from the control department...
GE speedtronics
Power generation equipment control. topic
Posted by saleem on 13 June, 2011 - 2:40 am
What is MarkVI, is it a DCS/PLC/BMS/SCADA?
or its Is some thing other than all these?
if mark VI is different than all these what is this called then?

Please give me the correct answer.

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Posted by CSA on 13 June, 2011 - 11:18 am
Technically, the Mark VI is no longer currently in production, though some of GE's companies seem to still be shipping turbines with Mark VI control systems probably using the last of their store of Mark VI components.

The digital control system known as the Mark VI Speedtronic (though I'm being admonished that GE is dropping the use of the term Speedtronic...) is a purpose-built digital turbine control system. That means it is purposely designed to control, protect and monitor turbines and the driven devices they provide torque to, including the auxiliary devices used to operate the turbines and driven devices.

A turbine control system is different from other digital control systems in that it has the inherent, built-in capability to deal with the types of inputs and outputs typically found on turbines which operate at high speeds. Yes; many digital control systems can monitor speed, but turbine speed control requires very high-speed sensing and control outputs to prevent overspeed conditions and provide stable power output (torque production) that most digital control systems can't do without special, unique and sometimes proprietary interface modules.

One of the reasons the Mark VI was developed, in addition to a need for more I/O than the Mark V was capable of handling, was to be used as a BOP (Balance of Plant) control system for the heat recovery steam generator (HRSG) and its auxiliaries for the GE single-shaft steam- and gas turbine H-class machines. (Another term used for BOP control systems is DCS, or Distributed Control System.) Instead of trying to work with another control system vendor to integrate the HRSG controls with the Speedtronic controls for the GT and ST, GE wanted to have a single control system, and operator interface, for the entire plant.

Also, GE wanted to be able to offer a BOP, or DCS, control system to other plants. Many Customers want a single control system and interface for the equipment in their plant, instead of a myriad of multiple control systems and operator interfaces which are usually integrated with very mixed results. A single control system and interface (ostensibly) makes maintenance and troubleshooting easier, reduces spare parts inventory, and reduces the need for training people on multiple control systems.

As opposed to previous Speedtronic control systems, the Mark VI (and the Mark VIe) can take many forms and come in many different sizes and shapes. Also, as opposed to previous Speedtronic control systems, the Mark VI (and the Mark VIe) can be "distributed", meaning that all of the control system equipment does not have to be located in a single physical location; some I/O components can be located remotely and connected do the main control processor(s) via cabling (usually Ethernet cabling, either copper or fiber optic).

In the strictest sense of the term, it is ***NOT*** a PLC (Programmable Logic Controller). It would not be advisable to use a Mark VI to control conveyors in a warehouse, nor would it be advisable to use a PLC to control and protect a turbine and its driven devices. The types of inputs and outputs for the two applications are very different, and the processing of the inputs and outputs also requires very different control systems.

The Mark VI (and Mark VIe) can be used as a BMS (Burner Management System), but that's not a common application.

SCADA? That's a very nebulous term, and in my experience it refers to software applications that gather and provides data from various remote locations and sources via a single user interface. I wouldn't go so far as to say it's a "SCADA system", though I believe the main component of the operator interface (HMI) of the Mark VI (and Mark VIe) is a software application called (in polite company) CIMPLICITY which is and has been marketed as a SCADA application. BUT, the implementation of CIMPLICITY used on GE turbine control systems is a special-case application of that package, and doesn't lend itself very well to "expanded" usages.

And now to answer your next question: What is this Mark VIe? The Mark VIe is the next-generation Mark VI, that has enhanced distributed input/output capability. It uses many of the same input/output terminal boards used in Mark VI systems, but also has some new input/output terminal boards specific to the Mark VIe. It also uses a different architecture/topology for interconnecting the terminal boards to the main control processor(s) (though it's again copper and/or fiber optic Ethernet-based). It also uses a different programming-, configuration- and troubleshooting application than the Mark VI (called ToolboxST). (NOTE: Apparently, GE is working to integrate Mark VI applications which previously required "legacy" Toolbox into TooboxST, so that only one application could be used for both control systems on some sites with certain hardware.)

So, to sum up: The Mark VI (and Mark VIe) are digital control systems, primarily purpose-built for the control and protection of turbines and their driven devices and auxiliaries, but, which can be adapted to other power plant applications, including BOP and BMS applications very easily. If the power plant uses GE-design turbines then using a Mark VI (or Mark VIe) as the digital control system for other equipment in the plant makes integration much easier, and has many benefits for the people operating, maintaining and troubleshooting the plant.

GE are very keen to start expanding the application of Mark VIe to turbines other than GE-designed.

Posted by JE on 18 August, 2011 - 5:59 pm
I am the Product Line Leader for Services at GE Measurement and Control Solutions. I just wanted to make one clarification. The Mark VI, nor the Mark V, are "out of production". Users can purchase spare parts, receive technical support, etc for both platforms. While it is true that the platforms are not used on new production turbines, the Mark VI is still supplied on retrofits based on customer preference. GE still supports the Mark V which was developed in the 90's and will have support alternatives going forward.

