How do I make my accelerometer output data at constant current?

[Jack Bristow]

How do I make my accelerometer output data at constant current? For example, the voltage output of the accelerometer varies constantly, but the output current would remain constant, this is because LABview needs a constant current input according to an NI engineer. But I have no idea what the circuit should look like or the components it should have. Thanks in advance.

[AnalogKid2DigitalMan]

I think you recieved inaacurate information. LabView is a programming language. A DAQ card is the hardware needed to interface to your accelerometer. I think they output signals in the form of voltage, not current. You may want to do a search in the Devel Zone to find more about them.

[Jack Bristow Jr.]

yes, it output voltage. but do i still to make the current constant as suggested by that NI engineer?

[Logan_K]

Jack,

What do you have your Accelerometer connected to? The way most accelerometers work is that they are powered from a constant current source, i.e. 4mA. Then, they will generate a voltage based on movement which can be read by your measuring device. So, the constant current source is generally provide by the measuring device, or some signal conditioning that is attached to the measuring device, and the voltage generated by the accelerometer is read back into the device. The products that NI sells which provide this signal conditioning for accelerometers are our DSA boards - NI-44xx, SCXI-153x, SCC-ACC01, etc... If you have any of these, then you just need to create an Accelerometer task either in MAX or using the DAQ assistant in LabVIEW.

Take a look at the DAQ Quick Start Guide, which will hopefully answer many of your questions: http://www.ni.com/pdf/manuals/373235f.pdf

-Logan