Help regarding connections of CB-68LP to the DAQ card PCI-6259

[sattti]

How to connect half-bridge strain gauge configuration to CB-68LP and how to configure it in LabVIEW ?

I have a CB-68LP and PCI-6259 DAQ card. I have installed the DAQ and connected it to CB-68LP. I need to know how to make the connections from the half-bridge strain gauge to CB-68LP and how to give input voltage and get output, the strain recorded is in the range 5-150 micro strain. It is ok even if I can just get the output voltage. please help.

thanks in advance.

[Elizabeth W]

Hello,

I would start out by configuring all of your hardware in NI Measurement & Automation Explorer (MAX) and verifying that you can read a test signal in MAX before starting in LabVIEW.

You can create a strain input task in MAX by completing the following steps (assuming you are in Windows):

1. Install your PCI-6259.  When you open MAX and look in the folder called NI-DAQmx devices, you should see your PCI-6259.
2. Right click on your PCI-6259 in MAX and select Properties.  Go to the Accessory tab and select your CB-68LP accessory from the drop down menu. 
3. Now you are ready to create a task.  Right-click on your PCI-6259 and select Create Task.
4. The Create New Task dialog will open.  Select Acquire Signals >> Analog Input >> Strain.
5. Select the channel you want to read.
6. Name the task and click Finish.
7. Adjust all the settings as needed for your application.
8. Click on the Connection Diagram tab at the bottom to see how to physically wire the strain gauge to your DAQ device.
9. Once everything is set up, use the Run button to test the task.

Once you have gotten this set up correctly, you should be able to use one of the LabVIEW shipping examples to get started with programming in LabVIEW.  To open the LabVIEW Example Finder, go to the Help menu in LabVIEW and click Find Examples.

I hope this helps.  Let me know if you need any more information!

[sattti]

Thank you very much.

I need one more info., can the DAQ detect inputs ranging in micro-volts? or should the signal be first magnified by an amplifier before being detected by DAQ?
what is the range, accuracy, and least count of voltages that can be detected by PCI-6259?

Thank you again.
Regards.

[Elizabeth W]

Hello,

All of the information you are requesting can be found in the NI 625x Specifications.

The available input ranges for your PCI-6259 are as follows: ±10 V, ±5 V, ±2 V, ±1 V, ±0.5 V, ±0.2 V, ±0.1 V.

The sensitivity of a device is the smallest voltage change that it can detect.  Assuming you are operating in the smallest available voltage range of ±0.1 V, the sensitivity of the 6259 is 6 µV.  So, if you are trying to measure a signal on the order of a couple of µV, you will need some sort of pre-amplification (or, a different measurement device).

Refer to page 5 of the specifications document linked above for accuracy information.  A forumla is provided to calculate accuracy based on a number of factors including the input range, the temperature, and the voltage level being measured.

Hopefully this answers your question; if not, let me know.

[sattti]

Thank you very much for the help, Elizabeth.

[lodhi]

Hi,can anyone help me in choosing Data acquisition card (Daq)to interfaced with receiving antenna operating at GHz.
Actually ,it is a project ,that I have to design a system consisting of RX antenna at GHz,interfaced with daq card which is further to PC.
My task is to find the radiation pattern of this antenna, also this receiving antenna is rotated 360 degree ,for each angle this system will record E or H field reading then after 360 rotation E or H plane pattern will display on visual monitor.
Also this motor rotation is controlled by Daq.
We want to make our own antenna measurement same as Lab volt system (lab volt 9507-5).
So could some body help me on choosing Daq card no,along with that platform on which we can program it i.e.. C,C++,etc.

Thank you!