Struct SimpleTimer 

pub struct SimpleTimer { /* private fields */ }

Simple One-Shot Timer

A simple timer for one-shot timing operations. Unlike super::Ton, this timer does NOT follow the IEC 61131-3 standard and is designed for imperative “start then check” patterns rather than cyclic function block calls.

Note: For standard PLC timer patterns (delay while condition is true), use super::Ton instead. SimpleTimer is intended for one-shot use cases like “do X, wait, then do Y”.

Safety

This timer uses Instant (monotonic clock) internally, making it immune to system clock adjustments (NTP sync, manual changes, DST). This is critical for reliable timing in industrial control applications.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_millis(100));

// Timer hasn't started yet
assert_eq!(timer.is_done(), false);
assert_eq!(timer.elapsed(), Duration::ZERO);

// Start the timer
timer.start();

// Check if done (will be false initially)
assert_eq!(timer.is_done(), false);

// After waiting...
std::thread::sleep(Duration::from_millis(110));
assert_eq!(timer.is_done(), true);

// Reset for reuse
timer.reset();
assert_eq!(timer.is_done(), false);

Use Cases

• One-shot delays (“wait 500ms then continue”)
• Tracking time since an event occurred
• Non-cyclic async contexts
• Simple timeout checks

Comparison with Ton

Aspect	Ton	SimpleTimer
IEC 61131-3	Yes	No
Pattern	Cyclic call()	Imperative start()/is_done()
Auto-reset on disable	Yes	No (explicit reset())
Best for	PLC-style control	One-shot operations

Implementations

impl SimpleTimer

pub fn new(preset: Duration) -> Self

Creates a new simple timer with the specified preset duration.

The timer starts in the stopped state and must be explicitly started with start().

Arguments

• preset - The duration after which is_done() returns true

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let timer = SimpleTimer::new(Duration::from_secs(5));
assert_eq!(timer.is_done(), false);

pub fn start(&mut self)

Starts (or restarts) the timer.

Records the current time as the start time. If the timer was already running, this restarts it from zero.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_millis(100));
timer.start();
// Timer is now counting...

pub fn is_done(&self) -> bool

Checks if the preset time has elapsed since the timer was started.

Returns false if the timer hasn’t been started yet.

Returns

true if the timer was started and the preset duration has elapsed, false otherwise.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_millis(50));

// Not started yet
assert_eq!(timer.is_done(), false);

timer.start();
std::thread::sleep(Duration::from_millis(60));
assert_eq!(timer.is_done(), true);

pub fn elapsed(&self) -> Duration

Returns the elapsed time since the timer was started.

Returns Duration::ZERO if the timer hasn’t been started yet.

Returns

The elapsed time since start() was called, or Duration::ZERO if not started.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_secs(10));

// Not started
assert_eq!(timer.elapsed(), Duration::ZERO);

timer.start();
std::thread::sleep(Duration::from_millis(50));
assert!(timer.elapsed() >= Duration::from_millis(50));

pub fn reset(&mut self)

Resets the timer to its initial (stopped) state.

After calling this, is_done() will return false and elapsed() will return zero until start() is called again.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_millis(50));
timer.start();
std::thread::sleep(Duration::from_millis(60));
assert_eq!(timer.is_done(), true);

timer.reset();
assert_eq!(timer.is_done(), false);
assert_eq!(timer.elapsed(), Duration::ZERO);

pub fn preset(&self) -> Duration

Returns the preset duration for this timer.

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let timer = SimpleTimer::new(Duration::from_secs(5));
assert_eq!(timer.preset(), Duration::from_secs(5));

pub fn set_preset(&mut self, preset: Duration)

Sets a new preset duration.

This does not reset or restart the timer. If the timer is running, the new preset takes effect immediately for is_done() checks.

Arguments

• preset - The new duration after which is_done() returns true

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_secs(5));
timer.set_preset(Duration::from_secs(10));
assert_eq!(timer.preset(), Duration::from_secs(10));

pub fn is_running(&self) -> bool

Returns whether the timer is currently running (has been started but not reset).

Example

use autocore_std::fb::SimpleTimer;
use std::time::Duration;

let mut timer = SimpleTimer::new(Duration::from_secs(5));
assert_eq!(timer.is_running(), false);

timer.start();
assert_eq!(timer.is_running(), true);

timer.reset();
assert_eq!(timer.is_running(), false);

Trait Implementations

impl Clone for SimpleTimer

fn clone(&self) -> SimpleTimer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SimpleTimer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SimpleTimer

fn default() -> Self

Creates a timer with a preset of zero (will be immediately done when started).