StopWatchExt

StopWatchExt (FB)

FUNCTION_BLOCK StopWatchExt

Short description

Measurement of time intervals with plus/minus input and reset capability. Display of the total time (tElapsed) and the total time before the last measurement (tMeasured).

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
xUp	BOOL			Enable increase of the measured time
xDown	BOOL			Enable decrease of the measured time
xReset	BOOL			Reset of the stopwatch

Outputs

Name	Data type	Value range	Initial value	Function
tMeasured	TIME	0 days	0 … 10 days	Measured time before the last measurement
tElapsed	TIME	0 … 10 days		Measured duration since the last reset
xTimeError	BOOL			Indication of a stopwatch error

Function description

General

This function block is used to measure individual time intervals. The counter value is increased if the input xUp is active. The counter value is decreased if the input xDown is active. The input xUp has priority over the input xDown. The sum of the measured time intervals is shown at the output tElapsed . The sum of the measured time intervals before the last measurement is shown at the output tMeasured . The sum of the measured time intervals may be a maximum of 14400 minutes (= 10 days) and a minimum of 0 minutes. Any rising edge on the reset input (xReset = FALSE / TRUE) resets the outputs tElapsed and tMeasured to FALSE regardless of the other states. If measurement is not enabled (xUp = FALSE and xDown = FALSE) the outputs tElapsed and tMeasured are not changed.

Different reactions to an edge at the reset input xReset

Input xUp = TRUE: Each edge on the reset input resets the outputs tElapsed and tMeasured to 0. Afterwards the counter value immediately begins to increase continuously again. Input xDown = TRUE: Each edge on the reset input resets the outputs tElapsed and tMeasured to 0. The counter value does not change. The error indication xTimeError is activated as long as the input xDown remains TRUE in this state.

Error indication xTimeError

It is used to indicate functional errors (xTimeError = TRUE).

Status	xTimeError
no malfunction	FALSE
Measured time greater than / equal to 14400 minutes	TRUE
Measured time less than 1 ms and input xDown = TRUE	TRUE

CODESYS

InOut:

Scope	Name	Type
Input	xUp	BOOL
Input	xDown	BOOL
Input	xReset	BOOL
Output	tMeasured	TIME
Output	tElapsed	TIME
Output	xTimeError	BOOL