主机是楼宇对讲系统的控制核心部分，每一户分机的传输信号以及电锁控制信号等都通过主机的控制，它的电路板采用减振安装，并进行防潮处理，抗振防潮能力极强，并带有夜间照明装置，外形美观、大方。
The main unit is the control core of the building intercom system. The transmission signal and electric lock control signal of each extension are controlled by the main unit. Its circuit board is installed with vibration damping and moisture-proof treatment. It has strong anti vibration and moisture-proof ability and night lighting device. It is beautiful and generous in appearance.