The pressure control is a central part of the Pressure Control application algorithm. Reaching and maintaining the pressure setpoint is the goal of the algorithm's operation by adjusting the damper based on the current differential pressure measurements.
Pressure Sensor
One of the essential configuration settings for a proper functioning of the Pressure Control example application is selecting the pressure measurements source. The available options are:
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dedicated universal input, U4 (connected sensor),
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network.
Automatic Detection
Additionally, the Pressure Control application has a mechanism to provide an automatic pressure sensor detection in case the selected pressure source does not provide any value. First, the application checks the dedicated U4 input and if no sensor is connected, it proceeds to check the value from the network. In case all these steps fail to provide the measured pressure, the algorithm uses the pressure setpoint value, which forces the application to stop work.
Note
In case more than one pressure source is connected and active (for example, the sensor connected to the U4 input and network), it is possible to indicate one of them as a leading one using the Input Selector slot (PressureSelector component in the PressureSelector folder of the Pressure Control example application) or calculate an average using the averaging slot (the same location).
Pressure Setpoint
Pressure setpoint is fundamental for the pressure control setting in the Pressure Control example application’s algorithm. It determines the pressure setpoint calculations regardless of the area’s occupancy status.
For pressure control, information on the measured pressure in the room from the differential pressure sensor connected to the U4 input or from the network is required. Generally, if there is no pressure measurement, pressure control based on the pressure control loop is disabled.
The application starts the control loop if the pressure sensor measurement is valid and the room pressure is above the pressure setpoint (for positive setpoint) or below the pressure setpoint (for negative setpoint) by opening or closing the damper accordingly.
Pressure Control Loop
The pressure control loop in the Pressure Control example application determines the pressure demand based on the pressure sensor measurements (connected to the U4 input) and the corresponding pressure setpoint. It operates according to the sensor validation.
Pressure control loop settings are only available from iC Tool and must be adjusted to the current room:
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Kp: default 5.0,
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Ki: default 0.33,
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Kd: default 0.0.