Keil™, An ARM® Company

RL-ARM User's Guide

Technical Support

On-Line Manuals

RL-ARM User's Guide

RL-RTX RL-FlashFS RL-TCPnet RL-CAN Example Programs Library Reference Data Types BIT BOOL CAN_ERROR CAN_msg FILE S8 S16 S32 S64 U8 U16 U32 U64 Include Files can_cfg.h file_config.h net_config.h rtl.h rtx_can.h rtx_config.h stdio.h Reference _alloc_box _calloc_box _declare_box _declare_box8 _free_box _init_box _init_box8 arp_cache_ip CAN_init CAN_receive CAN_request CAN_rx_object CAN_send CAN_set CAN_start CAN_tx_object cgi_func cgi_process_data cgi_process_var cgx_content_type com_getchar com_putchar com_tx_active dhcp_disable fanalyse fcheck fclose fdefrag fdelete feof ferror ffind fflush fformat ffree fgetc fgets finit fopen fprintf fputc fputs fread frename fs_EraseSector fs_get_date fs_get_time fs_Init fs_ProgramPage fs_spi_EraseSector fs_spi_Init fs_spi_ProgramPage fs_spi_ReadData fscanf fseek ftell ftp_fclose ftp_fdelete ftp_ffind ftp_fopen ftp_fread ftp_frename ftp_fwrite fwrite get_host_by_name http_accept_host http_date http_fclose http_fgets http_finfo http_fopen http_fread http_get_content_type http_get_info http_get_lang http_get_session http_get_var igmp_join igmp_leave init_ethernet init_modem init_serial init_TcpNet int_disable_eth int_enable_eth interrupt_ethernet isr_evt_set isr_mbx_check isr_mbx_receive isr_mbx_send isr_sem_send main_TcpNet mci_init mci_read_config mci_read_sect mci_write_sect modem_dial modem_hangup modem_listen modem_online modem_process modem_run os_dly_wait os_evt_clr os_evt_get os_evt_set os_evt_wait_and os_evt_wait_or os_itv_set os_itv_wait os_mbx_check os_mbx_declare os_mbx_init os_mbx_send os_mbx_wait os_mut_init os_mut_release os_mut_wait os_sem_init os_sem_send os_sem_wait os_sys_init os_sys_init_prio os_sys_init_user os_tmr_call os_tmr_create os_tmr_kill os_tsk_create os_tsk_create_ex os_tsk_create_user os_tsk_create_user_ex os_tsk_delete os_tsk_delete_self os_tsk_pass os_tsk_prio os_tsk_prio_self os_tsk_self poll_ethernet ppp_close ppp_connect ppp_is_up ppp_listen rewind send_frame slip_close slip_connect slip_is_up slip_listen smtp_accept_auth smtp_cbfunc smtp_connect snmp_trap spi_hi_speed spi_init spi_send spi_ss tcp_abort tcp_check_send tcp_close tcp_connect tcp_get_buf tcp_get_socket tcp_get_state tcp_listen tcp_max_dsize tcp_release_socket tcp_reset_window tcp_send tftp_fclose tftp_fopen tftp_fread tftp_fwrite timer_tick tnet_cbfunc tnet_ccmp tnet_get_info tnet_msg_poll tnet_process_cmd tnet_set_delay tsk_lock tsk_unlock udp_close udp_get_buf udp_get_socket udp_mcast_ttl udp_open udp_release_socket udp_send ungetc Library Files Appendix

CAN_receive

Summary
#include <rtx_can.h>

CAN_ERROR CAN_receive (
    U32 ctrl,        /* CAN Controller */
    CAN_msg *msg,    /* CAN Message */
    U16 timeout);    /* Time to Wait */
Description

The CAN_receive function receives a message on the CAN controller specified by ctrl and copies it into msg.

The CAN_receive function does not clear hardware message FIFOs. So, if a message was received prior to invoking CAN_receive, that message is returned immediately. If the message FIFO is empty, CAN_receive waits (up to the specified timeout) for a message to be received.

timeoutDescription
0Return immediately.
0x0001-0xFFFEWait the specified number of RTX Kernel ticks.
0xFFFFWait infinitely.

If a message is not received by the specified time, an error is returned.

The CAN_receive function executes quickly since all data transfers use software buffers. Only in situations where the FIFO is empty is the CAN_receive function delayed.

The CAN_receive function is part of RL-CAN. The prototype is defined in RTX_CAN.h.

Return Value

The CAN_receive function returns one of the following manifest constants.

  • CAN_OK
    Success.
  • CAN_DEALLOC_MEM_ERROR
    Indicates that the memory used by the received message was not correctly deallocated.
  • CAN_TIMEOUT
    Indicates that the timeout expired before a message was received.
See Also

CAN_send

Example
#include <rtx_can.h>

__task void task_rece_CAN (void) {
  CAN_msg msg_buf;

  for (;;) {
    // Wait to receive a message.
    // When the message arrives
    // activate LEDs using data[0]

    if (CAN_receive (1, &msg_buf, 0) == 0) {
      LED_Byte (msg_buf.data[0]);
    }
  }
}