7.2.1.1 Priority of Signals. 
A carbon monoxide alarm signal shall take precedence over supervisory or trouble signals.

7.2.1.2 Carbon Monoxide Alarm Signal Disposition.
   7.2.1.2.1 The actuation of a carbon monoxide detector or system shall be distinctively indicated as a carbon monoxide alarm signal.

   7.2.1.2.2* Servicing of a system in alarm that cannot be reset shall be in accordance with Chapter 8 and shall occur within 4 hours of the carbon monoxide alarm signal.

7.2.1.3 Carbon Monoxide Trouble Signal Disposition.
   7.2.1.3.1 Upon receipt of a carbon monoxide trouble signal, the responsible party(s) shall be notified.
   7.2.1.3.2 Servicing of a system in trouble shall be in accordance with Chapter 8 and shall occur within 4 hours of the trouble indication.

A.10.14.9 The purpose of automatic trouble re-sound is to remind owners, or those responsible
for the system, that the system remains in a fault condition. A secondary benefit is to
possibly alert occupants of the building that the fire alarm system is in a fault condition.

10.14.9.1 The audible and visible trouble signal shall automatically reactuate at the control
unit every 24 hours or less until trouble signal conditions are restored to normal.
As in 10.11.8.1 and 10.13.6.1, the requirement in 10.14.9.1 serves as an important reminder, every
24 hours at the protected premises control unit, that a trouble condition still exists and needs to be
restored to normal. The ongoing detection of a trouble condition means that the system has a fault
condition or impairment that needs to be corrected (see 10.20.1 and 14.2.2.2.2). In accordance with
10.14.6, actuated trouble signals must be manually silenced.