SECURITY SYSTEM USING CALLER IDENTIFICATION

摘要

A security system central monitoring station uses calling information from a publicly switched telephone network to select between alternative handshakes before answering a respective alarm panel call. A caller identification is detected after the first ring before lifting the receiver to complete the connection. The monitoring station retrieves the proper handshake from memory to communicate with the reporting panel and uses that handshake with the proper communications format as soon as it picks up the calling line.