Low-voltage multi-system reuse (multi-purpose cable for one wire pair, standard for cost reduction in government projects)
Large numbers of idle spare wire pairs are commonly reused in government projects to transmit low-speed control signals, eliminating the need for separate wiring:
1. Fire protection system: Fire alarm host linkage voice, emergency broadcast control line, fire telephone extension circuit;
2. Security access control: Park gate control signals, access control card reader, duty room intercom, emergency alarm button;
3. Building automation (BA): Temperature and humidity alarm in computer room, water supply and drainage, remote voice alarm in power distribution room;
4. Confidential monitoring: Environmental alarm in confidential computer room, voice feedback for power failure alarm.

