Control Chain Execution

The control chain is automatically triggered whenever there is a change in the Vapor Pressure Deficit (VPD) value. This initiates a sequence of actions to adjust the environment, tailored to the capabilities of each connected device.

How It Works

1. VPD Calculation and Change Detection

The system aggregates data from all registered temperature and humidity sensors to compute an average environmental state. Using this aggregated data, it calculates the current VPD value.
When the calculated VPD deviates from the previous value, the control chain activates immediately to respond to the change.

2. Action Determination

The system compares the current VPD against predefined target ranges or setpoints. Based on the difference (delta), it decides whether to increase or reduce environmental control outputs:

• If VPD is too high → initiate cooling/dehumidifying actions
• If VPD is too low → initiate warming/humidifying actions

3. Device-Specific Adjustments

The control chain adapts its behavior depending on the device type and features:

• Dimmable Devices:
  These devices support fine-grained control through techniques such as PWM (Pulse Width Modulation) or variable voltage levels.

  • The system adjusts their output gradually, enabling smooth transitions that avoid abrupt environmental changes.
  • This allows for precise tuning and energy-efficient operation.

• Non-Dimmable Devices:
  These devices can only be fully ON or OFF.

  • The control chain uses a bang-bang control strategy (simple on/off switching) to rapidly react to VPD deviations.
  • Although less smooth, this approach ensures swift correction to maintain environmental targets.

Key Benefits

• Responsive and Dynamic:
  The system promptly reacts to environmental changes by continuously monitoring VPD and adjusting devices accordingly.

• Optimized for Device Capabilities:
  Control strategies are tailored for each device’s technical features, balancing smooth modulation and rapid response.

• Energy Efficient and Stable:
  Gradual adjustments on dimmable devices reduce wear and power consumption, while bang-bang control ensures reliable environmental regulation where fine control isn’t possible.

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This layered control approach ensures your grow environment maintains ideal conditions, improving plant health and maximizing system efficiency.