Simple Threshold test using Keithley 2000 and 2430

[araneve]

Hello,

I am just learning instrument control via Labview and decided to dive in a test to jumpstart it.

I was able to connect our Keithley 2000 DMM and 2430 Sourcemeter and run the labview examples successfully.

Now I wanted to ask for some advice and direction in making a threshold test for a supply monitor device.  I would generate the ramp using the 2430 on the input/sense pin and  monitor the reset pin using the 2000.  My first attempt, I increment the sourcemeter a few millivolts at a time then stop when the DMM detects the reset is active.  However, this proved to be so slow, especially when I want more resolution determining the thresholds.

So I plan to use the 2430 sweep generating function.  But I foresee a problem in trying to sync both instruments.  Can anyone suggest a better way to implement this? Then I will try to build my code and post it here for further comments and suggestions.

Thanks in advance...

[Albert.Geven]

depending on your device?

is the circuit designed to survive a too high current?

Or can you use the timing in the 2400 sweep to stop when a digital input "aborts" the sweep.

I know that you can link keithley instruments via the digital IO pins but the keithley 2000 stays slow.

[araneve]

Thanks Albert.  This is for testing 3-pin microcontroller supply supervisors like IMP809 or MAX803.  I will be using no load to simplify things and force voltage only to Vcc. So I don't really need to abort the sweep.  But trying to mark the threshold point on the sweep is kind of tricky (at least for me)

By via digital I/O, you mean the trigger link? I'll try to find a cable for that one and check if it will bring a much quicker result.  But since I will be doing the trigger setting through Labview, I also think that it will not be as fast.

Once I got the equipment back, I will try to use the sequencing frame to make sure the sweep and the Keithley 2000 measure loop will run at the same time. I hope the program will be able to tag the threshold point. Maybe this will take care of the timing. Looks like its not as simple as I hoped it to be.

I'm not sure if this is the right way to do it but learning is all about trying things out.  I wonder if there is any other way to do it.  Its good to learn the hard way.

[Albert.Geven]

Hi

With timing I mean NO sequence frames!

Sequence frames are not the best way to sequence things in LabVIEW.

Normally the error in-error out is used to have sequencing by wire. It is much batter readable and also gives you an idea where it went wrong.

[Josh_L1]

Hi araneve,

Synchronization is usually done at hardware level in cases where you need precise triggering. I would strongly recommend contacting Keithley about it. I've also included a few of general articles on synchronization below for your reference.

Synchronization How-to

http://zone.ni.com/devzone/cda/tut/p/id/9754

Synchronization Basics

http://zone.ni.com/devzone/cda/tut/p/id/9652

Timing and Synchronization in NI LabVIEW

http://zone.ni.com/devzone/cda/tut/p/id/11466

I hope this helps.

Josh L.

[araneve]

Wow, great stuff! Thanks Josh, that is a good read and will try to figure it out in the block diagram.

Thanks too, Albert.  Believe it or not, I also did try this before I made the thread and found how silly of me to use the compare function without understanding the data type I should use.

Greatly appreciate the help.  I'll start to code and try things you guys suggested.

Best regards