Path: utzoo!attcan!uunet!lll-winken!netsys!vector!nobody From: westmark!dave@rutgers.edu (Dave Levenson) Newsgroups: comp.dcom.telecom Subject: Re: jack wiring info wanted Message-ID: Date: 10 Oct 88 02:01:13 GMT Sender: chip@vector.UUCP Lines: 32 Approved: telecom-request@vector.uucp (USENET Telecom Moderator) X-TELECOM-Digest: volume 8, issue 156, message 5 X-Submissions-To: telecom@bu-cs.bu.edu (TELECOM Digest Coordinator) X-Administrivia-To: telecom-request@vector.uucp (USENET Telecom Moderator) In article , smb@research.att.com writes: > I'm interested in the wiring of the 50-pin jack for for 5-line keyset > telephones (2565HKM, if it matters). So far, I've learned that > there are 3 pairs allocated to each line, with 1 pair being tip and > ring, and the third pair being A and A1. I'm especially interested > in pins that are activated by the hold button, especially per-line > hold signals. > The first pair is tip and ring. The second is A and A1. The third is L and LG -- they light the line lamp. The hold command is sent by the phone to the KTU using the A and A1 pair. This pair is normally open. It is closed when the handset is offhook and the line button is selected. If you hang up (by placing the handset onhook or by releasing the line button by selecting another line) the tip and ring circuit opens before the A and A1 circuit. If you push the HOLD button, the A and A1 circuit opens before the Tip and Ring circuit. The KTU senses this timing and decides what the lamp state should be, and what to do about the hold relays. After using 3 pair per line (on the 2565 set) there is a pair for the ringer (common audible or CA pair) a pair for the buzzer (CA-1), several pair used for on-hook dialing when the set is associated with a type 3 or 4A speakerphone, a pair for the lamp under the HOLD key (seldom used), three pair for the exclusion key (the optional pull-up plunger that replaces one of the switchhook buttons) and a couple of pair for "locally engineered circuits". -- Dave Levenson Westmark, Inc. The Man in the Mooney Warren, NJ USA {rutgers | att}!westmark!dave