Retrofitting Mikron WF41C: Distance coded homing success

case HOME_INDEX_SEARCH_START: /* This state is called after the machine has made a low speed pass to determine the limit switch location. It sets index-enable, which tells the encoder driver to reset its counter to zero and clear the enable when the next index pulse arrives. */ /* set the index enable */ H[joint_num].index_enable = 1; /* and move right into the waiting state */ H[joint_num].home_state = HOME_INDEX_SEARCH_WAIT; immediate_state = 1; home_do_moving_checks(joint,joint_num); break;

case HOME_INDEX_SEARCH_WAIT: /* This state is called after the machine has found the home switch and "armed" the encoder counter to reset on the next index pulse. It continues at low speed until an index pulse is detected, at which point it sets the final home position. If the move ends or hits a limit before an index pulse occurs, the home is aborted. */ /* has an index pulse arrived yet? encoder driver clears enable when it does */ if ( H[joint_num].index_enable == 0 ) { /* yes, stop motion */ joint->free_tp.enable = 0; /* go to next step */ H[joint_num].home_state = HOME_SET_INDEX_POSITION; immediate_state = 1; break; } home_do_moving_checks(joint,joint_num); break;

case HOME_SET_INDEX_POSITION: // nr_ref_marks is 0 at the beginning of the homing sequence // distance_coded is a flag indicating that we have distance coded glasscales at hand /* - When the first index mark is found homing goes into the if() statement and from there back to search for another index mark. - When the second index mark is found homing goes into the else if() statement and calculates the correct 'home_offset' - As state was not changed in the else if() statement homing goes one more time into HOME_SET_INDEX_POSITION but this time in to the else section doing the regular offset setting */ if(distance_coded && nr_ref_marks < 1) { raw_trigger_pos_1 = current_raw_pos - current_pos; ++nr_ref_marks; H[joint_num].home_state = HOME_INDEX_SEARCH_START; //sent it back to index mark search }else if(distance_coded && nr_ref_marks < 2){ raw_trigger_pos_2 = current_raw_pos - current_pos; ++nr_ref_marks; // calculate and set the 'home_offset' based on raw_trigger_pos_1, raw_trigger_pos_2 and current_pos }else{ //normal HOME_SET_INDEX_POSITION }