In a message dated 7/29/99, Victor Thang Van writes: > Anybody can shed some light on how analog 4-line cable works in Italy? I' ve > heard they are used to daisychain more than one telephones, and like to know > how the connections are made.
Victor: It sounds like you are referring to the inside wiring scheme used for PSTN telephone lines in Italy. The actual phone line from the central office is only two wires (just like any other country), but the telephone jack has three pins. Inside the building, the phone jacks are daisy chained in such as way that if any one phone is in use, all downstream phones are disabled. This is accomplished by a contact in the phone that uses the third wire. A rather cryptic description of this wiring scheme can be found in ETS 300 001, clause 8.2(I). Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 (voice) 781-721-0582 (fax)
