Keithley 2460 LabVIEW code for Voltage-Current plot showing error

[reshnaelsaphilip]

Dear all,

I am using Keithley-2460 for source voltage sweep and measure current. I wanted to get the voltage versus current plot for a resistor. I have modified an example code for getting sweep voltage and current waveforms. This one was for keithley-2450. I have installed 2450 instrument driver since it was suggested okay to be used for 2460. I am using a two wired connection and I am getting an error of "No readings exist within buffer" for both example code and modified code. I have tried different ways and could not solve it. Keithley is showing V-I plot correctly in its monitor without LabVIEW code. Can someone please help me in solving this. I am attaching both codes, the videos of running the code and images of set up ( can be seen from the google drive link). Thanks in advance...

Reshna.

[cstorey]

I'd suggest you run the code in Highlight Execution, pausing after every subvi to see what the errors are.  You might only be seing the last error in the chain, and there might be many more that are cleared along the way.

Make sure that the compliance value is set high enough.  In the attached its only 0.1 V or A.   Depending on what you choose as source it will be opposite.

Next look at the timeout value hardcoded in the example which is 100000ms, or 100s.  If your measurement is taking longer than that then the buffer might not contain any data to read back.  If you set a large NPLC then you need to set a long timeout.

Hope that helps.

Craig

[reshnaelsaphilip]

Thank you so much for the reply Craig...I have tried changing the compliance level to 5.1 maximum which was set to 0.1 initially. I am  sourcing voltage and measuring current across 200 ohm resistor, maximum voltage will go only up to 10 V so the max current level will be 0.05 A, ie why I set 0.1 A.  Also the waiting time for operation was changed to 1000000 ms and the waiting time inside stacked sequence was also increased 20000 ms, but I was again getting the same error. I have run the code in highlight execution, I could only see the error coming at read multiple points sub vi. I am attaching the image of front panel and the video while running the code. Please check it.

I have also tried once by adding a sub vi " Make reading and store in buffer" before read multiple points, but could not succeed. Can there be any other possible reason for this "No readings exist within buffer " error..