Im confused on something. While at the left or right active monitor it'll read 0000 before you activate it, once activated it'll play off a 4 digit number say (0001) then it'll briefly flash another set of numbers before going back to the original 0000 do you need the first 4 numbers aswell as the last? Also when you activate one monitor the other side flashes as well. Do you need those numbers too or only the first 4 numbers when you activate the monitor yourself?