6221-2182A to plot IV of FET

[HamzaZG]

My Professor has asked me to make a program to measure the IV of a FET using 6221 (to source/sweep current) and 2182A (to measure voltage). We are using these instruments as the device is made of very delicate material and can support current under 100nA range which means that the voltage across device will be very very low (hence using 2182A Nanovoltmeter to measure the voltage) .. 

After measurement I want to plot IV.

I can program the 6221 to sweep but I can not get the 2182A to measure voltage as the sweep progress. The problem is I can not get the triggering to work. (I am using GPIB card for connectivity between the equipments not RS-232 cable). Also I am not using delta, pulse delta or conductance mode. I need the 6221 to source and send out trigger and the 2182A to take measurement and send back a trigger which will change source level of 6221. 

Does anyone know how I can accomplish this ... Source 6221 .. Measure 2182A .. Plot IV after measurement.

A more general question is which instrument buffer will save my result. I mean will the 2182A have my measurement only or will it have source level and measurement or will the 6221??

Any help will be appreciated .. 

Thanks

[Albert.Geven]

Just do it in software:

Set the source in the smu, read the voltage from the nanovoltmeter and do the next step.

Nothing is kept in one of the instruments you have to read out both!

[HamzaZG]

Albert .. Thank you for your help ..

I can now source the current sweep from 6221 and the nanovoltmeter is measuring the voltage across my device .. But I have one problem .. I can not get the buffer to work on both devices .. When I perform a sweep through labview I can see the change in source and reading on the front panel of the instrument but when I check the buffer, the buffer of both instrument comes out as empty ..

I have attached my VI with this post .. It is still a work underprocess and needs alot of improvement. 

[Albert.Geven · Accepted solution]

I agree, a lot of improvements are making your program better.

First of all, why are you not using the instrumentdrivers available for these instruments.

These drivers are not perfect but help you to focus on your real problem.

And another remark, just to begin with. If you have wires connected between vi's you don't need a sequence frame anymore.

This is called sequencing by wiring and is much less disturbing than sequence frames.

And it already works...

[HamzaZG]

I tried using the VI/program provided by Keithley but I can't get them to work .. I am using GPIB to connect both  device to my computer but the 6221 always gives me error that it did not detect the 2182A nanovoltmeter (as nanovoltmeter is configured to work on RS-232 cable with 6221) .. I have not yet been able to get around this problem

Thanks for the squence frame suggestion .. It makes my program look simpler and must less congested ..

Buffer configured and enabled but now the problem is reading data from buffer .. 2182A

[Albert.Geven]

Hi
When the nanovoltmeter is configured to have rs232 as the interface you should reconfigure it via its hardware front panel.
See the manual how to do that.

[SiddharthK]

Can you please provide the drivers of Keithley 6221 and 2182A for NI-LabView version 8.5. I tried many drivers from various sources for the same two devices but they are not working for my current version of LabView.

Keithley has provided a program for various measurements through the instruments which works perfectly but I can't save the data through that, and it is not editable. 

I'm also doing same project of measuring IV using 6221 and 2182A, where the two instruments are connected by each other using a RS-232 cable and 6221 is connected to PC via GPIB cable. Here also I'm unable to communicate to the voltmetre(2182A). Please tell the solution if possible.

Thank you.