Hello
In my experience signal form is :

Header : 650ms high and 8000ms low
Body : a set of 36 bits
bit 0 : 650ms high and 2000ms low
bit 1 : 650ms high and 4000ms low

bit 0-13 : id (seems different for each sensor. When you press test, id send id+1. When you reset power, id can be different)
bit ...