CAN_DEVCTL_SET_MID

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Set the message ID

Synopsis:

#include <sys/can_dcmd.h>

#define CAN_DEVCTL_SET_MID   __DIOT(_DCMD_MISC, CAN_CMD_CODE + 1, uint32_t)

Arguments to devctl():

Argument Value
filedes A file descriptor that you obtained by opening the device. This must be for a transmit or receive mailbox (e.g., /dev/can1/rx2).
dcmd CAN_DEVCTL_SET_MID
dev_data_ptr A pointer to a uint32_t
n_bytes sizeof(uint32_t)
dev_info_ptr NULL

Description:

This command sets the message ID for the mailbox associated with the file descriptor.

Input:

The message ID. The form depends on whether or not the driver is using extended MIDs:

  • In standard 11-bit MIDs, bits 18–28 define the MID.
  • In extended 29-bit MIDs, bits 0–28 define the MID.

Output:

None.

Example:

int      ret;
uint32_t val;

if( (fd = open( "/dev/can1/rx2", O_RDWR)) == -1 )
{
    printf("open of %s failed \n", devname);
    exit(EXIT_FAILURE);
}

/* Set the new message ID. */
val = strtoul(optarg, NULL, 16);

if(EOK != (ret = devctl(fd, CAN_DEVCTL_SET_MID, &val, sizeof(val), NULL)))
{
    fprintf(stderr, "devctl CAN_DEVCTL_SET_MID: %s\n", strerror(ret));
}

See also:

CAN_DEVCTL_GET_MID, CAN_DEVCTL_SET_MFILTER

devctl() in the QNX OS C Library Reference

canctl in the Utilities Reference

Page updated: