Modbus Component

The Modbus protocol is used by many consumer and industrial devices for communication. This component allows components in ESPHome to communicate to those devices. Modbus requires a UART Bus to communicate.

# Example configuration entry
uart:
  ...

modbus:

Configuration variables:

  • flow_control_pin (Optional, Pin): The pin used to switch flow control. This is useful for RS485 transceivers that do not have automatic flow control switching, like the common MAX485.

  • send_wait_time (Optional, Time): Time in milliseconds before a new modbus command is sent if an answer from a previous command is pending. Defaults to 250 ms. If multiple modbus devices are attached increasing this value can help avoiding to to overlapping reads. When 2 devices are sending a command at the same the response read from uart can’t be assigned to the proper design. This value defines the maximum queuing time for a command before it is send anyways.

See Also