Measuring AC voltage with NI 9219

[don_Micheal]

Hi everyone!

Is it possible to measure AC voltage/current with NI 9219 in voltage/current mode?

If not, what NI module I should use to measure AC voltage/current?

Thank you so much!

[GiantDeathRobot]

Hey Don,

Just FYI, you might get better suggestions on the DAQ capabilities over in the Multifunction DAQ community. You're limiting your audience to people who use the NI 9219 in cRIOs over here.

Whether or not you can measure AC voltage/current entirely depends on the voltage/current you're trying to measure. What are the voltage/current ranges you're after?

[MarkCG]

I wouldn't use a 9219 because voltage range and sampling rate is too low for 60Hz mains power. It's just not designed for that. Check out the NI 9225, NI 9242 and NI 9244 instead

[don_Micheal]

In fact I want to measure the current through an AC servo motor using a Hall effect sensor. The sensor output is the voltage across the motor which is proportional to the current through it. The motor is supplied by the 60Hz electric power.

[don_Micheal]

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@MarkCG wrote:

I wouldn't use a 9219 because voltage range and sampling rate is too low for 60Hz mains power. It's just not designed for that. Check out the NI 9225, NI 9242 and NI 9244 instead

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Is it possible to use NI 9239 for that measurement?

[MarkCG]

it's all dependent on how you sensor work. You mentioned a hall effect sensor, so what does its data sheet say it puts out?? Does it give you a root mean square current or just the instantaneous current ? post a link to the sensor

[don_Micheal]

I used the following sensor: https://www.allegromicro.com/en/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-S...

I think it gives me the instantaneous current.

[MarkCG]

yes  I think the 9239 would work for well measuring the IC's output. You can sample fast enough with that module to capture the AC frequency. Since it's a ratiometric output you could also sample the supply votlage to the IC for increased accuracy

[don_Micheal]

I decided to use  NI 9239 module. It seems to work well. Thank you so much for all your help!