Collocate the system
Audio direct-call outdoor unit: Maximum user quantity is 4-24, if more than 24 users, we can select digital outdoor unit.

Audio indoor phone: The indoor phones with different type have the same function, different outcrust, we can select one or several to install in one apartment.

Audio UPS power supply: Having automatic charge up circuit. If having storage battery, the power supply can maintain the system working for 24 hours after power fails.

Storage battery: Optional.

Common Decoder( connect to 4 users): Calculated according to the scale of preject and the real situation in practice by right method.

Function and usage
This system can come into using after cabling, wiring, debugging according to this manual. The visiter press the room number with ont button, corresponding indoor phone will ring, the owner picks up the handset to talk with the visitor, press the unlock button to unlock the electric lock. If the owner is not at home, the ring will stop in 45s, and the outdoor unit comes into standby statue.

Where to apply
This system is low-cost, convenient to install, having high performance, mainly applied to multi-floor apartment building.

Compatibility, Extensible and Whether to Come into a Network
Compatibility: This outdoor unit can exchange with the digital unit of E-system.
Extensible: Extent to outdoor unit with access control system of RFID card. But it need exchange the outcrust and increase the RFID card module. The controlling PCB needn't be exchange.
Whether to Come into a Network: This system cannot come into network, if need net work, the indoor phone is the same, but the decoder and outdoor unit should be exchanged to network type, the main stem cable should add 2 cores, the branch cable is no change.