Multifunction DAQ

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Level meter sensor to DAQ

Hi Everyone,


I have a level meter sensor LVCN 414 that I want to connect with PCIe 6323 through SCB-64A.  

Could someone please help with wiring the levelmeter to DAQ? I tried several times but it didn't show the correct signal in whether NIMax Test Panel or LabView. Here attached the wiring configuration that I want to follow.





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The sensor you want to use has a current output (4mA to 20mA)  proportional to the level.

Read the spec and connection diagram of the SCB-64A, section current input.

You need an external 24V power supply and a current sense resistor.

I would use two 470 Ohm (quite common value ;))  resistors in parallel giving 235 Ohm, resulting in 4.7V @ 20mA.

Configure to 0 to 5V range (differential if possible) and apply the current sense resistor over the two (+ and-) inputs of the SCB-64 and power as noted in your posted schematic.



While you can use a 400 Ohm (max value) resistor and the 10V range , the current will flow and heat the resistor, so smaller values (or/and a better resistor with a lower temperature coefficient) is prefered.

Greetings from Germany

LV since v3.1

“ground” is a convenient fantasy

'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

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Hi Henrik,


Thank you for your reply. I connect the system with 12 V battery, I think it should be enough because the range is from 10 to 24 V. I make sure that my battery has power above 11 V by testing it with a multimeter. I use 100 Ohm resistor and I connect to AI0+ and AI0-. But NIMax and LabView cannot detect the signal. I asked in a different topic about my SCB-68A connection and PCIe 6323, and then I tried the solution to first check with Loopback test and the result is not correct. Moreover, I tested to connect a 1.5 V battery and the result was not correct as well. Is my device broken? But the result from DAQ diagnostic tool as good, the PCIe was able to pass all the tests. FYI, this is my department's device so several people used it before me and they have to move this device from one city to another. 


Thank you.



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Are there other analog inputs on the card you can try out?



"It’s the questions that drive us.”
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I tried every AI port in my SCB-64A.



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