PCI-4070 measurement of Voltage and Current at the same time

[NewFifty]

HI all,

Now I wanna  measure the voltage and current in my target circuit from my LabVIEW procedure. But  I find that all the examples are focus on the measurement of only voltage or current. And the functions of NiDMM only support one measurement at one time(by given function input number).

So,

1) Any method for measuring the voltage and current at the same time from LabVIEW on PCI4070?

2) Does the PCI-4070 support the two-channel measure at the same time?

PS. The requirements do not support the delay for the measurement of voltage and current (we also need calculated results based on the measurement), so the sequential mode is not supported.

Thanks~

[crossrulz]

The DMM can only measure 1 thing at a time.  Sounds like you should be using a DAQ with some signal conditioning (current sense resistor, amplifier, op amps).  Or you could use a second DMM.

[NewFifty]

Thanks, Can i use the occurrences fucntions to divide each measure to different CUP and do the measurement?....

But the issues  are also here for only measuring voltage or current one time!

[crossrulz]

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@NewFifty wrote:

Thanks, Can i use the occurrences fucntions to divide each measure to different CUP and do the measurement?....

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I have no idea what you are trying to say here.  The limitation is the DMM.  You could have a second DMM and have a trigger mechanism so they measure at the same time.  If it were me, I would go with the DAQ.

[kirsch]

Multimeters are designed to perform one measurement at a time. NI Multimeters have 1 channel.

If you want to measure both current and voltage at the same time, the appropriate instrument to use is a Power Supply / Source Measure Unit.

[NewFifty]

Thanks. Now I have several NI USB-6009 on hand, so  can I use them to measure the current? Sorry I am totally a new user for NI products. So if it is available, are there any advice and examples to use the 6009 for measurement?

[crossrulz · Accepted solution]

In LabVIEW, go to Help->Find Examples.  There are plenty of DAQmx examples in there.

For measuring the current, I would recommend using a 0.01 Ohm resistor and a current sense amplifier such as a TSC888C.  This would give you a direct voltage to current relationship (TSC888C has a gain of 100, multiplied by the 0.01 Ohms and you get an output voltage equals the current, but a maximum of 1A).