qmodbus 流程
The flow of a qmodbus implementation typically follows these steps:
1. Initialize the Modbus communication:
  - Create an instance of the QModbusTcpClient or QModbusRtuSerialMaster class, depending on the communication type (TCP or RTU).
  - Set the communication parameters such as the server address, port, baud rate, data bits, parity, and stop bits.
server error啥意思2. Connect to the Modbus server:
  - Call the connectToServer() method to establish a connection with the Modbus server.
  - Handle the connected() or errorOccurred() signals to check the connection status.
3. Prepare the Modbus request:
  - Create an instance of the QModbusDataUnit class to define the type and size of the requested data.
  - Set the necessary parameters such as the read or write operation, address, and number of registers or coils involved.
4. Send the Modbus request:
  - Call the sendRequest() method of the QModbusTcpClient or QModbusRtuSerialMaster instance with the prepared data unit as a parameter.
  - Handle the errorOccurred() signal to check if the request was sent successfully.
5. Wait for the Modbus response:
  - Wait for the stateChanged() signal or use a QTimer to periodically check the state of the Modbus instance.
  - If the state changes to QModbusDevice::ReplyReceived, it means the response has bee
n received and can be processed.
6. Process the Modbus response:
  - Use the result() method of the QModbusDataUnit instance to extract the requested data from the response.
  - Handle any error conditions or exceptions that may occur during the data extraction.
7. Disconnect from the Modbus server:
  - Call the disconnectFromServer() method to close the connection with the Modbus server.
  - Handle the disconnected() signal to ensure the disconnection was successful.
8. Handle any error conditions:
  - Handle the errorOccurred() signal and the QModbusDevice::Error type to address any errors or exceptions that occur during the Modbus communication.
Note that the specific implementation may vary depending on the requirements and use case. Additionally, error handling and exception management are crucial in order to ensure robust and reliable Modbus communication.

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。