MOSFET IV curve

[bhuyanashima]

I want to apply vd and vs simultaneously through Keysight B2901B and apply DC bias Vg through Hioki IM3536 and then get an Id current. I want to be able to display Id-Vgs or Id-Vds on front panel and save it as csv file. please help with the code I am a beginner student.

[GerdW]

Hi bhuyanashima,

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@bhuyanashima wrote:

I want to apply vd and vs simultaneously through Keysight B2901B and apply DC bias Vg through Hioki IM3536 and then get an Id current.

I want to be able to display Id-Vgs or Id-Vds on front panel and save it as csv file. 

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What have you tried to achieve all the stuff you "want to"?

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@bhuyanashima wrote:

please help with the code I am a beginner student.

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Sure: what have you tried so far?

Mind to show your current code?

Where are you stuck?

[bhuyanashima]

I don't seem to be getting a measurement even after applying 3 for loops separately for Vg, Vd and Vs.

 

[altenbach]

We cannot debug a photograph of a diagram, but we can tell that you code has no recognizable architecture, not even a toplevel loop!

There is a circular dependency where LabVIEW falsely auto-inserted a feedback node, eliminating a broken wire, but creating useless code. (Your shift register is initialized before the loop with an array where the size depends on values that are only available after the loop has completed. Makes no sense! Have you really thought this through????)

Attach your VI, make sure all controls have reasonable default values, an explain exactly how you use it, what you observe, and what you like to see instead.

[Basjong53]

Based on the code you showed, I suggest to take a step back and break the problem into small chunks, because it seems that you wanted to solve the entire task at once, without understanding the individual problems.

Start with the most basic. Manually set a voltage on your Hioki (without programming). Then make a program just to apply a voltage ramp on your Keysight and plot Id vs Vd. Make use of subVIs for all Keysight calls (generally you don't want to see any device specific code on the main VI, it should be in subVIs, preferably part of a library (or class). Also make sure that no wires run right-to-left! It will give you a much more organized code.

Once you solve that, add the code for the Hioki. Again, in subVIs (part of a library or class). Test the code individually before applying it to the main program.

Solve the problem step-by-step and you'll get there.

P.S.

A MOSFET has 3 contacts. You should apply 2 voltages (not 3): Vg and Vd (both references to Vs)

[bhuyanashima]

when i run the code, nothing shows up on the xy plot. i want Id-Vg curve or Id-Vd curve to show up on the curve

[GerdW]

Hi bhuyanashima,

when you want more help with your VI I recommend to provide a downconverted version (File->Save for Previous).

Most recommend "LV2021 or older", I prefer LV2019…

[bhuyanashima]

this one?

[GerdW]

Hi bhuyanashima,

thanks for downconversion.

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@bhuyanashima wrote:

when i run the code, nothing shows up on the xy plot. 

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Because you did NOT follow any of the given advice/comments!

• Please cleanup that block diagram as suggested.
• Remove the (automatically inserted) feedback nodes.
• Start with a simple outer loop instead of using the RunContinuously button…
• Stacking 3 FOR loops doesn't look right, there most often are better code architectures!
• Why do you need to convert arrays to higher dimensions (from 1D to 2D, from 2D to 3D)???
• Why do you branch VISA reference wires and try to communicate with ONE device in parallel??? Communication with one device should happen serially…
• What's the point of ORing with FALSE?
• Why do you create the ramp inside the loop even though the ramp parameters CANNOT change inside the loop? Do that once before the loop!
• Do you know the difference/meaning of all the different tunnel modes? (Did you do any of the basic training courses offered at the top of the LabVIEW board?)
• lot's more stuff…

[bhuyanashima]

hello i am back with a new code for the same problem. also we are intending to use RIGOL for DC biasing. we are getting the problem of OCP tripping. how do we solve it?