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UDP Receive

Receive UDP packets from UDP host

  • Library:
  • Embedded Coder Support Package for STMicroelectronics Discovery Boards/STM32F7xx Based Boards

    Embedded Coder Support Package for STMicroelectronics Discovery Boards/STM32H7xx Based Boards

  • UDP Receive block

Description

The UDP Receive block receives UDP packets from a UDP host. Use the block for stateless and connectionless data transmission.

With each sample, the block outputs the contents of a UDP packet as a (Nx1) array.

The block receives the packets on the port number specified in the Local IP Port parameter from the IP address specified in the Remote IP address (0.0.0.0 for accepting all) parameter. To receive packets from all the sending hosts, specify the remote IP address as 0.0.0.0. Match the port number specified in the Local IP Port parameter with the remote port number of the sending host.

You can choose to receive the UDP packets in blocking or non-blocking mode.

Note

  • Ensure to configure the Ethernet options in STM32CubeMX project. For more, see Configure Ethernet Options in STM32CubeMX for STM32 Processor Based Boards.

  • If you are having trouble using UDP to communicate with a computer, investigate if antivirus or firewall software is blocking UDP traffic. If so, try to configure the software to allow the traffic for a specific IP port number.

Ports

Output

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At each sample time, the port outputs the contents of a packet received as a data vector of the size that you specify in the Data size (N) parameter. For more information, see .

Data Types: int8 | uint8 | int16 | uint16 | int32 | uint32 | single | double | Boolean

At each sample time, the port outputs 0 when the length of data received is greater than or equal to the length specified in the Data size (N) parameter. A value of 0 indicates that the requested data is received at the given time step. Otherwise, it outputs a nonzero value, indicating that no new data is available.

For more information, see Receive UDP Packets.

Dependencies

To enable this port, select the Output error status parameter.

Data Types: uint16

Parameters

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Specify the IP address of the remote host from which the block receives packets. To receive packets from all the sending hosts, specify 0.0.0.0.

Specify the port number of the application from which you want to receive the packets. Match the local port number with the remote port number of the sending host.

  • on — When you select this parameter, the read operation runs in the Blocking mode. The read operation is blocked while waiting for the requested data to be available. If data is available, the Data port outputs data. If data is not available, the Data port waits for data.

    A task overrun occurs if the target hardware is still waiting for the data to be available when the next read operation is scheduled to begin.

    To fix overruns:

    • Increase the time step by using the Sample time parameter.

    • Reduce the length of data requested by using the Data size (N) parameter.

  • off — When you clear this parameter, the read operation runs in the Non-blocking mode. When reading data, if data is not available, the Data port contains the packet received in the previous time step. In this mode, the block does not wait for the requested data to be available.

Select the data type in which the block receives the elements from the sending host. The size of each element depends on its data type.

Specify the number of elements that you want to receive in each packet. The data size must be scalar values.

Select this parameter to display the error status during data transmission.

When you select the Output error status parameter, the block configures an output port. The port on the block is labeled as Status, indicating that the block outputs the status of the read operation at the output port.

When you specify this parameter as-1, Simulink® determines the best sample time for the block based on the block context within the model.

More About

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Version History

Introduced in R2022b