Ethernet output mailbox - Simulink, PLECS and C++ documentation

Table of Contents

The Ethernet output mailbox block allows sending 32-bit values via Ethernet using the UDP/IP protocol.

It supports two operating modes:

On-demand mode: the user manually triggers the message transmissions.
Periodical mode: the message is sent periodically, whether the data has been changed or not. The user can configure the transmission frequency.

Simulink block

Signal specification

The first input is the data to send. The accepted data type is specified by the Signal coding format parameter.
The second input is the send data signal. It is used to initiate a data transmission when the on-demand mode has been selected. Data is sent upon a rising edge on this signal.

Parameters

Ethernet port number: sets the destination port to which the data will be sent.
Ethernet IP address : selects the IP address to whom the data will be sent.
Signal coding format : defines the data type accepted in the data input (int32, uint32, or float32).
Byte order : defines the byte order in which the data will be sent. (little-endian or big-endian)
Tx frequency : sets the data transmission frequency if the periodical mode has been selected.

PLECS block

Signal specification

The first input is the data to send. The accepted data type is specified by the Signal coding format parameter.
The second input is the send data signal. It is used to initiate a data transmission when the on-demand mode has been selected. Data is sent upon a rising edge on this signal.

Parameters

Ethernet port number: sets the destination port to which the data will be sent.
Ethernet IP address: selects the IP address to whom the data will be sent.
Signal coding format: defines the data type accepted in the data input (int32, uint32 or float32).
Byte order: defines the byte order in which the data will be sent. (little-endian or big-endian)
Tx frequency: sets the data transmission frequency if the periodical mode has been selected.

The Ethernet IP addresses can be configured in the Imperix Controllers’ target window (Coder → Coder option → Target).

C++ functions

bool Eth_ConfigureOutputMailbox(unsigned int mailboxId, unsigned int port, const char* ipAddress, float maxTxFrequency = 100, tEndianness endianness = LITTLE_ENDIAN);
Code language: C++ (cpp)

Configures an Ethernet UDP output mailbox.

It has to be called in UserInit().

Parameters

mailboxId: a unique ID used to distinguish mailboxes from each other. This ID must be unique throughout the code for all ETH and CAN input/output mailboxes.
port: sets the destination port to which the data will be sent.
ipAddress: sets the destination IP address to whom the data will be sent.
maxTxFrequency: maximal frequency at which data can be sent. The frequency must be a multiple of the interrupt frequency. If the requested frequency is not achievable, it will be automatically set to the closest valid frequency.
endianness: defines the frame bytes order. (BIG_ENDIAN or LITTLE_ENDIAN)

Return value

bool: returns false if too many output mailboxes were created or if the port was already assigned to another ETH output mailbox.

int Eth_Write(unsigned int mailboxId, unsigned int data);
Code language: C++ (cpp)

int Eth_Write(unsigned int mailboxId, int data);
Code language: C++ (cpp)

int Eth_Write(unsigned int mailboxId, float data);
Code language: C++ (cpp)

These functions are used to send data on Ethernet using UDP.

They have to be called during the control interrupt.

Parameters

maildboxId: a unique ID used to distinguish mailboxes from each other. This ID must be unique throughout the code for all ETH and CAN input/output mailboxes.
data: data which will be sent. Several data types and prototypes are available.

Return value

int: returns 1 if the data has been loaded in the write buffer. Returns 0 otherwise.

Simulink block

Signal specification

Parameters

PLECS block

Signal specification

Parameters

C++ functions

Similar Posts