Don't think artillery in factorio has control behavior, but it should be possible to mod via an overlay or a nearby combinator.
It should probably be an entirely separate mod though, kinda like SmartArtilleryWagons, adding circuit network connection and some special GUIs and behavior there for stationary artillery, to which you can then connect switches or whatever other logic.
You can control inserter that puts shells into gun(s) though, which should effectively be an on/off switch for the gun.
Can also put arithmetic combinator with memory wire there which would AND pulses from single-item inserter with 1 and enable it if button signal != combinator output, or something to that effect. This way, flipping a switch in either direction will only load and fire a single shell (pulse from inserter flipping 0/1 signal back to equal) - "push button to fire" thing.
