This VIs are developed to use a point by point derivative in LV FPGA, the two point version is based on the derivative function found on LabVIEW and the three point version was developed in case a different approach was needed with a little bit of more precision. Take on account that the fixed point values must be changed in cas you want a different precision.
Francisco Arellano
National Instruments Mexico
Field Systems Engineer - Energy Segment
www.ni.com/soporte