Pir motion sensor-60-639-95r

Have a concord 4 panel and installed60-639-95R.Went to learn sensor and open unit and received chirp from keypad. Installed in group 15. I set up detector in long hallway. The question is,does the red light suppose to come on only when alarm is set.Not sure if red light only come on when alarm is set (would save battery power) or suppose to be on all the time,when some one walks by.