The SC546 is a general X10 module not specially designed for Security use. It is not registered to the SC1200.
The SC546 Chime Module is triggered by an On signal to its address.
It will sound when the system is armed. If it is set to the Light Code {Unit Code} and the House Code set in the SC1200. As the arming sends an On to the addresses set in it. Same for an alarm when the lights flash. Will also chime if you use the Light On button on the Keyfob Remotes.
So your statement sounds accurate. It will not chime on a door sensor opening or a disarm.
The SC1200 sends two addresses On and Off. Some modules don't like the second address in the mix.
I just tested one of my SC546 Chime Modules. It will only chime if set to the Second {my error earlier
} Light Code Address. Like I have A1 and A2. Mine only chimed on being set to A2.