Software

# **Compare Input**

The **Compare Input** block evaluates a selectable system signal against a user-defined threshold using flexible comparison logic. It supports hysteresis, optional filtering, and timing control for stable and precise event detection.

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## **1. Input Source**

The user can select a signal from available system variables (e.g., coolant temperature, pressure, RPM) to use as the input for comparison.

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## **2. Comparison Modes**

Specifies how the input is evaluated relative to a defined `Value`.

- ### **Equal**

  - Output is `true` only when the input equals the specified `Value`.

  - `Deviation` is **forced to 0** in this mode — no hysteresis or tolerance is applied.

  - Ideal for detecting exact matches.

- ### **Window Compare**

  - Output is `true` when the input is within the range:

    ```

    Value - Deviation ≤ Input ≤ Value + Deviation

    ```

  - Output is `false` when the input is outside this range.

  - Useful for checking valid or safe operating windows.

- ### **LessThan**

  - Output turns `true` when:

    ```

    Input < Value - Deviation

    ```

  - Output turns `false` when:

    ```

    Input > Value + Deviation

    ```

- ### **GreaterThan**

  - Output turns `true` when:

    ```

    Input > Value + Deviation

    ```

  - Output turns `false` when:

    ```

    Input < Value - Deviation

    ```

  > These hysteresis thresholds prevent output toggling due to small signal oscillations.

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## **3. Value**

The central threshold used in all comparison modes.

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## **4. Deviation**

Defines the hysteresis band or tolerance around the `Value`.

- Used in **Window Compare**, **LessThan**, and **GreaterThan** modes.

- Helps filter out signal noise or rapid transitions.

- **Not used in Equal mode** (automatically set to 0).

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## **5. Filter Enable**

Controls how the input signal is processed and whether timing constraints are applied.

- ### **Filter Disabled**

  - Compare Input operates in **level-based mode**.

  - Output reacts **immediately** to input crossing thresholds.

  - **Delay** and **Cooldown** are **ignored**.

- ### **Filter Enabled**

  - Compare Input operates in **event-based mode**.

  - Output is triggered on **rising/falling transitions** of the condition.

  - **Delay** and **Cooldown** become active:

    - `Delay`: suppresses short glitches.

    - `Cooldown`: prevents rapid retriggering.

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## **6. Delay**

- Only evaluated when **Filter is enabled**.

- The input condition must remain valid continuously for the full **Delay time** before the output is activated.

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## **7. Cooldown**

- Only evaluated when **Filter is enabled**.

- Defines the **minimum time after the end of the trigger condition** during which new events are ignored.

- Prevents repeated or bouncing events immediately after a trigger ends.

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## **Example Configuration**

```text

Input:          Coolant Temperature

Mode:           LessThan

Value:          80

Deviation:      3

Filter:         Enabled

Delay:          50 ms

Cooldown:       200 ms

```

### **Behavior**

- Output turns **on** when the input drops below **77°C** and stays there for **at least 50 ms**.

- Output turns **off** when the input rises above **83°C**.

- After turning off, the system **waits 200 ms** before allowing another trigger.