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Systa Bus Component

The systa_bus component reads the status of solar heat energy collector controllers that use the Systa Bus protocol.

Supported Models

Section titled “Supported Models”
NameConfig Value
PARADIGMA SystaSolar Aquasystasolar_aqua

Use the config value as the model option of your sensor entries.

Hardware Connection

Section titled “Hardware Connection”

The device must be connected via a UART bus supporting the receiving line only. The UART bus must be configured at 9600bps. The controller outputs data depending on the packet type up to multiple times per second.

To convert the signal on the bus to UART that can be received by the ESPHome device, a converter circuit is needed. This circuit must apply a lowpass filter to the signal and convert the voltage to a safe level for the ESPHome device.

The following circuit uses simple components and provides electrical isolation between the bus and the ESP.

Optocoupler based Systa Bus to UART receive converter schematic
Systa Bus converter circuit

Simulation of this circuit

An alternative circuit design can be found here.

Component

Section titled “Component”

A UART bus with an RX pin at 9600 baud must be configured; the component uses it automatically when it is the only one.

# Example configuration entry
systa_bus:

WARNING

If you are using the Logger make sure you are not using the same pins for it or otherwise disable the UART logging with the baud_rate: 0 option.

Configuration Variables

Section titled “Configuration Variables”
  • uart_id (Optional, ID): Manually specify the ID of the UART bus used to connect to the device.

NOTE

Functionality of the sensors depends on the type of the device and the scheme arrangement of the hydraulic system it controls. The actual arrangement number set up can be determined from the settings of the device. Please check the user manual and assess your arrangement to determine the functionality of each sensor and name them accordingly.

Sensor

Section titled “Sensor”
# Example configuration entry
sensor:
  - platform: systa_bus
    model: systasolar_aqua
    temperature_tsa:
      name: Collector Temperature
    pump_speed:
      name: Pump Speed

Configuration Variables

Section titled “Configuration Variables”
  • model (Required, string): The model of the connected controller. Choose one of the config values listed in the table of supported models above.

Sensors for systasolar_aqua:

  • temperature_tsa (Optional): Collector flow temperature, sensor TSA, in °C. All options from Sensor.
  • temperature_tse (Optional): Collector return temperature, sensor TSE, in °C. All options from Sensor.
  • temperature_twu (Optional): Hot water storage tank temperature, sensor TWU, in °C. All options from Sensor.
  • temperature_tw2 (Optional): Second hot water storage temperature, sensor TW2, in °C; its role depends on the hydraulic arrangement. All options from Sensor.
  • pump_speed (Optional): Solar pump speed in percent. All options from Sensor.

NOTE

Sensors are updated every time a data packet is sent by the device. Some models send data very often, possibly every second. If you are concerned about the load on the receiving database, you can add a throttle filter to the sensors.

See Also

Section titled “See Also”