Path: utzoo!attcan!uunet!lll-winken!netsys!vector!nobody From: chris@cos.com (Chris Rohrer) Newsgroups: comp.dcom.telecom Subject: (none) Message-ID: Date: 12 Oct 88 16:31:22 GMT Sender: chip@vector.UUCP Lines: 101 Approved: telecom-request@vector.uucp (USENET Telecom Moderator) X-TELECOM-Digest: volume 8, issue 160, message 4 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. > Here is what I have on 2565 (5 line plus hold with touchtone dial) wiring Bl/W 1 1R line 1 Ring W/Bl 26 1T line 1 Tip O/W 2 IB A1 lead (ground supply W/O 27 1H line 1 A lead for all control lines) G/W 3 L1 line 1 lamp W/G 28 LG line 1 lamp ground Br/W 4 2R line 2 Ring W/Br 29 2T line 2 Tip S/W 5 insulated and stored W/S 30 2H line 2 A lead Bl/R 6 L2 line 2 lamp R/Bl 31 LG line 2 lamp ground O/R 7 3R line 3 Ring R/O 32 3T line 3 Tip G/R 8 insulated and stored R/G 33 3H line 3 A lead Br/R 9 L3 line 3 lamp R/Br 34 LG line 3 lamp ground S/R 10 4R line 4 Ring R/S 35 4T line 4 Tip Bl/Bk 11 insulated and stored Bk/Bl 36 4H line 4 A lead O/Bk 12 L4 line 4 lamp Bk/O 37 LG line 4 lamp ground Gn/Bk 13 5R line 5 Ring Bk/Gn 38 5T line 5 Tip Bn/Bk 14 insulated and stored Bk/Bn 39 5H line 5 A lead S/Bk 15 L5 line 5 lamp Bk/S 40 LG line 5 lamp ground Bl/Y 16 2 Y/Bl 41 1 O/Y 17 4 Y/O 42 3 Gn/Y 18 LH HOLD button lamp Y/Gn 43 LG HOLD lamp ground Bn/Y 19 SG Y/Bn 44 L2 (on network) S/Y 20 RR ringer Ring Y/S 45 RT ringer Tip B/V 21 ER V/Bl 46 ET O/V 22 EB V/O 48 EH Gn/V 23 9 (Ring of selected line) V/Gn 48 RR (on network-- Tip of selected line) Bn/V 24 8 V/Bn 49 7 S/V 25 L1 (on network-- grounded V/S 50 N (grounded when off-hook) when on-hook) Bl = Blue O = Orange Gn = Green Br = Brown S = Slate (grey) W = White R = Red Bk = Black Y = Yellow V = Violet Power (actually ground) comes to the phone on the W/O wire, lands on terminal 'IB' then goes to the center position of a SPDT Switchhook contact via a yellow wire. When off hook, this connects to a Brown wire leading to terminal 'N' which feeds the HOLD button first on the center position (of this SPDT momentary switch) feeding further (through the normally-closed contacts) to a yellow wire screwed to terminal 'M'. The five line buttons get their A lead supply from this terminal. On the other side of the HOLD button contacts (the normally-open side) there is a connection available but it is not normally used so it is safely connected back to 'N' thus having no effect when the button is pressed. In the phone I got all this from (a rotary dial phone -- 565HK -- by the way), this is an O/Bk wire. Note that things may have changed a bit since I did this investigation 20 years ago (but not by much) and that some details will be different for TouchTone keypad phones (2565). Each line button is 3PST, two contacts for Tip and Ring, and one for the 'A' (control) lead. When you depress the HOLD button, you interrupt current on the A lead while you *still* have current flowing through the CO loop (Tip and Ring). The 1A, 1A1 or 1A2 KTU (equipment on the wall of the phone closet) senses this condition and throws a relay coil across the phone line to hold it so that you can hang up or select another line. Contacts on this relay and others cause the light to either be steady, flash (when incoming call arrives) or wink (on hold). Because of this mode of operation, the switchhook and the line buttons *must* break their Tip and Ring connections before the A lead, otherwise calls would go on hold every time you hung up or switched lines. Note that the ringer (bell) is on its own pair. You can select which line you want to connect it to, or have it ring whenever a call comes in for any line (if you have the right equipment -- like a local ring current generator) -- the CA (common audible) feature). The other connections are for use with other devices like a speakerphone or a buzzer or the exclusion key or for anything else you may want to do. (See Dave Levenson's message) Additionally, if you unscrew the screw that you can see move up and down when you operate a line button, it makes it momentary contact and will not cause other buttons to pop up. If you further dismantle things, you can remove little pieces of metal that move sideways to cause pressing one button to pop up the others. By doing that you can conceivably tie several lines together to have your own conferencing capability. This requires care since the phone lines will be directly connected together when more than one button is pressed. You have to watch out for maintaining consistent polarity (Tip to Tip and Ring to Ring).