No data from Keithley in my program (but they are in the display)

[lacorgui]

Hello labviewers,

I really need your help. I have a keithley and I´m using an official example from Keithley company just for sweeping V and measure I. However, when I run the program it runs without errors but I don´t get any V or I (this sweep is made in the instrument since I see the sweep in the display, but no data return to my program). 

If I put some "probes" in the multiple point output (that is voltage and current measurements), I don´t receive numbers, just [].

Does anyone any idea what I must do?

(I´ve been using Keithley drivers since it is easier for me than start with VISA programming, was that my first problem?)

[lacorgui]

I posted this issue in one of my old post (http://forums.ni.com/t5/LabVIEW/sweep-voltage-keithley-2400/m-p/3053669#M869925) but I close the other one, sorry for the apologies. 

Any help is welcome

[Norbert_B]

Don't the Keithley instrument driver include examples? If so, try if they work.

Since i (obviously) don't have that driver installed, i cannot look into the palette. But i wonder if there is some kind of "Start" or "Enable Input" VI available.

Does the instrument create the sweep at all?

Norbert

[lacorgui]

Hi Norbert, 

in fact the file i attached is one of this examples but I can not receive any data. The enable input is set to true. The strange thing is that I´ve been using it the last two months and it worked and suddenly two weeks ago it stop working. As I said, the keithley receive my orders and it makes the sweep because I can see it on the display. Also, there is no errors in the program, just that where I should have current and voltage I got nothing. 

(I´ve run the program in other computers and it works, but it does not work in mine, not idea why).

[lacorgui]

Nowadays I´m trying to do the same sweep using fundamental VISA programming but I don´t get any results (it´s my first time "using" VISAs).

[Dennis_Knutson]

The driver uses VISA so you've been using it all along.

Since the example works on another pc, you have s problem with your pc, assuming you are using the same instrument. If you are using different instruments, run the same program with the same instrument.

You can enable I/O Trace on both pc's to see if there is a difference. On the failing pc, you can also do a quick communication test in MAX by doing an id query. It would also help if you provided the type of physical connection.

[lacorgui]

Hi Dennis_Knutson,

my connection is a KUSB_488a (I´ll try what you comment, but MAX gives me an "unexpected error" and it gets closed before I can even use it). 

The strange thing is that other programs (like the one attached), work. My problem is my lack of knowledge in Labview. It was "easy" to make my own program using Keithley drivers (a similar program to the first Keithley example attached) and it worked until two weeks ago. However, I´m not able to communicate using VISA (and as someone said before: reinvent the wheel)

I´ll keep fighting!

[Dennis_Knutson]

There is something corrupt with your installation of MAX. I'm not sure what special steps you need to take in order for the Keithley GPIB controller to work with MAX and LabVIEW but I would review the instructions you got from Keithley. For a Keysight/Agilent, you install the vendor's low level GPIB driver, their VISA, and NI-VISA as primary. Then tulip support for NI-VISA is enabled in MAX.

[lacorgui]

Thanks Dennis_Knutson, I´ll check it!