You are able to link logic to effect computers so most would expect that they were turned on/enabled if you give them a true signal.
This is not the case, not entirely sure if this is a missing/overlooked feature but then the game should not allow you to link to blocks where logic signals have no influence over.
For example you can link logic to system blocks too (power reactor, thrust,...) yet that doesn't do anything either.
How to reproduce:
# use a defensive effect like ion, put it on a ship with some shields
# shoot a cannon at it and note how much damage you did
# attempt the same thing when you enable that ion with a logic button
# you'll do the same amount of damage so ion doesn't work