Automated sentry gun

Automated sentry guns were little more than automated repeating blasters controlled by a simplistic droid brain. They were equipped with a basic "Identify Friend or Foe" system that would permit allies to enter its field of fire safely. If an unidentified or enemy unit came within range it would open fire. They were strategically placed on higher elevations overlooking a field of battle and programmed to respond to some form of stimuli, usually movement.

Text and facts from the “Automated sentry gun” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.