SCXI-1314 wiring

[RobTom]

JK1, I want to zero out the strain the weight of my motor is producing on the cantilever beam. Do you know how I would do that in the labview?

[CharlesD]

PLease check out the following shipping example that includes Strain gauge nulling and shunt calibration for the SCXi 1520(Assuming this is the module that your 1314 connector block is being used with). 

Either of the following VIs could be used as a template of howto implement calibration:

Cont Acq Strain Samples (With Calibration) - SCXI 1521.vi 
Cont Acq Strain Samples (With Calibration).vi

These two vis Can be found under: .....\National Instruments\LabVIEW 8.6\examples\DAQmx\Analog In\Measure Strain.llb

This should be able to help you considerably!

[RobTom]

Charles, thanks for the help so far. I got the system properly calibrated. However, I have one last problem and that is related to the original question I asked. I am confused on how to wire my two strain gages in a half bridge 1 configuration. I have looked at the diagram in the 1521 manual and I have no clue where the white, red, and black wires from my strain gages should go. The way I looked at it originally was the R4 gage's red wire goes to P+. R4 gage's white wire is spliced with the other white wire of R3 gage. The spiced wire branches to S+ and SCA. R3 gage's black wire goes to P-. Is this correct? If so, where does the black wire of R4 gage go? Does it not connect to anything?

[RavensFan]

Do you want your half bridge 1 setup to use the shunt cal resistor?  In my opinion, the shunt cal probably isn't necessary, and it just confuses all the wiring.

Without the shunt cal, you can use just 2 wires from each gage, red and black.  The red of the R4 gage goes to P+.  The red of R3 and the black of R4 goes to S+ and it is actually best of those two are joined togther close to the gages and only one wire goes back to S+.  The black of R3 goes to P-.

If you put in the shunt cal resistor, then take the white of R3 to one SCA and another wire whichever is unused (red R3, black R4, white R4) to the other SCA.  Remember in the sketch, any wire in the schematic that has an RL resistor shown means it is a long wire that has an inherent resistance.  In that drawing only 5 RL's are shown so you only need to use 5 total wires that have roughly equivalent length.