Discontinuous

Relay Block

Hysteresis switch: toggles between on/off values based on input thresholds

# Relay Block

Description

A hysteresis switch that toggles between two output values. Turns on when input rises above the switch-on point, and turns off when input falls below the switch-off point. The gap between the two thresholds creates hysteresis, preventing chattering around a single threshold.

Mathematical Model

\begin{cases} y_{\text{on}}, & u(t) \ge \text{switchOn} \\ y_{\text{off}}, & u(t) \le \text{switchOff} \\ y(t-\Delta t), & \text{otherwise} \end{cases}

Parameters

switchOnPoint / switchOffPoint

Threshold values for switching. switchOnPoint should be >= switchOffPoint for proper hysteresis.

onValue / offValue

Output values for the on and off states.

switchOffPoint

Type: number (Default: -0.5)

Switch Off Point parameter description placeholder.

offValue

Type: number (Default: 0)

Off Value parameter description placeholder.

Remarks

Hysteresis gap: The gap between switchOnPoint and switchOffPoint prevents chattering around a single threshold; a wider gap means more noise immunity
State memory: The relay remembers its current state (on/off) and only transitions when the thresholds are crossed
Initial state: When the input starts between the thresholds, the relay stays in its initial off state
Comparator vs Relay: Use Comparator for noise-free digital signals; use Relay when you need hysteresis to suppress noise on a real sensor signal
Inverted logic: Swap onValue and offValue to create an inverting relay (normally-on behaviour)

Examples

Zie de ingebouwde voorbeelden in de handleiding voor een demonstratie van dit blok.