Transmit

The procedure for transmission in a simple network allocates a tsTxDataApp structure and stores the information required for transmission in this structure.

1. Allocates the tsTxDataApp structure as a local variable and clears the entire structure to zero.

2. Copy the data you wish to send into.auData (payload).

3. Store the number of stored bytes of the payload in .u8Len.

4. Stores .u32DstAddr (destination)

5. Stores .u32SrcAddr (the address of the sender)

6. Specify other sending options.

7. call ToCoNet_bMacTxReq().

8. When the transmission process in TWENET is finished, cbToCoNet_TxEvent() is executed.

It is exceptional for a completion event to disappear, but a timeout should be provided to handle exceptions. If the delay or retransmission delay is not set too long in the tsTxDataApp structure, then 100ms is not normally required.

Sample code

static int16 i16TransmitIoData() {
  tsTxDataApp sTx;
  memset(&sTx, 0, sizeof(sTx)); // clear by zero
  uint8 *q = sTx.auData;

  // Compose the payload
  S_OCTET(sAppData.u8AppIdentifier);
  S_BE_WORD(sAppData.sIOData_now.u16Volt);
  ...
	
  // Transmit options
  sTx.u8Len = q - sTx.auData; // packet length
  sTx.u8Cmd = TOCONET_PACKET_CMD_APP_USER_IO_DATA; // Packet type

  // destination
  sTx.u32DstAddr  = TOCONET_MAC_ADDR_BROADCAST; // broadcast address
  sTx.u8Retry     = 0x81; // retry once

  // Specifying frame counts and callback identifiers
  sAppData.u16TxFrame++;
  sTx.u8Seq = (sAppData.u16TxFrame & 0xFF);
  sTx.u8CbId = sTx.u8Seq;

  /* SimpleNet(MAC mode) allows fine-grained specification */
  sTx.bAckReq = FALSE;
  sTx.u32SrcAddr = sToCoNet_AppContext.u16ShortAddress;
  sTx.u16RetryDur = 4; // Resend interval[ms]
  sTx.u16DelayMax = 16; // Create a blur in the timing of the start of transmission(max 16ms)

  // Sending API
  if (ToCoNet_bMacTxReq(&sTx)) {
    // Success (cbToCoNet_vTxEvent() is fired when the process is finished)
    return sTx.u8CbId; // Success on putting a transmit request
  } else {
    // 失敗
    return -1; // Fail
  }
}

The S_OCTET() S_BE_WORD() S_BE_DWORD() macros are 1,2,4-byte storage macros used when uint8 *q is declared as a pointer to the payload storage area.