Module fb 

Function blocks for control programs (IEC 61131-3 inspired).

Function Blocks

Reusable function blocks for control program development, inspired by the IEC 61131-3 standard. Each block is a stateful struct that you call cyclically (once per scan) from your ControlProgram::process_tick implementation.

Available Blocks

Block	Description
RTrig	Rising edge detector (false → true)
FTrig	Falling edge detector (true → false)
Ton	Timer On Delay — output activates after a duration
SimpleTimer	One-shot timer for imperative start/check patterns
StateMachine	State machine helper with automatic timer management
BitResetOnDelay	Resets a boolean after it has been true for a duration
RunningAverage	Accumulates values and computes their arithmetic mean
Beeper	Audible beeper controller with configurable beep sequences
Heartbeat	Monitors a remote heartbeat counter for connection loss
Shutdown	Non-blocking system shutdown initiation and cancellation via IPC

Usage Pattern

All function blocks follow the same pattern:

1. Create the block once (typically in your program struct)
2. Call it every scan cycle with the current inputs
3. Read its outputs to drive your logic

use autocore_std::fb::{RTrig, Ton};
use std::time::Duration;

struct MyProgram {
    start_trigger: RTrig,
    start_delay: Ton,
}

impl MyProgram {
    fn new() -> Self {
        Self {
            start_trigger: RTrig::new(),
            start_delay: Ton::new(),
        }
    }
}

IEC 61131-3 Naming

IEC 61131-3 Name	Rust Name
R_TRIG	RTrig
F_TRIG	FTrig
TON	Ton
FB_StateMachine	StateMachine
FB_BitResetOnDelay	BitResetOnDelay
FB_RunningAverage	RunningAverage
FB_Beeper	Beeper
FB_Heartbeat	Heartbeat
FB_Shutdown	Shutdown

Structs

Beeper

Audible Beeper Controller (FB_Beeper)

BitResetOnDelay

Resets a boolean value after it has been true for a specified duration.

FTrig

Falling Edge Trigger (F_TRIG)

Heartbeat

Heartbeat Monitor (FB_Heartbeat)

RTrig

Rising Edge Trigger (R_TRIG)

RunningAverage

Running Average (FB_RunningAverage)

Shutdown

SimpleTimer

Simple One-Shot Timer

StateMachine

State Machine Helper (FB_StateMachine)

Ton

Timer On Delay (TON)

Traits

Averageable

Trait for types that can be used with RunningAverage.