alpine sec car alarm chirp, then three c

Dear Experts, I have a 96 HOnda Accord with an Alpine Car Alarm. SEC-100S, or SEC-150R is the manual I have. I left the lights on, and drained the battery. Tried to open the car with the remote. It wouldn't open. Opened the car with the key. Alarm tried to go off. Lots of clicking, but no siren, because little battery power. Got a boost. Alarm went off with more power. Turned ignition. Stopped. Got the car started, and charged. Before, when I locked the car, and set the alarm with the remote, I pressed the button, and the lights/chirp went off once. ----> Here is the symptom.   But now, when I lock the car, it gives a single chirp. Then, a few seconds later, it gives three chirps. Any ideas what this (three chirps) is, and how to turn this off? Thanks a lot!

Have you managed to fix this? I believe the three chirps sound when a door is left open. It might be a faulty door sensor.