在使用libmodbus从机，我看
论坛上面有道友给了从机的例子，我就想问那个轮询的函数不需要加延时嘛？不加延时，其他的线程怎么运行呢？
sta
tic void mb_slave_thread(void *param)
{
modbus_t *ctx = RT_NULL;
int rc = 0;
modbus_mapping_t *mb_mapping = NULL; /* 线圈与寄存器 */
uint8_t mb_reply[MODBUS_TCP_MAX_ADU_LENGTH];
ctx = modbus_new_rtu("/dev/uart3", 115200, 'N', 8, 1); /* uart3 */
modbus_rtu_set_serial_mode(ctx, MODBUS_RTU_RS485);
modbus_rtu_set_rts(ctx, RS485_RE, MODBUS_RTU_RTS_UP);
modbus_set_slave(ctx, 3); /* 设置从机地址 */
mb_mapping = modbus_mapping_new(16, 16, 10, 10);
if (mb_mapping == RT_NULL)
{
rt_kprintf("modbus_mapping_new failed! n");
modbus_free(ctx);
return;
}
mb_mapping->tab_registers[0] = 'R';
mb_mapping->tab_registers[1] = 'T';
mb_mapping->tab_registers[2] = '-';
mb_mapping->tab_registers[3] = 'T';
mb_mapping->tab_registers[4] = 'h';
mb_mapping->tab_registers[5] = 'r';
mb_mapping->tab_registers[6] = 'e';
mb_mapping->tab_registers[7] = 'a';
mb_mapping->tab_registers[8] = 'd';
modbus_connect(ctx);
while (1)
{
//modbus loop
rc = modbus_receive(ctx, mb_reply);
if (rc > 0)
{
modbus_reply(ctx, mb_reply, rc, mb_mapping);
}
else if (rc == -1)
{
/* Connection closed by the client or error */
break;
}
}
modbus_close(ctx);
modbus_free(ctx);
}
这个线程不需要加延时嘛？
举报
