Derivative x(t) PtByPt (Not in Base Package)

Performs a discrete differentiation on the set of input data.

initialize, when TRUE, initializes the internal state of the VI.
input data is the sampled signal.
initial condition is the value used to calculate the derivative for the first and second point. The default is 0.
dt is the sampling interval and must be greater than zero. The default is 1.0. If dt is less than or equal to zero, the VI sets dx/dt to an empty array and returns an error.
dx/dt is the differentiated data.
error returns any error or warning condition from the VI. Refer to Point By Point Error Codes for more information about these conditions.