EtherCAT igh函数尝试

尝试igh函数的功能，加深对不同函数的认识，总结相关函数的用法。

1.ecrt_master_get_slave

/** Obtains slave information.
 *
 * Tries to find the slave with the given ring position. The obtained
 * information is stored in a structure. No memory is allocated on the heap in
 * this function.
 *
 * \attention The pointer to this structure must point to a valid variable.
 *
 * \return 0 in case of success, else < 0
 */
int ecrt_master_get_slave(
        ec_master_t *master, /**< EtherCAT master */
        uint16_t slave_position, /**< Slave position. */
        ec_slave_info_t *slave_info /**< Structure that will output the
                                      information */
        );
        
//example----------------------------------------------------------------------
typedef struct {
    unsigned short  position;
    unsigned int    vendor_id;
    unsigned int    product_code;
}EL_Slave_t;

int  GetSlavesInfo(EL_Slave_t* slaves, int num)
{
    ec_master_t* master = ecrt_request_master(0);
    ec_slave_info_t  tmps;
    int  i;
    for(i = 0;i< num;i++)
    {
        if(ecrt_master_get_slave(master, i, &tmps) == 0)
        {
            (slaves + i)->position = tmps.position;
            (slaves + i)->vendor_id = tmps.vendor_id;
            (slaves + i)->product_code = tmps.product_code;
            printf("slave position:%d,vendor_id:%d,product_code:%d,name:%s\n",
                   tmps.position, tmps.vendor_id, tmps.product_code, tmps.name);
        }
        else
            break;
    }
    ecrt_release_master(master);
    return i;
}

int main(int argc, char *argv[])
{
	...
    EL_Slave_t  slaves[16];
    int num = GetSlavesInfo(slaves, 16);
    printf("num = %d\n",num);
    ...
}

//测试结果、终端输出
slave position:0,vendor_id:9,product_code:37458,name:LAN9252-EVB-HBI
slave position:1,vendor_id:2,product_code:72100946,name:EK1100 EtherCAT-Koppler (2A E-Bus)
slave position:2,vendor_id:2,product_code:131608658,name:EL2008 8K. Dig. Ausgang 24V, 0.5A
slave position:3,vendor_id:2,product_code:131608658,name:EL2008 8K. Dig. Ausgang 24V, 0.5A
slave position:4,vendor_id:2,product_code:131608658,name:EL2008 8K. Dig. Ausgang 24V, 0.5A
num = 5