data collection with keithley 2400 and lv6

[szhil]

    Im a student working with a Keithley 2400 and lab view 6.  Im doing a voltage sweep using a VI I downloaded off Keithley's site (2400swp(vxi)).  The instrument is controlled correctly and the instruments buffer contains the correct values, but the readout on the front panel is garbage.
    Im assuming that the subvi KE24xx Read Buffer returns a pointer to the array and that pointer is displayed instead of  the actual value.   How do I fix this code without having to rewrite the Read Buffer VI?
    If my assumption about the array pointer is correct, I would appreciate a link to a tutorial on arrays in LV or a solution.  If you see something else thats wrong, point it out please.
    Once again I stepped through up to Read Buffer and am certian the hardware has the correct values at that point, just the PC screen and the hardware screen dont sync after that point.  The VI is attached.

[Dennis_Knutson]

Your assumption is not correct. The VI should be returning the actual values. Unfortunately, the VI is a VXIpnp driver and that means it was converted from a LabWindows/CVI written driver. The VIs you see are just wrappers around a call library function node that calls the dll created from the CVI 'C' source code. It would seem that there is some sort of bug in the way the code reads the values from the meter and converts them to SGLs. Unless you have the CVI source code and LabWindows, I don't know how you can fix the driver. What you might be able to do is write your own function in LabVIEW that reads the instrument buffer and use that instead of the provided one. I think the library has a KE2400 Write Instrument Data and Read Instrument Data that you can use to send commands and get the results. I looked at Keithley's web site and I saw that there is also an IVI driver. You could try that as well. You could also try contacting Keithley and letting them know the problem. You should include informations such as the actual values you are seeing in the result array and what the instrument buffer actually has.

[szhil]

Thanks for the info, I spoke with the person that wrote the code at Keithley and apparently the code executes on his machine.  The difference between us is Im using a GPIB-USB-HS and hes using an older card.  Im going to re-write the read buffer code but Ill check out the other driver first.