keithley 4687 GPIB

[pinim]

Hi community,
I would like to consult with you about LabVIEW monitoring and control for Keithley 6487 picoampermeter / voltage source.
I am applying voltage and reading a current measurements, presented on a graph.
I would like to know how can I limit the measured current to 100nA and make the software to shut down the instrument through VISA.
Also I would like to know how can i save the current data for later data analysis.

Thank for your help.
I've attached the basic virtual interface that I built.
Pini Medved.

[elcalverado]

Pini,

I haven't used this instrument, but I've been looking through the manual for it at this link:

http://www.testequity.com/documents/pdf/keithley/manuals/6485-6487-m.pdf

All of my answers are solely based off what I found in the manual rather than actually having tried this.

It looks like you have a few different questions. Let's break them down:

1.  How can I limit the measured current to 100 nA?

Check out page 65 of the manual. It gives an example of the SCPI commands that need to be sent to perform a current measurement, including setting the current limit and telling the instrument to read one sample.

2.  How can I shutdown the instrument through VISA?

Looking through the manual, it seems that there is no way to programmatically turn off the instrument, as far as I can see. You have to manually push the power button.

3.  How can I save the data to disk for later analysis?

There are many methods of saving data. After all of your data is collected, you can write the data to a delimited spreadsheet file, a txt file, or a TDMS file. There are many shipping examples in LabVIEW that show how to save data to a file.

Sincerely,

Jordan

[GerdW]

Hi pinim,

make the software to shut down the instrument through VISA.

When this Keithley is a "voltage source" you most likely can turn off it's output. Even when this is not implemented, which I doubt, you can set the voltage to zero…

Again: the commands to do so are found in the manual of the device!