09-28-2018 11:17 AM
Hello,
I use the device Keithley 6517A as a voltage supply and as a current reading.
I use the vi "V-Source Output.vi" to select the voltage value in output (-1000 V to +1000 V) and after, I do a reading current.
Before doing my current reading, I would like to check that the output voltage is correct. Does anyone know if it is possible to know this output voltage?
Thank you.
Solved! Go to Solution.
09-28-2018 11:55 AM
The Model 6517A can make unguarded or guarded voltage
measurements from 1µV to 210V. Guard should be used if response time or leakage resistance is a consideration. The concepts of guarding are discussed in paragraphs 2.4.4 and 2.5.3
I attached
I can attach the very old manual, but maybe a driver exists.
You have to specify the measurement and then read the value.
I checked and found a driver at NI. please search the correct driver within the site.
search support select drivers select instrument drivers type Keithley 6517
and select the version you need
An acquire measurement.vi delivers what you need.
09-28-2018 02:13 PM
The 6517a is an electrometer (or a very sensitive DMM) that also just happens to have a built in voltage source. You can use it to measure current, voltage or resistance.
But unlike an SMU (source and measure unit) an electrometer can't measure voltage sourced and current at the same time. The voltage supply is a separate set of terminals. You can connect the output voltage source HI through your DUT (load) to the input terminal to create a "force voltage source current measurement" which is used for very high resistance test. But this configuration does not enable voltage sensing, only current sensing. If you are trying to measure high resistance you assume the voltage drop occurs all across your load and that R=V/i applies. Now, ideal pure resistance loads don't really exist, if you have any capacitance in your device then Vactual is not going to be the Vsupply instantaneously. You should give the measurement some settling time, and the electrometer can be configured to take reading for as long as required to get a stable current.
What are you trying to measure? Do you suspect V is not correct? You can have the output calibrated if you don't think its right, you could do measurements of current in your DUT as a function of time and see if there's noticeable charging. If that's true then you might want to revisit your measurement technique; higher voltage, longer settling time, etc...
10-01-2018 03:25 AM
Thank you for your answers.
I use the 6517a in a physic experiment. With the voltage source, I polarize a cup of Faraday, and then do a reading of current.
I start with a voltage of -300V and I end with a voltage of +300V. For each voltage, I am doing a current reading.
I know that if I ask the 6517a to release a voltage, it will do so but it requires a certain delay.
In my labview program, I do :
1) give a voltage output order
2) wait a short time
3) read a current
Il like to add a reading of the voltage output before to read the current.
I don't know if the 6517A has a labview vi that give the voltage source.
10-01-2018 03:11 PM - edited 10-01-2018 03:23 PM
Edit: I provided a bad link.
Perhaps you want to have a look at using the sweep function.. https://forums.ni.com/t5/LabVIEW/Keithley-6517B-Current-vs-Voltage-Plot/m-p/3816727/highlight/true#M...
It appears you can get the voltage source value (not a measurement of Voltage, just the Voltage Source's set point), but you need to reformat the data string elements being sent by the :READ?. See sections 3-75 and 3-77. https://www.tek.com/manual/model-6517a-electrometer-users-manual-rev-d-manual
Craig
10-02-2018 11:11 AM
Thank you very much.
06-12-2023 09:25 AM - edited 06-12-2023 09:43 AM
For people who may stumble on this thread: be careful with the NI drivers, there are some incompatibilities in the implementation:
Example for pretriggering: the :AMO:PERCent and :AMO:READings commands are mutually exclusive... one cancels the other, so the pretrigger setup VI in the driver (diag below) doesn't work correctly