# Pulse counter

Process

Counts rising-edge pulses up and/or down within configurable limits. Supports clamp and wrap overflow modes.

Pulse counter

I+

I-

Pulse counter ver: 1

# Inputs

ID	Abbrev	Name	Type	Default	Description
`increment`	`I+`	Increment	BOOLEAN	`false`	Pulse input. Each rising edge increments the counter value by 1.
`decrement`	`I-`	Decrement	BOOLEAN	`false`	Pulse input. Each rising edge decrements the counter value by 1.
`reset`	`R`	Reset	BOOLEAN	`false`	Pulse input. Rising edge resets the counter to the configured start value. Dominant input.

# Outputs

ID	Abbrev	Name	Type	Default	Description
`value`	`V`	Value	NUMBER	`0`	Current counter value.
`at_upper_limit`	`UL`	At upper limit	BOOLEAN	`false`	True when the counter value equals the configured upper limit.
`at_lower_limit`	`LL`	At lower limit	BOOLEAN	`false`	True when the counter value equals the configured lower limit.

# Configuration

ID	Name	Type	Default	Description
`start_value`	Start value	NUMBER	`0`	Initial counter value and value restored on reset. Must be within the configured limits. Details: ≥ `lower_limit` ≤ `upper_limit`
`lower_limit`	Lower limit	NUMBER	`0`	Minimum counter value. Must be less than the upper limit. Details: < `upper_limit`
`upper_limit`	Upper limit	NUMBER	`1000`	Maximum counter value. Must be greater than the lower limit. Details: > `lower_limit`
`overflow_mode`	Overflow mode	ENUM	`0`	Behavior when the counter reaches a limit. Clamp stops at the limit. Wrap continues from the opposite limit. Details: Values: Clamp, Wrap

# State

ID	Name	Type	Default	Description
`prev_increment`	Previous increment state	BOOLEAN	`false`	Stores the previous state of the increment input to detect rising edges.
`prev_decrement`	Previous decrement state	BOOLEAN	`false`	Stores the previous state of the decrement input to detect rising edges.
`prev_reset`	Previous reset state	BOOLEAN	`false`	Stores the previous state of the reset input to detect rising edges.

# Source Code

View Volang source

channel = input::channel()
value = input::value()

// Handle "reset" input first (dominant input)
if (channel == "reset") {
    prev_reset = state::get("prev_reset")

    if (value and !prev_reset) {
        // Rising edge on reset - restore start value
        start_value = config::get("start_value")
        output::set("value", start_value)
        output::set("at_upper_limit", start_value == config::get("upper_limit"))
        output::set("at_lower_limit", start_value == config::get("lower_limit"))
    }

    state::set("prev_reset", value)
    return
}

// Handle "increment" input
if (channel == "increment") {
    prev_increment = state::get("prev_increment")

    if (value and !prev_increment) {
        // Rising edge on increment
        current = output::get("value")
        upper_limit = config::get("upper_limit")
        lower_limit = config::get("lower_limit")
        overflow_mode = config::get("overflow_mode") // 0=Clamp, 1=Wrap

        if (current < upper_limit) {
            current = current + 1
        } else if (overflow_mode == 1) {
            // Wrap around to lower limit
            current = lower_limit
        }
        // else: Clamp - no change

        output::set("value", current)
        output::set("at_upper_limit", current == upper_limit)
        output::set("at_lower_limit", current == lower_limit)
    }

    state::set("prev_increment", value)
    return
}

// Handle "decrement" input
if (channel == "decrement") {
    prev_decrement = state::get("prev_decrement")

    if (value and !prev_decrement) {
        // Rising edge on decrement
        current = output::get("value")
        upper_limit = config::get("upper_limit")
        lower_limit = config::get("lower_limit")
        overflow_mode = config::get("overflow_mode") // 0=Clamp, 1=Wrap

        if (current > lower_limit) {
            current = current - 1
        } else if (overflow_mode == 1) {
            // Wrap around to upper limit
            current = upper_limit
        }
        // else: Clamp - no change

        output::set("value", current)
        output::set("at_upper_limit", current == upper_limit)
        output::set("at_lower_limit", current == lower_limit)
    }

    state::set("prev_decrement", value)
    return
}