Elevator Intercom Digital Concentrator/Splitter

Market Demand Analysis: Traditional elevator intercom systems use twisted-pair cables for transmission. When multiple elevators are involved, the twisted pairs are typically directly paralleled at the central end. Usually, no more than 10 units can be paralleled in this manner. When the number 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 cabling in communities is becoming increasingly scarce, and distances often exceed the typical transmission limits 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 must be capable of detecting voltage and current changes, transmitting those changes to the interface at the other end, and simulating such changes. The IDM ZHD01-028 Elevator Intercom Concentrator is designed to work in conjunction with elevator intercom optical terminals to expand the capacity of elevator intercom systems. 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 the elevator intercom signaling interface, 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 interface, 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.