Calibration of LVDT on MK-VI simulator

S

Thread Starter

samson16

Hello there,
While trying to demonstrate Regulators calibration on Mark-VI simulator, we are getting an alarm: "Calibration Mode Bit not set in Channel R" and comes out saying "Could not achieve Calibration Mode".

Any clue what this calibration mode bit is? and how to set it?

Regards,
Samson
 
In the 'Card Points' section of the VSVO card there will be fields for 'Calib Enable #' where # is the number of the servo regulator you intend to calibrate. Typically there are signals assigned to these fields like L3ADJ# (again where # is the number of the regulator). These points must be forced to 1 for the permissive to enable calibration mode on that servo regulator.
 
Just because one is using a Mark VI "simulator" (there are several versions of the "simulator) doesn't mean any of the usual processes and procedures are different (other than the difference between a TMR and a SIMPLEX Mark VI).

To perform an LVDT calibration on most--but not all--Mark VI turbine control systems one has to manually force the CalibEnable logic to "1" for the associated regulator. (Some Mark VI panels had some logic that automatically set the CalibEnable logics to "1" based, usually, on speed being less than some value.)
 
Hi,
I did force the "Calibration enable logic" L3adj1 to '1', only then it accepted calibration mode, but after that when I click on "ON" I get this error message and all other buttons for 'calibrate sequence like " MIN END POS" and "MAX END POS" remain grey.

>Just because one is using a Mark VI "simulator" (there are
>several versions of the "simulator) doesn't mean any of the
>usual processes and procedures are different (other than the
>difference between a TMR and a SIMPLEX Mark VI).
>
>To perform an LVDT calibration on most--but not all--Mark VI
>turbine control systems one has to manually force the
>CalibEnable logic to "1" for the associated regulator. (Some
>Mark VI panels had some logic that automatically set the
>CalibEnable logics to "1" based, usually, on speed being
>less than some value.)
 
samson16,

You haven't told us where you obtained this "simulator" and what it is comprised of.

But, unless the software running in the "Mark VI" portion of the simulator has been configured to simulate hydraulic actuators and LVDT feedback during calibration (which most of the simulators I've seen are not so configured) then it's not going to be possible to do an AutoCalibration, or even a Manual positioning (stroking) of a servo-operated device. The best you can hope for--under most of the Mark VI simulations I've seen (ones provided by the turbine control system OEM) don't have this capability.

Let's take a look at what the "simulator" must do to simulate LVDT calibration or device stroking. Once enabled and activated, the servo-output to the actuator must drive the simulated LVDT feedback to the minimum- or maximum position and that feedback must be recognized by the firmware on the VSVO "card" and when it stops changing for some period, then the associated button will change color. This is true for both positions (minimum and maximum). This means there must be software running in the Mark VI simulator to accomplish this task. Just because the turbine can be started and stopped doesn't mean this off-line task was configured to be operational.

So, this seems like a misunderstanding of what the "simulator" is capable of doing--or perhaps, there is some internal logic that must be enable to allow this to happen (I've seen this on one OEM simulator), but it had to be forced (using Logic Forcing) until a display was created to be able to enable the functions with a button click (why that wasn't done by the OEM is anyone's guess).

Again, this is either a misperception or a lack of understanding of how to enable the required functions (if they even exist).

Have you monitored the servo-valve output "current" when you enabled the logic to see what it's doing when you're attempting LVDT calibration? Is it going to saturation? If so, what's happening to the LVDT "feedback" as the "current" is changing?
 
Hi CSA,

Thank you for your time in addressing the issue. In the first place, let me admit that I have limited knowledge on the capabilities of this simulator.

This is a GE's simulator VMWare based (software based and has no hardware associated). It simulates by default a FR-7FA GT.

Regarding calibration, up on forcing the enable logic (L3ADJ1 to 1) only the 'ON' button appears active, but it doesn't really activate the calibration mode, as it gives an error message (Calibration mode Bit not set in Channel R) on clicking Calibration 'ON' button. No clue what this Calibration mode Bit is?

As I am unable to enter calibration mode, I don't see any changes in Reg1 Ref (remains at -40), LVDT Feedback at 0 and servo current at 80. As you rightly mentioned, since there is no hardware / software associated to simulate the LVDT feedback, simulation of Auto calibration may not be possible.

Operation point of view this simulator works well, but again limited to a Fr-7FA only. Capability to switch models (Fr-5, Fr-6, Fr-9) would have been quite useful.

Could you please advise if any better Mark-VI or Mark-VIe simulators are available for sale (whether OEM or non-OEM).
Regards..
 
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