viper 350 plus, push arm button twice

I recently installed a viper 350 plus and noticed some strange behavior. If I push the lock button, wait a half second, and push it again then the siren will sound. It alternates the siren for a couple seconds then chirps twices, then siren, then chirps twice, repeat. I didn't want to keep fooling with it and annoy all the neighbors so I haven't experiemented much more.

Confusing thing is I can't find anything about this in the viper manual. Panic mode is s dedicated button, so it shouldn't be engaging panic mode. Pressing the lock/arm button multiple times is supposed to enable a sensor bypass mode.

Anyone else install this system and note whether or not it does this??