There is no "fire suppression equipment" in the avionics bay.
The "smoke detector" is situated in the air extraction duct of the avionics ventilation system. It's purpose is to detected smoke and provide (an) alert(s).
A single chime. A master caution light. An ECAM caution. A "smoke" light on the Emergency Electrical Power panel. And on the Ventilation panel, the "Blower" and "Extract Fault" light up.
Note. The sensor alerts you to the fact there is "smoke in the ventilation extraction duct", not that there is "a fire in the avionics compartment".