Sourcing current with Keithley 2450 and measuring voltage using NI 9239 DAQ

[weazidaki]

Hello guys, I am fairly new to LabVIEW and I am trying to write a LabView code where I have a Keithley 2450 that only sources current, and a NI 9239 DAQ will measure the voltage. The current problem I have is that I cannot find a way to do so. I have tried the code where the Keithley sources the current and measures it however the NI 9239 DAQ is unable to measure the voltage. Is there a better way to write the code in order to get my desired outcome? I have attached a picture of the code I am working on. I've tested the code and the Keithley device is able to act as a current source and measure it however the NI DAQ is unable to measure the voltage. Is there a way to just make the Keithley device Source the current repeatedly?

[GerdW]

Hi weazidaki,

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@weazidaki wrote:

1. however the NI 9239 DAQ is unable to measure the voltage.
2. I have attached a picture of the code I am working on.
3. I've tested the code and the Keithley device is able to act as a current source and measure it however the NI DAQ is unable to measure the voltage.

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1. Why is the DAQ device unable to measure a voltage?
2. We cannot run/edit/debug images with LabVIEW...
3. Again: what's the reason?

Have you tried to measure a known voltage, like from a simple AA battery, to verify the cabling?

[weazidaki]

Thanks for the quick reply,

The current testing configuration has the force hi and force low cables connected to two ends of a 1k ohm resistor. The ai0+ and ai0- lines are connected to the inner portion of the ends of the resistor. I disconnected the Keithley device ad the NI DAQ was able to measure the voltage. However, when I reconnected the Keithley device and tried to run both of the devices at the same time, the NI DAQ showed random data. I uploaded the VI file that I am working on, sorry for not uploading it in the first place.

[GerdW]

Hi weazidaki,

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@weazidaki wrote:

The current testing configuration has the force hi and force low cables connected to two ends of a 1k ohm resistor. The ai0+ and ai0- lines are connected to the inner portion of the ends of the resistor. I disconnected the Keithley device ad the NI DAQ was able to measure the voltage. However, when I reconnected the Keithley device and tried to run both of the devices at the same time, the NI DAQ showed random data.

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Can you please attach a schematic of your cabling including both DAQ devices and the resistor?

What are "force" cables?

Which kind of "random" data?