2400 and 6517 Keithley Sync DAQ

[dalvares]

Hi All, 

I am interested in measuring the frequency response/ switching behavior of some of transistor devices using the 2410 (Gate) and the electrometer 6517A (Source-drain). I would like to hold the source drain at a constant voltage and pulse the gate and vice versa whilst measuring the current also obtaining a time stamp for the data. I understand the pulse width can only be controlled in the 2410 as mentioned in the application note "Generating Current or Voltage Pulses with ‘non-pulse mode’ SourceMeter" . However, since I will be obtaining measurements directly using the onboard buffer I am assuming I would need to use a trigger to sync the recording or the 2410 with the 6517A? Would the trigger need to be external or could I send the read command at the same time to both instruments  

Also I have some sample code that uses low level GPIB vi's to comunicate with the instrument I would like to use NI-visa. What do I put in for the visa resourse name. It doesn't allow me to select it from the drop down list. I know the address of the instrument is 24.. So can I type in GPIB::24::0::INSTR ? The isntrument definately shows up in MAX and I have also been getting static measurements from the instrument. 

:manhappy:

Any comments, suggestion or solutions would be greatly appreciated

Cheers, 

[Albert.Geven]

The first thing to solve is why it does not show up in a VISA resource name.

canyou supply a vi in which it does no show up?

[dalvares]

Hi 

Sure. Attached

[Albert.Geven]

Hi

Why not use the 2400 instrument driver.

The 6517 is a bit more problematic. It is available but not a projectstyle version and not complete.

goto http://www.ni.com/devzone/idnet/  and search for Keithley and 2400 or 6517a

I don't see a problem in you vi except that you are doing a lot of work that is already done better in an instrument driver.

Did you find the instruments in MAX?

[dalvares]

Yea your right. I had the look through the instrument drivers and it seems like their pretty good for doing standard sweeps but I guess for applying pulses Pulses. The code I posted was actually obtained from the keithley forum for doing pretty much what I wanted I guess. The thing I would need to figure out from here how to trigger the using the TLINK. I could also try a SW trigger but I not sure how accurate this would be. The instrument is in another lab so I want to do most of the ground work on the code before I head there.

 Maybe I could use the 2400 sub vi's and directly work from there. Would that be better you think?

[dalvares]

I had a go at writting the code to trigger the 2400 and 6517 keithly just using software trigger for the moment. I was wondering if you could take a look at it for me. 

I have applied a 2 point source voltage. One at 0 volts and the other at 1 volt. I am assuming I would need to control the delay through the source delay time for both source voltages (0,1) and this would define my on and off time. 

For the 2410 I am under the impression that the trigger count is the amount of times the source voltage is applied. So in the case of the 2410 routine is this the number of pulse. How do I improve the data resolution at each pulse. (Dunno if I am asking the correct question)

I have applied a 2 point source voltage. One at 0 volts and the other at 1 volt. I am assuming I would need to control the delay through the source delay time for both source voltages (0,1) and this would define my on and off time. 

Will the output give me a timestamp as well as a current value from both the 2400 and 6517? 
Ideally I want to set the 6517 to acquire continously. Where do I set the sample rate or the amount of samples to ensure I get a good waveform? Is this the trigger count? I have currently set it to INF. 

[Albert.Geven]

Wow, you have a big monitor, I'm getting jealous.

Try to clean up your code by pressing the little broom on the right upper side of the menu bar of the block diagram.

Pressing it more than once does not seem to improve in lv2009. At least your code is better layed out afterwards.

I would not use software triggering but check the driver for hardware triggering. And I don't believe that fast measurements are possible with either instruments but fast is relative. How fast do you want to measure?

[dalvares]

Nice thats a great tip. (2 big monitors actually  )

Yea i know what you mean. I guess for the moment with the software trigger if I could get to something like 20Hz-50Hz that would be good. In the mean time time I will try and find a cable for the hardware trigger link then I can output the trigger from one intrument to the other.