We have a unit with a Control Constants display problem. We would like to be able to adjust the constant K63GSD_S1, but find that this is not available on the constants display. This constant exists in the CSP and the UNITDATA.DAT file and the FACTORY.ASG file but not in the CONST_Q.SRC file, nor in the SITE.ASG file. How do I get this constant onto the display list to make it adjustable?

 

Does your unit use an <I> or a GE Mark V HMI for control and monitoring of the unit?

Is your unit a GE-design heavy-duty gas turbine or an aeroderivative turbine?

There were some Control Constants which were not meant to be field-adjustable and they were blocked from the Control Constant display to prevent operator adjustment. (Usually, this was only done with aeroderivative, or LM, units.)

There was another posting here on control.com in which the originator learned that a new Control Constant display executable was required after an upgrade (http://www1.control.com/1026229620/index_html).

(The search feature of control.com is one of the best of any forum on the Web! This was found using 'control constant display'...)

If neither of the above is the problem, then the problem may be that the Control Constant does not exist in F:\UNIT1\CONSTSET.DAT (presuming we are talking about the configuration for a Mk V in the UNIT1 directory). In later versions of <I> and GE Mark V HMIs, before any Control Constant could be adjusted it had to be listed in a file called CONSTSET.DAT.

If your unit has a GE Mark V HMI, you can find information on the file and the utility used to create it in the GE HMI for Speedtronic(tm) Turbine Controls Application Manual, GEH-6126.

markvguy

 

Whoops! This author misread the original post!

All variable values are not Control Constants. If the signal definition does NOT exist in CONST_Q.SRC, then it's NOT a Control Constant. There must be something in the CSP writing the value of the signal which is then used as the setpoint for some control scheme.

You should consult GE for assistance with whatever problem it is believed that changing the value of K63GSD_G1 will solve. If the value is being written to by some sequencing and is NOT in CONST_Q.SRC, then it was not meant to be adjusted.

markvguy

 

markvguy,

Thanks for the quick reply. Ge (nuovo pignone) will be contacted regarding this problem.

Since the point is defined in the FACTORY.ASG file, and is also defined and scaled with a hex address in the UNITDATA.DAT file, then surely it can be added to the CONST_Q.SRC file to be made adjustable and added to the variable constants.

 

Hello.

Just a note to add to what Mk5guy has told you, which of course is entirely accurate as always.
You should certainly not try to add this point to Const_Q.src. As Mk5guy says its probably not meant to be adjusted.

You should check whether this point is written to. There are quite a few points that look like constants but in fact are written to by other points. An easy way to check this is to look at the CSP. There will be a list of all the places that this point occurs. If there is a Dash in front of it then this denotes the place that this point originates. You will notice that none of the control constants have a dash in front of them because they originate in Const_q.src, but points that are created in sequence have a dash to show you where they are "born".

If your point has a dash in front of it then you know it is written to. Go to that place in sequence and it should be easy to see what writes to it. You then may find that you can adjust a constant that does write to your point. It's been a while since I worked on MK 5 so treat this with caution but Mk5guy may be able to confirm what I say.

I hope this is of some use.
Good luck.