496 Mag Knock Sensor

What does the knock sensor do?
I had my 496 Mag standard serviced for summer and they ran the scan tool on the engine. I have 168 hours. The tech said that the Knock Sesor tripped 438 times last summer. He said that the engine was adjusting automatically for detonation..??.
I have been using 87 octaine fuel as the manual states.
R-

I have a scanner and don't have any errors stored in the puter , running 87 octane myself. I have 6.2's with ECM555 computer what you have. I seen the rev limiter hit a few times though :) .The computer supposed to adjust timing according to the knock sensor signal.The inital timing should be around 8 *. Did the tech mentioned where the timing was set at ? You may have got some bad gas at one time. Wouldn't worry about it , just fill up at a gas station with fresh fuel, that go through a lot of traffic.