I want to what these signals mean and their role
L83FG- Increase Gas Fuel (does this literally increase fuel?) it is confusing
L84TG- On total gas fuel - The literal meaning is the machine is on complete gas fuel. But this is TRUE even in shutdown condition and Gas fuel is selected.
L43FTG- Fuel Transfer to gas - I never understood this. Does it says/is TRUE when unit is transferring to gas fuel from liquid fuel/mix fuel.

For all the above the description is misleading or i understand it wrongly.

L43FG- Gas fuel selected -this is clear
L43FG_PRSET- Gas fuel selection preset
L43FG_PERM- Gas fuel selection permissive

How the above signal works and how it gets co-related in command state block and how this block functions? I have read the block help but that did not help me.

Thanks
Suds

 

Are you asking if someone can please explain how these particular signals work?

There is something you need to know about the "longname" descriptions of GE-design heavy duty gas turbine control systems: They ARE NOT 100% correct. One should read them and in conjunction with analyzing the rungs/function blocks they are appear in decide if the signal name is appropriate or not. Without being able to review the application code running in the machine you are attempting to understand there is no way we can say with any degree of certainty precisely what the signal name means and how it's used.

L83FG usually means the amount of gas fuel the machine is burning can be increased, and it can also mean that gas fuel has been selected (meaning that it's possible to operate on gas fuel AND that gas fuel has been selected by the operator or the application code (through or in conjunction with the Command State Block)).
L83TG usually means the machine is operating with 100% gas--but it has been known to be used in other ways.
L43FTG usually means that a transfer to gas fuel is allowable, but it has also been used to mean a transfer to gas fuel is under way. Some machines have the ability to burn two different fuels (gas and liquid)--this is called mixed fuel operation--and sometimes when a transfer to gas fuel has been selected and "paused" (to operate on a mix of gas and liquid fuels for a period of time) L43FTG is a logic "1".

L43FG -- you got this one, you say. A 43 device (or a device with a number of 43) in GE-speak is the device used to select something; it's like a pushbutton or a bat-handle switch. To select gas fuel for example, one has to click on GAS from the fuel selection menu on the main display--which momentarily sets L43FG to a logic "1" to begin the process of selecting liquid fuel (when another fuel is currently selected) and if all of the permissives are met then eventually L83FG will be set to a logic "1". An 83 device is one that is set when something has been selected and is allowed/permitted (for example, for gas fuel it would be something like gas fuel pressure is above some minimum value which would allow gas fuel to be selected, so L43FG begins the process of checking to see if it's possible to switch to gas fuel, and if all of the permissives are met then L83FG will become a logic "1" and the process of switching to gas fuel will be allowed.
L43FG_PRSET is a logic value that automatically switches to gas fuel, like, for example, if liquid fuel supply pressure were to drop below a minimum value than a transfer to gas fuel would be automatically initiated.
L43FG_PERM is logic value that will allow gas fuel to be selected, either manually or automatically. Machines which can't burn gas fuel will have this logic signal permanently set to logic "0" to prevent selecting gas fuel (but all of the logic/rungs for gas fuel will still be present, because this is GE's way of making one "master" set of logic and then configuring it for something less than the maximum permissible options. It is a way of enabling and disabling options. These are two examples of how this PERM logic is used, but there can be others. For example, if a gas compressor is required to boost the gas fuel supply pressure to burn gas fuel in the machine L43FG_PERM might include a signal or signals that say the gas compressor is ready to run or is running so operation on gas fuel is permitted.

But, AGAIN, the only way to know exactly for sure what these signals mean on ANY site or for any particular machine is to review the logic to see how the signals are used, and if the longname description is correct for that site or not. (In the signal definition is where the longname description is placed/written; it can be edited if necessary, with the proper passwords and with knowledge of how to complete the process of changing/modifying the longname description and getting it into the global data dictionary (as it used to be called).

That's all that can be said without being able to review the application code in the machine at your site.

This is a free forum--meaning that responders get paid exactly the same amount as questioners pay for posting their problems or requests for information or help with understanding and resolving an issue: Zero. Nada. Niente. Zilch. So, asking politely for help (by using 'please') is very much appreciated. (I know; it's not a thing in some parts of the world, but it could be--and it is a thing in most parts of the world). Being pleasant and cordial is much appreciated on Control.com. As is timely feedback--you can even say if the help wasn't useful, but it helps if you say why it wasn't useful as we use that in trying to provide clarification and improving answers in the future.

 

By the way, can you please explain what 'viz' means and how you're using it?

THANK YOU!

 

The Command State block is not the easiest thing to understand, but it's not impossible to understand, either.

There are two groups of inputs on the left, and a group of outputs on the right (common for GE algorithms/blocks--inputs on the left and outputs on the right, meaning the block operates "from left to right").

