"When defending, before any dice are rolled, you may discard this card to declare that half of the damage from this attack will be cancelled and the other half will be assigned to the attacker(round down); you receive no damage. The attacking ship cannont receive critical damage from this effect. Place an Auxiliary Power Token beside your ship."
The combat phase (as confirmed in other posts) is :-
1. Declare Target
2. Roll Attack Dice - The attacking player rolls their attack dice
3. Modify Attack Dice - The players spend tokens to modify the attack dice
4. Roll Defense Dice - The defending player rolls their defense dice
5. Modify Defense Dice - The players spend tokens to modify the defense dice.
6. Compare Results
7. Deal Damage
When do you declare to use the feedback pulse?
The confusion is over "when defending" would indicate 4 where as "before any dice are rolled" would indicate 2.