The action #7 is being used as a boolean accumulator inside the aiscript. aiscripts do not have accums (storage variables) like map scripts do. But there is enough functionality to set/reset an action and to test-if-reset (note the logic). In the wiki these helper actions generally use the invalid action (but I guess an aim action works too)
expressly so that bots do not directly interact with it.
Note that no camp links to action 7. That then leaves it to be solely used by the aiscript.
Using a "fake" action as an accumulator is discussed in the wiki in
Long_Conditional_Tests_In_Fritzbot_ET#Fake_Actions _as_Binary_Accumulators and one is used in
FritzBot_Buttons_And_Levers (action 6).
The bindlestiff states in the map script comments that the fake action etc is to avoid exceeding the 64 keyword limit in one of the action tests.
The way the bots actually interact with the antenna rotate is by stepping on/into the invisible new floor trigger (
trigger_multiple) that were added to the map script in the
game_manager {spawn{. The associated (target'ed)
target_script_trigger connects that to a script block that
triggers(turns) the
antenna. In the
antenna's script block are added the
construct the helper_ents. These helper_ents are added invisible
func_constructibles. Then in the nav fake construct actions (e.g. action 4) are added someplace out of the way and connected by their entnums to the proper
/faketois. These fake constructs are minor constructs that are kept inactive so the bots don't try to build them. Each fake construct has an action block in the aiscript that is processed when ever the script "
constructs" the
func_constructible. Note that we don't use if_construct_built_... in this script block. We don't have a good way to script the
func_constructible's destruct in the map script. So each fake
func_constructible acts as just a one-way single event communication with the aiscript. To turn something on as well as off (repeatedly) you need 2 fake
func_constructible (func_constructs).