Sensors to operate with 9205 and 9264 modules under LabView

[asazeki]

Hi, I am a beginner, and have been doing some reading.  I have 9205 input module and 9264 output module in a 9174 chassis.  I need to wire sensors to receive power (+/- 10VDC) and deliver a reading (analogue voltage); available are 2 wires for power and 2 for output reading. A GPIB communication forms part of my testing system (but my query focus now is on sensors). Need to capture in LabView.  Need advice on the early steps; thanks.

[_kb]

asazeki

Without knowing too much about your setup, the best reference I can provide to get you started is the following:

Developer Zone Tutorial: Field Wiring and Noise Considerations for Analog Signals.

Are your sensors active, and are you sending an excitation voltage out through the 9264?  Then, is the 9205 receiving direct input returned by the sensors?  How is GPIB involved?  If you can be a bit more specific in describing your system, it should be easier for us to provide better resources and advice.

[asazeki]

Thanks for responding Kyle.  My setup is a material testing machine where a cylinderal samples is gradually compressed untill failure; deformation, load and pore pressure are monitored.  I am trying to automate the process.  Allow me to zoom onto one sensor/instrument and that is a load cell (yes it is active).  The load cell has two wires for excitation (10VDC) and two wires for delivering a signal (output).  The Full range output is 2.043 mV/V, and the Zero balance is -0.033 mV/V.  My understanding module 9264 provides the DC voltage for excitation (say one pair of wires may be to Ao1/Com), and the second pair of wires to provide readings and so will be connected to 9205 (may be Ai1/Ai8).  I hope this wiring thoughts are correct.  Then to capture the reading into LabView, I need more advice (Measurement & Control).  When done properly, any change in load (i.e. if I push onto the load cell onto a solid body) should be detected.  Does this make sense, and if you how do I start the process on LabView. Please advise.

[_kb]

asazeki

First we need to make sure that you have downloaded the latest DAQmx drivers from here.  Then, we need to confirm that the devices are connected properly and that we can communicate with them.  That can be done through the Measurement & Automation Explorer -- see this.  Once you have confirmed that you have successfully connected your devices to the computer and have properly wired your sensors to the devices, you can use the DAQmx VIs in the Measurement I/O Palette on the Block Diagram.  Check out the Getting Started guide.

You will likely find the examples included with LabVIEW helpful, as well.  Open the Example Finder by selecting Help >> Find Examples... and browse through the Hardware Input and Output >> DAQmx examples.  You may even find an example that you can tweak and use for your application.

Good luck, and let us know if you run into any issues.

[asazeki]

Hi

A typical sensor I have is a load cell with the following specs:
Excitation: 10 VDC

Input/output impedence: 750/700 ohms nominal

Zero balance: -0.033 mV/Volt

Full range output: 2.043 mV/V

Two wires for excitation, and two wires for data

I need to connect 5 -6 sensors (simultaneously) similar to the load cell as part of my testing set-up

Would the NI 9264 module be able to power this sensor, to be able to capture the readings on NI 9205?  But if I needed a separate power supply, what would you recommend?

Please advise, thanks.

[_kb]

asazeki

For your setup, I'd be a bit concerned about the current drive of the 9264.  With a limit of 16 mA shared across all channels, you won't be seeing the proper excitation voltage.  I would think you want a more powerful output module.  Or you might want to just go with one of our integrated bridge-based modules.  Give us a call next week, and one of our technical reps can help you find the right setup for your application: (800) 531-5066.