Plotting hystersis loop

[Thuriya82]

Hi,

I am a new in LabVIEW . I want to control a power supply (BK PRECISION XLN 8018) and lock in amplifier ( PerkinElmer 7225 DSP LOCK-IN AMPLIFIER) by labVIEW. The lock-in amplifier is connected whith a photo diode and chopper.

I want to use labVIEW to plot a hysteresis loop for my sample. Could you help me how can I construct a program in labVIEW to do that?

Regards,

Thuraiya

[GerdW]

Hi Thuriya,

welcome to the forum!

how can I construct a program in labVIEW to do that?

At first you need some routines (VIs) to communicate with your devices.

Then you need to collect the measurement data before you plot them in a XY graph…

I am a new in LabVIEW .

Then you should take all those free resources offered by NI.

You should also check the Instrument Driver Network to look for suitable device drivers.

[Thuriya82]

Hi,

I borrow KEPCO POWER SUPPLY because it is bipolar .

I want to use the attached VI of KEPCO with another one of the lock-in amplifier. I cannot decide which VI of the Lock-in amplifier is the suitable for my purpose. My purpose is to use labVIEW to plot the hysteresis loop ( relation between Magnetization and applied magnetic field or between the current coming from the power supply and voltage coming from the lock-in amplifier). How can I mix two VIs , one from the lock-in amplifier and another from the power supply. Then, plot the hysteresis loop.

regards,

[GerdW]

Hi Thuriya,

I cannot decide which VI of the Lock-in amplifier is the suitable for my purpose.

Me neither as I can't access those VIs from your image.

I would start with this "Getting Started" VI to learn about the usage of those other VIs!

How can I mix two VIs , one from the lock-in amplifier and another from the power supply. Then, plot the hysteresis loop.

All those basic programming steps are explained in the beginner tutorials.

Have you taken them by now?

[Thuriya82]

Hello,

For BK precision XLN8018, I'm using the attached VI but there is only one value of current. I need to insert Start, End and Increment currents. I need a program where ( For example 😞 The start current = 1 A, End Current = 5A, Current Increment =0.5 and a Dwell (ms) = 1000.

Could you help me?

Also, I attach the VI that I try to do but sill I have an error.

regards,

[GerdW]

Hi Thuriya,

Could you help me?

Sure.

Hints:

- When you want to change a device setting in a loop then you should call the device driver function inside of this loop!

- your comparison logic in the "current" loop looks overly complicated. (Some might say Rube-Goldish or even "wrong"! :D) Why do you need to compare two values after adding 1 to both of them? Why all this "negative logic" like:

IF not(equal) AND NOT(true) THEN continue

Why not just stop on equal==true? Why AND with a FALSE???

Or even better: why not use a FOR loop when you calculate the number of iterations before the loop???

Also, I attach the VI that I try to do but sill I have an error.

Which error do you get?