Simatic S7 SCL reference: Timers

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IEC timers (TP, TON, TOF) should definitely be called embedded from the FBs, the description of which can be found here: Call FBs
In the case of embedding, the functions must be called from the static block of the calling FB (just type TON for the data type):

	In the case of embedding, the functions must be called from the static block of the calling FB (just type TON for the data type. FBs must be called in the program in much the same way, of course the DB call must be omitted.
	The image shows the data of the embedded FBs in the IDB of the calling FB. The great advantage of this method is that the program is easy to import / export / copy, as you only need one FB definition.

The TON switch-on delay function. It monitors the positive edge of the binary signal at the IN input. If the signal persists for a specified PT time, it outputs Q. The timer is most commonly used to delay signals, for example: - in the case of a field signal, we want to make sure that not only one interference signal is received - in case of level signals we want to get a certain signal (many level signals wobble)

See: Timer operations

_FB_ TON (
	IN: BOOL ,	input	Start signal: The function monitors the positive edge of this binary signal. The timer start, if signal is TRUE.
	PT: TIME ,	input	Delay time: The delay time, example: t#12s
	Q: BOOL ,	output	Result: When the time is up, the result will be TRUE.
	ET: TIME	output	Elapsed time
);

CALL TON

TON second impuls

The example program below can be downloaded here: test_ton.scl.

Here is a description of how to import the downloaded program to the TIA Portal: Import source code to the TIA portal.

// author OB121 / Sandor Vamos
// ob121.com; 2022.04.13.
// TON example: sec impuls
// 
// More information:
// https://www.ob121.com/doku.php?id=de:s7:scl_reference_timers
// 
// FB "static" variables:
// secTakt: TON_TIME
// q, secChange: BOOL
// secCount: INT
// FB "temp" variables:
// tempInt: INT
// tempBool: BOOL
 
// TON, as sec impuls generator
#secTakt(IN:=NOT(#q),
         PT:=t#1s);
 
// For example, the "Q" parameter can be called
// directly when calling "secTakt",
// OR it can be referred to as:
#q := #secTakt.Q;
 
// when the time has elapsed, the block will be called:
// - secChange changes its status every second
// - secCount increases every second, in the range 0..9
IF #q THEN
    #secChange := NOT (#secChange);
    #secCount := #secCount + 1;
    IF #secCount > 9 THEN
        #secCount := 0;
    END_IF;
END_IF;
 
// monitor
#tempInt := #secCount;
#tempBool := #secChange;

The TOF switch-off delay function. It monitors the positive edge of the binary signal at the IN input. If the signal persists for a specified PT time, it outputs Q. The timer is most commonly used to delay signals, for example: - in the case of a field signal, we want to make sure that not only one interference signal is received - in case of level signals we want to get a certain signal (many level signals wobble)

See: Timer operations

_FB_ TOF (
	IN: BOOL ,	input	Start signal: The function monitors the positive edge of this binary signal. The timer start, if signal is TRUE.
	PT: TIME ,	input	Delay time: The delay time, example: t#12s
	Q: BOOL ,	output	Result: When the time is up, the result will be TRUE.
	ET: TIME	output	Elapsed time
);

TOF Examples

The TP pulse generator function. It monitors the positive edge of the binary signal at the IN input, and generates pulses in effect equal PT length from this. It is commonly used to extend very short-lived signals because, for example, the cycle time of a WinCC HMI is typically 1 sec. If the signals are extended for 2 seconds, the HMI can also process them.

See: Timer operations

_FB_ TP (
	IN: BOOL ,	input	Start signal: The function monitors the positive edge of this binary signal. The timer start, if signal is first time TRUE.
	PT: TIME ,	input	Extending time: example: t#12s
	Q: BOOL ,	output	Result: Q will be TRUE for the duration of the signal extension.
	ET: TIME	output	Elapsed time
);

The TONR time accumulator function. It practically collects the times, and if the input signal IN has already existed for the right amount of time, it indicates a result Q. The timer function can be reset with the reset input R to set null the amount of time collected.

See: Timer operations

_FB_ TONR (
	IN: BOOL ,	input	Start signal: The function monitors the positive edge of this binary signal. The timer running, if signal is TRUE.
	R: BOOL ,	input	Reset signal: The timer function can be reset with the reset input R to set null the amount of time collected.
	PT: TIME ,	input	Extending time: example: t#12s
	Q: BOOL ,	output	Result: After collecting the PT amount of time, the Q output will be TRUE. The function can then be restarted with the R input.
	ET: TIME	output	Elapsed / collected time
);