If you are a turbine operator, business associate or EPC firm, you can go to for more information via our Controls Connect portal. You will need to register but it is a fairly quick registration. Once you register, it should be a short time to get access to the system. In Controls Connect you can either search the knowledge database for similar issues, find manuals, TILS, white papers, etc or phone/email the technical support directly. There is no cost for this service. Feel free to contact me if you have any questions I hope this helps.

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Posted by controlmech on 13 June, 2011 - 11:24 am
The Mark VI is a controller/control system developed by GE primarily for use on its steam and gas turbines. The system has been upgraded through the years. The current system is MKVIe. It provides for simplex, redundant, and triple redundancy for IO and control processors. The redundancy can be mixed in the system. The goal is to expand the applicability of the MKVIe to more than the core steam and gas turbine application. By allowing for mixed levels of redundancy in a single system the $/IO can be reduced for non-critical control and monitoring I/O.

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Posted by otised on 13 June, 2011 - 11:26 am
Mark VI Speedtronic is a GE turbine (gas and steam) control system. The current version is Mark VIe which has features that make it look more like a DCS than previous versions. Still, it is primarily for gas and steam turbine, HRSG, and balance of plant control in simple cycle or combined cycle power plants and for steam turbine control in conventional steam plants using GE steam turbines. As far as I know, it is not sold as a DCS or control system for other applications. GE's CM&U (Conversions, Modifications and Upratings) organization MAY use it for control of non-GE turbines as part of an overall conversion that involves new GE equipment being added to an existing power plant.

Posted by Capucho on 14 June, 2011 - 8:20 am
I have heard that GE only recently expanded its Mark VIe as plant DCS (ICS, Integrated Control System). What does this comprise? Is it another expansion of its previous system? What is new?

Posted by CSA on 14 June, 2011 - 2:23 pm
Do you believe everything you hear?

GE has used the Mark VI as DCS, and is continuing and even expanding that usage with the Mark VIe. The Mark VIe has a smaller "footprint" for many applications and so lends itself to easier implementation in distributed applications (meaning that some of the I/O terminal boards and associated hardware can be more easily remotely mounted, greatly reducing the cost for interconnecting wire and cable and terminations).

There are many more "general-purpose" modules available for the Mark VIe for DCS applications than were available for the Mark VI. (Profibus, CANnet, etc., just to name a couple of them). So, GE is, indeed, expanding their ability to interface with a wider variety of the types of instruments and topologies commonly found in power plants and other related applications.

Hope this helps!

Posted by Demigrog on 14 June, 2011 - 10:51 pm
As CSA pointed out, the Mark VI has been used for BOP/DCS applications, and the Mark VIe was designed with BOP in mind. It is also true that later versions of the Mark VIe and ToolboxST are better suited for DCS applications; around ControlST V3.3, a whole lot of work was done. The key enhancements that came out of that were the CIMPLICITY advanced viewer, the new DCS function block library (with animated block shapes in the logic diagrams), analog alarms, and several new I/O packs. More DCS-centric features are added every year; for example this year they added FOUNDATION Fieldbus (with a new I/O pack, the PFFA, acting as the Linking Device).

Aside from BOP in thermal plants (a natural adjacency to turbine controls), Mark VIe is also used for Solar, Wind, Nuclear, and Oil&Gas DCS projects.

On your other question, the OC6000 DCS, good luck figuring that one out, as I doubt many people at GE know either. GE bought a Chinese DCS manufacturer, XinHua, and has been integrating it with their other controls products. IMO, these products are intended mostly for the Chinese market, so GE can meet local content laws. I'm sure they'd be happy to sell it anywhere, though. :)

Posted by Capucho on 14 June, 2011 - 10:54 am
Another question: What makes the difference between GE's Mark VIe as Plant DCS and OC6000e? Thanks!

Posted by CSA on 14 June, 2011 - 2:12 pm
Sometimes different divisions of the same company have competing products. And this is one of those situations.

The OC6000 and OC6000e were never designed as turbine control systems, more as "enhanced" PLCs to be used as DCSs (Distributed Control Systems). The hardware is very different, in many, many ways.

I have been told that it uses EGD; but I've also been told it doesn't. I've been told that it can be configured/programmed with some versions of ToolboxST, but that some versions of ToolboxST don't work with it.

I have no personal experience working with OC6000 or OC6000e, but, I'm told that for some applications it is more than adequate and has worked very well.

It's like anything else when it comes to choosing one system over another: Most systems will do just about anything they can be programmed to do. The real choice should be about the company or entity that is providing the programming, installation, and after-installation service and support. Do they have the experience to do what they say they can do? Will they be around in two years, or eight years, or twelve years? Do some research; ask for references, and don't be afraid to contact the references and ask pointed questions about the service and support, not just about the control system.

It's been said many times on The real cost of a control system is NOT the upfront sales price; it's in the details of installation and service and support.

These two control systems are no different in this respect.

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