensor voting, and diagnostic alarms help operators predict issues before failure, minimizing downtime.

Q6: What makes Mark VI suitable for turbine safety systems?

The system’s redundant servo control, dual/triple sensor configuration, and independent power paths ensure fail-safe turbine shutdown and trip reliability.