Keithley 2400 Commands

[Mr. John]

Hey guys, I'm trying to figure out how to measure the voltage of my Keithley 2400. I'm using a gpib connection. Does anyone know a simple command for the computer to read whatever voltage the Keithley is currently at?

[smercurio_fc]

Use the drivers.

[Mr. John]

The problem is that I have to create my .vi file by scratch. I can't depend on the drivers or any .vi files that are already made. That's why I need to know if there is a simple command that I can use to read the voltage or current of a keithley.

EDIT: I should also mention I'm using VISA read/write not GPIB read/write. Sorry for the mishap

[Dennis_Knutson]

That seems like a very strange requirement. Does that also mean you can't use any of the VIs that come with LabVIEW? I'm curious why someone would impose such a requirement on you.

Whether you use the driver or not, you can at least download it and look at the code. You should also have the manual for the instrument and finding the correct command is just a matter of reading it.

[Mr. John]

I can use all the VIs that come with LabVIEW, if by coming with LabVIEW you mean things like flat structures, etc. I have the manual for the instrument, it's a Keithley 2400, but I couldn't find any information in it. I also tried looking at the code for a voltage sweep and voltage/current measurement of the Keithley that I found online. However, I literally just started even learning what LabVIEW is, so I couldn't really find what command they used to read the current/voltage of the machine =(. Does anyone have any ideas on what these commands may be?

[smercurio_fc]

That still doesn't explain why you can't use a driver. Is this for learning?

There are 3 commands for getting data from the instrument: FETCh?, READ?, and MEAS? The difference between the commands has to do with whether or not they re-configure the measurement or rely on the measurement being already configured. Chapter 17 of the user manual discusses these.

[Mr. John]

smercuio_fc: This is a mixture of learning, and a mixture of getting it all done =). Ah, and it turns out the entire time I was looking at the Quick Results Guide instead of the actual User's Manual. Lemme see if :FETCh? command is what I need!

[Dennis_Knutson]

You aren't reading the correct manual or reading it closely enough. Page 17-2 lists the FETCH, READ, and MEASURE commands.

Is this a test to see if you can actually write a progam as opposed to a test that needs the instrument. I can't see any other reason to make a new LabVIEW programmer reinvent the wheel.

In any case, before you do anything else, make sure you check the free LabVIEW tutorials and study the Instrument Control Fundamentals.I would also doing a search for 'SCPI' to understand the generic programming language framework of the instrument.

You may have to reinvent the wheel but getting help here will work better if you at least understand the fundamentals.

[Mr. John]

Dennis: I was reading the wrong manual =P It was the quick guide instead. Also I did a majority of the tutorials, so I have a basic grasp of LabVIEW. I'm now going through this actual manual and I'll see if I can get some results. I don't have time left to go through any more tutorials however because of my deadline.

[Dennis_Knutson]

So you plan on posting a lot of questions here instead of learning it for yourself? Not sure that is the way to get help. People here are volunteers and are much more inclined to help someone who has code that needs fixing instead of providing entire solutions. Just something to keep in mind. I would also be inclined to simply post code from the driver if you ask for additional help with commands.