Hi all,
I am trying to initialize a measurement on the Keithley 2636A SMU, so that the measurement is done by the instrument and data points stored in the instrument SMU buffer. I only want to use LabView to download the data trace (i.e. multiple measurements saved in the SMU buffer) via GPIB cable to my computer once the measurement is complete.
I want the instrument to carry out the measurements (continuous sampling), instead of triggering for single measurements through LabView. This way, speed, sampling rate, and # of total measurements of my experiment are not limited by how fast the LabView trigger loop is run, or the buffer size of LabView/GPIB.
With this process flow: 1. initialize instrument and measurement parameters, 2. initialize buffer to store multiple measured data points (e.g. 100 measurements) 3. open SMU output, 4. trigger instrument to carry out the multiple measurements (100 samples) 5. print the buffer data range out to an excel file on the computer, this is the code that I wrote (at end of this note).
After some troubleshooting on my end, I realize that there is no issue initializing the SMU & measurement (first half of code doing that is fine), but when I use the BUFFER VIs in the Keithley instrument driver lib, I get an error. I was running into errors using the CONFIG BUFFER MODE VI (which is why I am not using that VI anymore in the code). Instead I use the "CREATE READING BUFFER" VI to create a buffer of size 100. And then use "CONFIG READING BUFFER DATA CHARACTERISTICS" to define my buffer.
This is the error I receive:
(Error -1074000000)
I am not sure if this is because I am not using the BUFFER VIs incorrectly, or if the trigger VI I use to call and initiate measurements is not doing any measurements (hence, the "empty buffer"). How do I call a trigger VI so that the instrument knows how many samples to store in the buffer before stopping measurement?
Please do share if you all have any thoughts on this! Whether I am using the buffer VIs incorrectly or the trigger VI is not filling up the buffer like I think?
Thanks a lot!
Snippet of trigger VI and buffer initialization. Complete VI attached.
(P.S.) The issue is not that I am not allowing enough time for the measurement after triggering (and before calling the Print Buffer VI. I tried putting a 2 minute delay there, but that does not help