77
Non-Silenceable Signal
For audible devices such as bells and piezo mini-horns that may not be silenced either
manually or automatically. While sounding, these follow the pattern appropriate for the
condition: the configured evacuation code (default is temporal code) during single-stage
alarm, or two-stage general alarm, or the alert code during a two stage system's alert
(first) stage.
Coded Signal
For audible devices such as bells and piezo mini-horns that may be activated in code.
The code consists of 4 digits with each digit consisting of 1-15 pulses on the signals.
Each coded circuit can sound the complete code 1 to 15 times after which signals go
silent or revert to programmed General Alarm rate.
Note: The NFPA-72 and ULC-S527 specify temporal tone. However, for retrofits of
systems that were previously approved, coded signalling is allowed.
Strobe
For visual devices such as strobes that use no code patterns (they are continuous).
Indicating (Signal) Circuit
Type
Description
