How do I make a teleporter work ONLY when all 4 sentries have been knocked out?

[StacheIsTaken]

I know how to make it when one is knocked out, but what about 4?

[PotionMaster]

Use a counter where the target number is 4, and wire each of the sentries to the counter saying “sentry knocked out → increment counter”, and have the counter open the teleporter once target number acheived.

[Dragon1]

What I did on one my maps recently was put the room with all the sentries in it, and then have a hallway connecting off of it with lasers, each one corresponding to a sentry.

[Theaxolotl]

Welcome to the forum @Dragon1!

[gimmaster12345]

I was gonna say the same thing:

@PotionMaster

Use a counter where the target number is 4, and wire each of the sentries to the counter saying “sentry knocked out → increment counter”, and have the counter open the teleporter once target number acheived.