need help to connect sensor with NI-6009

[sher786]

hello all, i need some help to conect my load cell and displacement sensor with NI-6009, i want to connect both sensor with DAQ device and want to get data. i dont know too much of labview or data aqusition system, basially i am agricultural engineer thats why i have not too much knowledge about these, now i have tried many times to connect sensors but failed, i have watched some videos as well, but did not succeded, please let me know about these, i am attaching the photos of sensors and NI-6009.

thanks in advance

[Bob_Schor]

The USB-6009 has Analog Input channels (±10v), Analog Output channels, and Digital I/O channels (TTL).  The pictures you show are very interesting -- almost as helpful of pictures of LabVIEW Front Panels or pieces of Block Diagrams (hint -- don't even dream of submitting a picture of your LabVIEW code -- attach the actual VIs, with as much supporting documentation as you can).

What are those things?  What are their specifications (attach the manuals!)?  Are they Analog, Digital, or what?  Do they need power?  Do you have power?  [The USB-6009 won't "power" the sensor -- it only has a few ma of drive].

Bob Schor

[irPaul]

Welcome to LabVIEW!

There's two things that you need to get sorted in order to see the sensor data.

1) Program LabVIEW to read the analog input from the USB-6009 device. For this, check some of the DAQmx examples that are shipped with LabVIEW: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000004B6mSAE&l=nl-NL

2) Connect the sensor to your USB-6009. For that you (we) need to know the specifications of the sensor. The picture does not show manufacturer & type. What you need at least is the output specifications and whether it needs power supplied to it.

Furthermore, what is the other piece of hardware? Should that also be connected or actuated?

[sher786]

thanks for you kind response dear sir, i have one displacement trasducer with 0-350mm range, power required 5v, and other is load cell with 0-20kg, output 0.5mv/v, both have analog signals, i tried many times to connect them with ni-6009 but when i am aquiring analog signals there is nothing, kindly tell me how and where i connect wires of sensors or i need any other device or something else, i just need displacement data in mm, and force data in n/mm2.

[irPaul]

As Bob_Schor said, provide some documentation (manuals!) of the devices. Or at least the manufacturer & type of the devices.

The 0-350 mm range does not say anything about the output voltage - more detailed information is needed to help you.

Also the 5V power required is important, as Bob mentioned. Do you have separate power supply to feed 5V to the sensors? The 0.5 mV/V indicates that the load cell also needs an input voltage. Without it, of course the sensors cannot output anything. The NI-6009 cannot supply this voltage.

[sher786]

thank you sir for your respnse, here i am attaching specfication of load cell and displacement sensor, my sensor range ia 0-350 mmmy load cell range is 0-20 kg

[GerdW]

Hi sher,

my sensor range ia 0-350 mm

From that specs it seems it is a simple potentiometer-type sensor (aka voltage divider).

All it needs is a simple power supply of 5V and you get a voltage signal back. Even your USB6009 can deliver the ~1mA needed for this 5kOhm resistor.

That spec surely also contains a sheet  where all needed wire connections are described…

For your load cell a "better" power supply is needed: it should be as stable as possible (within error limits).

You need about 15mA at 10V (or ~7mA at 5V): use an external power supply with a linear voltage regulator for excitation.

Then read in the voltage signal and do the scaling on your own. Those simple USB600x-boxes don't support the "strain" measurement of DAQmx very good because of their missing internal excitation feature.

basially i am agricultural engineer thats why i have not too much knowledge about these

When you don't know much about (electrical) measurements you should read a book on that topic.

As an engineer you should have learned to know how to acquire knowledge…

[irPaul · Accepted solution]

Okay, that's at least sufficient documentation to start.

For reference here also a link to the USB-6009 manual: http://www.ni.com/pdf/manuals/371303n.pdf

Let's start with one sensor first, to see that it works. The displacement sensor needs a voltage input ("Operating Voltage") of 5, 10 or 24V. The operating current is <2 mA according to specs, and the USB-6009 can supply 200 mA. That means this sensor can be directly connected to the USB-6009 🙂

Wire the input + and - of your sensor to the +5V (pin 31) and GND (pin 32) on the USB-6009, and the output to for example Analog In 0 (pin 2 & 3).

Next, use the DAQmx examples I posted earlier to at least get the voltage read-out from this channel. Or try it first with the NI-MAX.

The specs show that the output should be 0-5V, corresponding to the 0-350 mm range (0V = 0 mm, 5V = 350 mm, so displacement in mm = voltage * 70).

That should be enough to get you started. If it does not work, please attach a photo of the wiring and the VI used for read-out.

[sher786]

thank you very much dear sir, my displacement sensor problem is solved, now i need the load cell solution, because when i connect this, this is not showing in force section but it shows in voltage, so please tell me how i calculate the force(n/mm2) from this voltage data or can i directly get force data. 

[GerdW · Accepted solution]

Hi sher,

how i calculate the force(n/mm2) from this voltage data or can i directly get force data.

You read in a (small) voltage signal.

And you know the sensitivity (like 2mV/V), given for the full range signal (?).

You know the full scale range.

You know the voltage supply you used for your load sensor.

Now all you need is to apply simple math: load = voltage_signal * sensitivity * voltage_supply * 1/full_range…

Keep in mind: those simple load sensors have a rather large offset error (like ±1%FS in your specs). You need to apply some "zeroing" feature to account for such errors. This type of question comes up very often and is already explained a few times in the LabVIEW forum…