I believe there is a mask Control Constant that is used to permit the passing of inputs on the left into the block for internal operation.

There is usually logic (rungs; function block diagrams) that control the logic states of some of the inputs on the left. In the case of fuel selection, there are likely some inputs controlled by the 'targets' on the fuel selection area of the main graphical user interface display. So, L43FG would typically be associated with the GAS fuel selection target and clicking on that target would set L43FG to a logic "1" for the period of time specified for the target in the display configuration. L43FL might be used for liquid fuel (distillate, for example) and the LIQ or DIST target of the fuel selection area of the main display would, when clicked on and released, woulc set L43FL to a logic "1".

If the mask constant values are correct for passing these logic signals into the Command State Block then they would be further "analyzed" based on the PERM values in the lower group of inputs. So, if L43FG_PERM were set to a logic "1" and the mask constant values for the PERM values are correct (to allow L43FG_PERM to pass into the fuel selection Command State block for internal operation) then the fuel selection of Gas Fuel would be permitted to occur, and L83FG would be set to a logic "1" on the output of the block, and that logic signal than goes to other rungs/function block diagrams to facilitate selecting or transferring to gas fuel.

The commissioning field service technician should be testing this during commissioning and initial operation. When it works correctly, suffice it to say that when permitted the fuel selected by clicking on the associated target on the graphical user interface display will result in that fuel being set to be the fuel to be operated on, or transferred to.

The L43FG_PRSET value will sometimes be used to automatically change to gas fuel--such as when liquid fuel supply pressure is drops below some value. L43FL_PRSET will sometimes be used to automatically change to liquid fuel--such as when the gas fuel supply pressure drops below some value.

That's about it. One of the other outputs of the Fuel Selection Command State Block is a value that can be used to display the selected fuel in word form on a graphical operator interface display (such as in one of the Status Fields of the main display).

Again, the commissioning person at site should be checking the proper operation of this, and other, command state blocks. (Actually what will probably happen is that IF THERE IS A PROBLEM during commissioning/initial operation then the commissioning person will be forced to review and try to fix the problem.

The above was written without being able to physically see a command state block (I don't have access to any application code at the present time). So, while it may not be 100% correct for internal operations, the basic operation is as described.

If you need clarification (not doubts--clarification) post a picture of the command state block and provide the value of any mask Control Constant applied to the block.

 

By the way, can you please explain what 'viz' means and how you're using it?

THANK YOU!

formal writing to introduce a list of specific items or examples or to clarify or explain something that has been previously mentioned (i mentioned it for SIGNALS)

Thanks

 

Are you asking if someone can please explain how these particular signals work?

There is something you need to know about the "longname" descriptions of GE-design heavy duty gas turbine control systems: They ARE NOT 100% correct. One should read them and in conjunction with analyzing the rungs/function blocks they are appear in decide if the signal name is appropriate or not. Without being able to review the application code running in the machine you are attempting to understand there is no way we can say with any degree of certainty precisely what the signal name means and how it's used.

L83FG usually means the amount of gas fuel the machine is burning can be increased, and it can also mean that gas fuel has been selected (meaning that it's possible to operate on gas fuel AND that gas fuel has been selected by the operator or the application code (through or in conjunction with the Command State Block)).
L83TG usually means the machine is operating with 100% gas--but it has been known to be used in other ways.
L43FTG usually means that a transfer to gas fuel is allowable, but it has also been used to mean a transfer to gas fuel is under way. Some machines have the ability to burn two different fuels (gas and liquid)--this is called mixed fuel operation--and sometimes when a transfer to gas fuel has been selected and "paused" (to operate on a mix of gas and liquid fuels for a period of time) L43FTG is a logic "1".

L43FG -- you got this one, you say. A 43 device (or a device with a number of 43) in GE-speak is the device used to select something; it's like a pushbutton or a bat-handle switch. To select gas fuel for example, one has to click on GAS from the fuel selection menu on the main display--which momentarily sets L43FG to a logic "1" to begin the process of selecting liquid fuel (when another fuel is currently selected) and if all of the permissives are met then eventually L83FG will be set to a logic "1". An 83 device is one that is set when something has been selected and is allowed/permitted (for example, for gas fuel it would be something like gas fuel pressure is above some minimum value which would allow gas fuel to be selected, so L43FG begins the process of checking to see if it's possible to switch to gas fuel, and if all of the permissives are met then L83FG will become a logic "1" and the process of switching to gas fuel will be allowed.
L43FG_PRSET is a logic value that automatically switches to gas fuel, like, for example, if liquid fuel supply pressure were to drop below a minimum value than a transfer to gas fuel would be automatically initiated.
L43FG_PERM is logic value that will allow gas fuel to be selected, either manually or automatically. Machines which can't burn gas fuel will have this logic signal permanently set to logic "0" to prevent selecting gas fuel (but all of the logic/rungs for gas fuel will still be present, because this is GE's way of making one "master" set of logic and then configuring it for something less than the maximum permissible options. It is a way of enabling and disabling options. These are two examples of how this PERM logic is used, but there can be others. For example, if a gas compressor is required to boost the gas fuel supply pressure to burn gas fuel in the machine L43FG_PERM might include a signal or signals that say the gas compressor is ready to run or is running so operation on gas fuel is permitted.

