How to write and read channels in Wago 750-350 ethercat? - c++

Question

I have an EtherCat Wago 750-354 and I would like to do simple test for the output module (turn the leds on and off). I read the tutorial and I wrote short code for testing but I am not able to write the output module.
The tutorial link is: https://openethercatsociety.github.io/doc/soem/tutorial_8txt.html
and here is my code:
#define SLAVE_NR 1
void set_output_int8 (uint16 slave_no, uint8 module_index, int8 value)
{
uint8 *data_ptr;
data_ptr = ec_slave[slave_no].outputs;
/* Move pointer to correct module index*/
//data_ptr += module_index * 8;
/* Read value byte by byte since all targets can't handle misaligned addresses */
*data_ptr++ = value;
}
void set_output_bit (uint16 slave_no, uint8 module_index, uint8 value)
{
/* Get the the startbit position in slaves IO byte */
uint8 startbit = ec_slave[slave_no].Ostartbit;
/* Set or Clear bit */
if (value == 0)
*ec_slave[slave_no].outputs &= ~(1 << (module_index - 1 + startbit));
else
*ec_slave[slave_no].outputs |= (1 << (module_index - 1 + startbit));
}
char IOmap[4096];
volatile int wkc;
int main(int argc, char **argv)
{
int chk;
//initialise SOEM
if (ec_init("enp4s0f1"))
{
if ( ec_config_init(FALSE) > 0 )
{
std::cout<<"slave found and configured"<<ec_slavecount<<std::endl;
ec_config_map(&IOmap);
ec_configdc();
std::cout<<"Slave mapped, state to SAFE_OP"<<std::endl;
/* wait for all slaves to reach SAFE_OP state */
ec_statecheck(1, EC_STATE_SAFE_OP, EC_TIMEOUTSTATE * 4);
std::cout<<"Request operational state for the slave"<<std::endl;
ec_slave[1].state = EC_STATE_OPERATIONAL;
/* send one valid process data to make outputs in slaves happy*/
ec_send_processdata();
ec_receive_processdata(EC_TIMEOUTRET);
/* request OP state for all slaves */
ec_writestate(1);
chk = 40;
/* wait for all slaves to reach OP state */
do
{
ec_send_processdata();
ec_receive_processdata(EC_TIMEOUTRET);
ec_statecheck(0, EC_STATE_OPERATIONAL, 50000);
}
while (chk-- && (ec_slave[1].state != EC_STATE_OPERATIONAL));
if (ec_slave[1].state == EC_STATE_OPERATIONAL )
{
std::cout<<"Operational state reached for the slave"<<std::endl;
}
ec_slave[1].state = EC_STATE_INIT;
/* request INIT state for all slaves */
ec_writestate(0);
set_output_bit (SLAVE_NR, 2, 1);
ec_send_processdata();
}