I thought the 'amount' was for how many it will spawn at a time. Does the 'amount' differ from that if you set it to 'static'? In other words, how do you determine the set number of NPC's it will spawn?
For non-static, the Amount means: How many to keep existing simultaneously. So if you set a non-static spawner to "3", it means 3 NPCs will show up initially (short delay between spawning to let them walk off the pad), and if you kill one, another will fill the missing NPC in short order. It will maintain this number as best it can until the pad is destroyed, turned off, or whole structure power is lost (destroy the core). If you set a static spawner to "3", it means 3 NPCs will show up, and no more. It will do so regardless if the structure has power. But signals to turn it on/off still apply (although signals are generally only set to turn it ON, since once on, it spews its NPCs out then stops).
Last time I tried testing it didn't work but that was right when they got introduced. Signals work on hidden static spawners now? Hmm...
They should. However I have not tried switching a static spawner OFF with a signal. I've only had the spawner 'off' originally, then a trigger to trun them 'on', then they pour their NPCs out and stop. This helps to keep a set of static npcs from showing up until something happens (like using a switch to open a door, or crashing a light beam trap). Since its far more reliable then the wishy-washy 'spawn zone' setup