PULSETIMER.md

AxOpen.Timers.PulseTimer

PulseTimer class contains Pulse method, where logic of PulseTimer is implemented. Pulse method has following input:

VAR_INPUT 
    Parent : IAxoObject; // or IAxoContext, parent provides RTC implementation              
    inSignal : BOOL; // Trigger for start of the pulse signal
    PulseLenght : LTIME; // the length of the pulse signal
END_VAR 

The Pulse timer returns output, which is TRUE only during time counting. It creates pulses with a defined pulse duration.

The PulseTimer have also public variables which can be used to access timer results:

VAR PUBLIC
    output : BOOL; // the pulse
    elapsedTime : LTIME; // the current phase of the pulse
END_VAR 

The LOGIC of PulseTimer is following:

If inSignal is FALSE, the output is FALSE and elapsedTime is 0. As soon as inSignal becomes TRUE, output also becomes TRUE and remains TRUE for the pulse duration PulseLength. As long as output is TRUE, the time is incremented in elapsedTime, until the value reaches PT. The value then remains constant. The output remains TRUE until the pulse duration has elapsed, irrespective of the state of the input inSignal. The output therefore supplies a signal over the interval specified in PulseLength.

Example usage of Pulse timer:

USING AXOpen.Timers;


VAR 
    _signal : BOOL; // input signal, which is set somewhere in application
    _testTimerPulse: AXOpen.Timers.PulseTimer; // timer instance
    _testPulseLength: LTIME := LTIME#5s; // pulse length
END_VAR  

// call Pulse method somewhere in application
// THIS must type of IAxoObject
_testTimerPulse.Pulse(THIS, _signal, _testPulseLength);

// check for output
IF(_testTimerPulse.output) THEN

    // handle result

ENDIF;