But, AGAIN, the only way to know exactly for sure what these signals mean on ANY site or for any particular machine is to review the logic to see how the signals are used, and if the longname description is correct for that site or not. (In the signal definition is where the longname description is placed/written; it can be edited if necessary, with the proper passwords and with knowledge of how to complete the process of changing/modifying the longname description and getting it into the global data dictionary (as it used to be called).

That's all that can be said without being able to review the application code in the machine at your site.

This is a free forum--meaning that responders get paid exactly the same amount as questioners pay for posting their problems or requests for information or help with understanding and resolving an issue: Zero. Nada. Niente. Zilch. So, asking politely for help (by using 'please') is very much appreciated. (I know; it's not a thing in some parts of the world, but it could be--and it is a thing in most parts of the world). Being pleasant and cordial is much appreciated on Control.com. As is timely feedback--you can even say if the help wasn't useful, but it helps if you say why it wasn't useful as we use that in trying to provide clarification and improving answers in the future.

WTF?
Thank you for your efforts to reply. I got to understand the functions of those signals. To say precisely, the description used for those signals are really confusing. I got cleared. I tried to attached snapshots of the logic, even 1.97MB is also getting attached. What is the max size of the file that can be attached ?

Thanks
Suds

 

hello,

the maximum attachment size is 2000 kb

bertus

 

Do not accept everything I write about longnames as gospel. GE has a proven track record of making me wrong. (It's nothing personal; it's just that the only standard that exists for signal naming conventions is: "There is no standard." That would be too difficult to document and enforce.)

The ONLY "document" that defines what a signal means and does is the application code. You probably got those longnames from looking at the application code, but it's the rungs/function block diagrams/blocks that define what a signal does. Remember: L43FTG is just an alias for 1B79 (an example), a hexidecimal address. L43FTG is a convenient way for humans to recognize what 1B79 might be used for (well, some humans, anyway ;-) ).

When I want to attach something like a photo or a .pdf or a scanned document or a .jpeg I just copy and paste it directly into the response. I don't know what the size limitations are; I've never run into them. There are tools in the toolbar at the top of the response box, but I've never used them (maybe I should.?.?.?).

 

hello,

the maximum attachment size is 2000 kb

bertus

Hey Bertus, Thanks for the info !!

 

Do not accept everything I write about longnames as gospel. GE has a proven track record of making me wrong. (It's nothing personal; it's just that the only standard that exists for signal naming conventions is: "There is no standard." That would be too difficult to document and enforce.)

The ONLY "document" that defines what a signal means and does is the application code. You probably got those longnames from looking at the application code, but it's the rungs/function block diagrams/blocks that define what a signal does. Remember: L43FTG is just an alias for 1B79 (an example), a hexidecimal address. L43FTG is a convenient way for humans to recognize what 1B79 might be used for (well, some humans, anyway ;-) ).

When I want to attach something like a photo or a .pdf or a scanned document or a .jpeg I just copy and paste it directly into the response. I don't know what the size limitations are; I've never run into them. There are tools in the toolbar at the top of the response box, but I've never used them (maybe I should.?.?.?).

WTF?
You are right, this may be coz they want to keep the understanding among themselves and only few outside. Also there is a possibility that the codes are written in different countries and they might be writing the descriptions at their level of English.

Thanks for reply..
Suds

 

It's because there is ZERO review of signal naming and descriptions. And when signals get changed for any reason, there is nothing that obligates the person making the change to modify the longname description to match the new function. When the Mark* IV was being developed there WAS some very tight control of signal naming in the beginning (because it was essentially GE's first digital, programmable turbine control system (yes, the Mark* II with ITS was programmable, but ONLY the water injection capability for all intents and purposes).

There is NO training, no review, no oversight, no written procedures or requirements. And, when field service people make changes in the field (which doesn't happen much anymore--for a variety of reasons) they have even less training and even less oversight and review.

It's pretty sad, actually. You give them too much credit for trying to "hide" functionality. You will probably be amazed at the number of signals names that have NO longname description as you dig deeper into the application code, especially if the machine has any non-standard auxiliaries or control schemes.

And, yes, there is now some level of English proficiency involved, though mostly that just results in poorly chosen signal names AND NO longname description(s).