| 释义 |
Figure K-1 Most small KTSs are squared, meaning that every key set is configured alike, with every outside line appearing on every set. Thereby, every station user can access every outside line for both incoming and outgoing calls, and all feature presentations are consistent. In larger systems, the physical size of the telephone sets required to maintain the squaring convention would be impractical, but departmental subgroups often are squared.As illustrated in Figure K-1, all but the simplest key systems have a software-based common control unit, known as a Key Service Unit (KSU), where programmed features are stored and provided to individual users and stations based on their individual access privileges. Introduced in 1938, early 74570c11.qxd 9/11/07 12:24 PM Page 274 |