I-V measurement

[Eliotwmh]

Hello all,

The attachmet is a IV measurement labview program with Keithley 26XX series. Below is the program that I do. However, the delay time is much more than what I set in the front diagram, I would like to fasten the system. Please advise.

Thx

[Henrik_Volkers]

To make such measurements you should use the internal hardware timing of the Keithley and fetch the data.

Seems that you have the manual for 2600, so  it's time for some more RTFM 😉

And take a look at the instrument driver section

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=8076

[Eliotwmh]

Hey, Thanks for your suggestion, I have read some of the examples but I still confuse with the solution of fastening the measurement. Would you mind giving me some more hints or advice? I am quite new to labview.

[pjr1121]

I recently wrote a program using a Keithley 2440 for I-V measurements via GPIB.  Based on the images you provided, it looks like you use labview to set the voltage, then read the current, then repeat.  This increases the amount of time your measurement takes because you have to wait for the communication between the device and the computer between each voltage value and then your specified delay time is executed.

For the 2440, I utilize the linear sweep option of the source meter to set 100 voltage values evenly spaced between specified max/min values, either selected by the user on the front panel or calculated as a scalar multiple of Voc (this is to prevent going outside a safe range of current values, thereby damaging the solar cell).

After this, it is necessary to check the service request bit as a means of waiting until the sweep is finished.  This is done by (for the 2440, not sure if it's slightly different for the 26xx series) setting the following bits.  BFL (buffer full) of the Measurement Event Enable Register and MSB (measurement summary bit) of the Service Request Enable Register.  Upon buffer full, the RQS bit of the Status byte register will be set.

Use a while loop to periodically send *SRE? (once again, not sure if this command is different for you) to check this bit of the status byte register.  Once this is set, read the values stored in the buffer (I chose to fill the buffer with the voltage and current values).  The measured values will be returned in a spreadsheet string (comma separated in the case of the 2440).  After this, it's simply a matter of placing the voltage and current values into arrays.

In my experience, Keithley offers superb documentation for their devices.  Using the information above, and the 26xx series user's manual, you should be able to get your system up to speed rather quickly.

[560092]

Were you able to use 26xx for IV measurement. I want to source current pluse e.g 100 mA for 50 ms and 0 for next 150 ms. Can you please help me regarding this. Were you ablse to fix the timer problem?

[GerdW]

Hi 560092,

did you read the manual for the Keithley2600?

Does this SMU allow such current pulses?

If it does: what settings are required?

Did you read the description of the SCPI-commands needed for setting up the pulses?

Did you try to write a VI to output those commands to the device?

What have you done so far?

[560092]

Hi, I am currently sending voltage pulse and recording I vs Time using 2611 and labview. Attaching the VI. Earlier more than a year back I was using PXI 6221 and then I tried to send pulse using DAQ  and amplify before feeding to device, and faced time problem with finally generated signal. Now I want to source current pulse from 2611. It can allow the required range of current I have mentioned in my earlier post. Not sure which command you are talking about for pulse.

[GerdW]

Hi number,

the 2611 might be able to source 100mA as you required - but does it allow short pulses?

If it does allow pulses: how do you configure them?

Did you read the SMUs manual? What does the manual write about configuring pulses? Here you will find all the commands possible for your SMU and all their parameters/options! As it's your task to configure your SMU I don't want to look up that information for you...

But I guess it's all in the manual...

[yogesh5387]

Can you please upload the vi file for Keithley 2611A for measuring Voltage and current that could be very useful  for me...

Thanks in advance...!

[yogesh5387]

Can you pleaae upload vi file for V-I for kiethley 2611A ...

Thanks in advance.!