Yes they can all be interlinked together.
Interconnecting smoke alarms is a method of joining a series of alarms so that if any one alarm senses smoke, all the connected alarms will operate (alarm).
A 9 V signal is applied to the interconnect wire (referenced to neutral) to alarm all the other interconnected alarms.
• All interconnected smoke alarms must be supplied from the same circuit.
• A common Neutral must be used for the Interconnect to operate.
• DO NOT connect the Interconnect wire to Active or Neutral.
• A maximum of 40 Clipsal 755 smoke alarms can be installed on one circuit (wired interconnection only).
• Only Clipsal smoke alarms can be interconnected with each other.
Failure to follow these instructions may result in injury and equipment damage / malfunction.
Click on link for further information on smoke alarms:https://www.clipsal.com/search?q=SMOKE%20ALARMS