Elevator Intercom Digital Concentrator/Splitter

Market Demand Analysis:

Traditional elevator intercom systems use twisted pair cables for transmission. When there are multiple elevators, the twisted pairs are typically directly paralleled together at the central end. Usually, up to 10 units can be paralleled. When the quantity increases, a 1-to-8 concentrator is commonly used, with each downstream port of the concentrator capable of paralleling six or seven remote units.

Figure 1: Twisted Pair Direct Connection Mode

Figure 2: Expansion Mode via Splitter

As community areas expand and communication technology evolves toward fiber optics, twisted pair cables in communities are becoming increasingly scarce, and distances also exceed the typical transmission range of twisted pair cables.

Twisted pair cables are being replaced by fiber optics. After elevator intercom signals are transmitted through optical terminals, the signal level drops from the original approximately 10V to 2–3V. When using the original concentrator with multiple paralleled channels, operation becomes unstable. Therefore, a new type of concentrator is required that can disconnect unused audio channels.

Since fiber optics isolate the voltage and current transmission characteristics of twisted pair cables, the electrical interface section must be able to detect voltage and current changes, transmit these changes to the interface at the other end, and emulate such changes.

The IDM ZHD01-028 Elevator Intercom Concentrator works in conjunction with elevator intercom optical terminals to achieve expansion of the elevator intercom system. Due to system address configuration limitations, it can support up to 250 elevator intercom channels.

Figure 3: Aggregation of Optical Terminal Lines via Digital Elevator Intercom Concentrator

Technical Features:

1. Level detection and control of elevator intercom signaling interfaces, providing idle and busy status indication;

2. Reception and forwarding of elevator intercom signaling messages, enabling conversion of messages from audio transmission to data interfaces;

3. Switching of intercom audio channels — unused channels are no longer paralleled into the line, reducing audio line loss;

4. Flexible configuration of terminal numbers for each downstream port, increasing system capacity;

5. Support for multi-level system cascading, avoiding direct paralleling on twisted pair cables to prevent degradation of signal transmission performance;

6. Device configuration can be conveniently performed via mobile phone Bluetooth.