Timer function blocks

All timers take a Boolean input IN and a preset duration PT, and produce a Boolean output Q plus the elapsed time ET. The base types use TIME; the typed variants make the PT/ET width explicit. In logiccloud all three forms (TP, TP_TIME, TP_LTIME, etc.) share the same signature shown below.

Variants	Description
TP, TP_TIME, TP_LTIME	Pulse timer
TON, TON_TIME, TON_LTIME	On-delay timer
TOF, TOF_TIME, TOF_LTIME	Off-delay timer

Common I/O (all timers)

Direction	Name	Type	Meaning
Input	IN	BOOL	Trigger / start condition
Input	PT	TIME	Preset time (pulse width or delay)
Output	Q	BOOL	Timer output
Output	ET	TIME	Elapsed time

Signature (shared by all timer types and their typed variants):

FUNCTION_BLOCK TP   // also TON, TOF
VAR_INPUT
    IN : BOOL;
    PT : TIME;
END_VAR
VAR_OUTPUT
    Q  : BOOL;
    ET : TIME;
END_VAR
END_FUNCTION_BLOCK

TP — pulse

Generates a pulse of fixed length PT on the rising edge of IN. Once started, the pulse runs to completion regardless of further changes on IN; ET counts up to PT and then holds. When the pulse ends and IN is low again, the timer resets.

VAR
    pulse : TP;
END_VAR

pulse(IN := trigger, PT := T#500ms);
output := pulse.Q;   // TRUE for 500 ms after each rising edge of trigger

Timing:

• Rising edge of IN → Q becomes TRUE, ET starts counting from 0.
• While ET < PT → Q stays TRUE even if IN falls.
• When ET reaches PT → Q becomes FALSE, ET holds at PT until IN is low.

TON — on-delay

Delays a rising edge. Q becomes TRUE only after IN has been continuously TRUE for at least PT. Any drop of IN resets ET to 0 and Q to FALSE.

VAR
    onDelay : TON;
END_VAR

onDelay(IN := startBtn, PT := T#2s);
motor := onDelay.Q;   // motor starts 2 s after startBtn goes high

Timing:

• IN low → ET = 0, Q = FALSE.
• IN high → ET counts up; when ET = PT, Q becomes TRUE.
• IN falls before PT is reached → timer resets, Q stays FALSE.

TOF — off-delay

Delays a falling edge. Q follows IN to TRUE immediately, but stays TRUE for PT after IN drops.

VAR
    offDelay : TOF;
END_VAR

offDelay(IN := running, PT := T#5s);
fan := offDelay.Q;   // fan keeps running 5 s after running goes low

Timing:

• Rising edge of IN → Q becomes TRUE immediately, ET = 0.
• IN falls → ET counts up; Q stays TRUE until ET = PT, then Q = FALSE.
• IN rises again before PT elapses → the off-delay is cancelled.