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UDP Multicast Receive

Receive data over UDP network from a remote device

Since R2021a

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  • UDP Receive block

Libraries:
Simulink Real-Time / IP

Description

The UDP Multicast Receive block receives multicast data over a UDP network from a remote device. It can receive data by using the connection between the MATLAB® development computer and Speedgoat® target computers or by using a dedicated Ethernet card. If you use a dedicated Ethernet card, use the Speedgoat configuration utility to configure the dedicated Ethernet board.

The UDP Multicast Receive block operates in a real-time application running on a target computer. The block does not operate in a model simulation on a development computer.

A maximum of 20 multicast groups can be joined. This number is determined as a product of the group address and group interface fields on the block mask.

Examples

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This example sets the block parameters for bind address to 0.0.0.0, a single group, and a single interface from which to receive multicast messages.

% for myModel, set UDP mcast rcv parameters for on group
set_param('myModel/UDP Multicast Receive',...
    'bindAddress','0.0.0.0',...
    'localPort','25000',...
    'rcvWidth','80',...
    'multicastAddress','{'225.11.11.11'}',...
    'multicastInterface','{'192.168.7.5'}')

This example sets the block parameters for bind address to 0.0.0.0, three groups, and two interfaces from which to receive multicast messages. The block joins groups 225.11.11.11, 225.11.11.12, and 225.11.11.13 on the group interfaces 192.168.7.5’ and 192.168.7.10. The block receives multicast messages for all those groups coming from any of those interfaces.

% for myModel, set UDP mcast rcv parameters for on group
set_param('myModel/UDP Multicast Receive',...
    'bindAddress','0.0.0.0',...
    'localPort','1',...
    'rcvWidth','16',...
    'multicastAddress','{'225.11.11.11','225.11.11.12','225.11.11.13'}',...
    'multicastInterface','{'192.168.7.5','192.168.7.10'}')

This example sets the block parameters for bind address to 0.0.0.0, three groups, and two interfaces from which to receive multicast messages. These settings specify multiple groups to subscribe to and the interface for receiving the multicast messages in the same order. There is a one to one mapping of group address and group interface.

% for myModel, set UDP mcast rcv parameters for on group
set_param('myModel/UDP Multicast Receive',...
    'bindAddress','0.0.0.0',...
    'localPort','25000',...
    'rcvWidth','80',...
    'multicastAddress','{'225.11.11.11','225.11.11.12','225.11.11.13'}',...
    'multicastInterface','{'192.168.7.5','192.168.7.5','192.168.7.10'}')

This example sets the block parameters for bind address to 0.0.0.0, three groups, and two interfaces from which to receive multicast messages. These settings specify multiple groups to subscribe to and the interface for receiving the multicast messages across all groups. The multicast groups receive messages from all the interfaces specified.

% for myModel, set UDP mcast rcv parameters for on group
set_param('myModel/UDP Multicast Receive',...
    'bindAddress','0.0.0.0',...
    'localPort','25000',...
    'rcvWidth','80',...
    'multicastAddress','{'225.11.11.11','225.11.11.12'}',...
    'multicastInterface','{'192.168.7.5','192.168.7.10','192.168.7.15'}')

Extended Examples

Target to Host Transmission by Using UDP

Target to Host Transmission by Using UDP

Use UDP blocks to send data from a target computer to a development computer.

Ports

Output

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Vector of uint8 containing data received over the UDP network. If no new packet is received, the data values are held. To determine whether a new packet has been received, use the Length output port.

Data Types: uint8

Number of bytes in the new packet received, otherwise 0. If more bytes are received than can be output through the receive port with width defined by Receive width, the excess bytes are discarded.

Parameters

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General Parameters

The Bind address can be either 0.0.0.0 or a multicast address. When Bind address is set to 0.0.0.0, the block binds to INADDR_ANY, which enables the socket to receive datagrams on all interfaces. This specification enables the Group address field on the block mask. When Bind address is set to a multicast IP address, the Group address field is hidden on the block mask.

If the Bind address is set to 0.0.0.0, the block also can receive unicast messages if the block is configured on a group interface over which unicast messages are sent. This unicast message receive occurs because address 0.0.0.0 allows listening to any messages on all interfaces of the target computer. To avoid this unicast message receive operation, use a multicast address as a bind address. Using that setup, the block only receives multicast messages and does not receive unicast messages.

Programmatic Use

Block Parameter: bindAddress

Specifies UDP port to receive data.

Ports 1 through 1023 and 5500 through 5560 are reserved for Simulink Real-Time communications.

Programmatic Use

Block Parameter: localPort

Determines the width of the Data output vector. If this value is less than the number of bytes in the received packet, the excess bytes are discarded.

Programmatic Use

Block Parameter: rcvWidth

This field is hidden when the bind address is a multicast address. Enter a valid IP address as a dotted decimal character vector, for example, {'224.0.0.0'}. One or more group addresses can be specified.

The UDP Multicast Receive block issues an error at model update if the group IP address is not a valid multicast address in the range 224.0.0.0 through 239.255.255.255.

Example: {'224.100.1.1'}

Example: {'224.100.1.1', '224.100.1.2'}

Programmatic Use

Block Parameter: multicastAddress

The Group interface IP address specifies the interfaces over which incoming multicast messages should be received. When the bind address is 0.0.0.0, the multicast groups specified in the field Group address receive messages over the specified group interface or interfaces. When the bind address is a multicast address, that address receives messages over the specified group interface or interfaces. Enter a valid interface IP address as a dotted decimal character vector, for example, {'192.168.7.5'}. You can also use a MATLAB expression that returns a valid IP address as a character vector. One or more group interfaces can be specified.

Example: {'192.168.7.5'}

Example: {'192.168.7.5', '192.168.7.10'}

Programmatic Use

Block Parameter: multicastInterface

Enter the base sample time or a multiple of the base sample time.

Programmatic Use

Block Parameter: sampleTime

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2021a

See Also

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