Thanks for the information.
So maybe it is just a quirk of the system.
I am still wondering why the Powerhorns momentarily sound with an Arm home or away for vlong.
Maybe it is a Powerhorn thing as with the older DS7000 Kit you set the Unit to a unused setting. As it sent the All Lights On, All Units Off commands.
The SC1200 only sends the two Light Code Addresses.
I know different Date Code PH508s act different on my SC1200A. Unfortunately I don't have any in the 08G31 to 09A03 date code range, vlong has, to try.
My 2002-2005 ones actually work OK. My two 2010 units. Sound for four cycles then stop for ten seconds then start again.