Analysis: Calculating Integral and Derivative Values

Analysis Function Block

Pin Diagram

This figure shows the pin diagram of the Analysis function block:

Functional Description

The Analysis function block calculates the integral and derivative values of a series of input. The output starts with zero at the rising edge of i_xEn. The integral value increases in multiples of interval input.

In each scan both the integral output and the derivative output is updated based on the interval value.

An error is detected if the interval value is equal to/less than zero or if the input is out of range or if the integral or derivative outputs exceed 3.4e⁺³⁸.

Integral = Integral + (Current Input + Previous Input) / 2 * Interval.

Derivative = (Current Input - Previous Input)/ Interval.

Example

Input = 10 (Previous input: 0), Interval = 10, then the outputs after the first cycle of execution are as below:

oIntegral = 0 + (10+0) / 2 * 10 = 50

oDerivative = (10-0)/ 10 = 1

Input Pin Description

This table describes the input pins of the Analysis function block:

Input	Data Type	Description
i_xEn	BOOL	TRUE: FB enabled FALSE: FB disabled
i_rIput	REAL	Input value Range: 1.17e^-38...3.4e³⁸
i_rItvl	REAL	Input value Range: 1.17e^-38...3.4e³⁸
i_xErrRst	BOOL	TRUE: Reset the detected error. (On rising edge) (Optional)

Output Pin Description

This table describes the output pins:

output	Data Type	Description
q_xActv	BOOL	function block status output
q_rItgr	REAL	Integral value Range: 1.17e^-38...3.4e³⁸
q_rDrvt	REAL	Derivative value Range: 1.17e^-38...3.4e³⁸
q_xErr	BOOL	TRUE: i_rItvl input <= 0 or i_rIput < 1.17e^-38 or i_rIput > 3.4e⁺³⁸ or q_rItgr > 3.4e⁺³⁸ or q_rDrvt > 3.4e⁺³⁸ FALSE: No detected error