vances@xenitec.uucp (Vance Shipley) (08/02/89)
In article <telecom-v09i0265m04@vector.dallas.tx.us> levitt@zorro9.fidonet.org (Ken Levitt) writes: >X-TELECOM-Digest: volume 9, issue 265, message 4 of 7 >I know that the colors don't matter as long as I am consistant and my polatity >tester shows all is OK, but I would like to know what the standard is in >color coding. Should the yellow wire go to the terminal marked red or >should the black wire go to the terminal marked red? Telephone circuits are paired as 'tip' and 'ring' wires. On POTS (plain old telephone service) tip is 0 volts and ring is -48 volts (tip is not 'ground' though as it is a blanced line). The pairs must be distinguishable from one another easily so they are colour coded. The colour of the wire indicates whether it is tip or ring. In a quad wire green and black are tip while red and yellow are ring. >[Moderator's Note: Green and red/yellow and black/blue and white... who >can go further? Once I heard a phone man name all twenty five pairs in >a cable and their associated partner.....purple and gray/??? and ???..... >then we get into the slates (stripes)...can anyone reading this name all >twenty five pairs (fifty wires) and the 'proper' color combinations? PT] pair# tip colour ring colour _____ __________ ___________ 1 white blue 2 white orange 3 white green 4 white brown 5 white slate (silver) 6 red blue 7 red orange 8 red green 9 red brown 10 red slate 11 black blue 12 black orange 13 black green 14 black brown 15 black slate 16 yellow blue 17 yellow orange 18 yellow green 19 yellow brown 20 yellow slate 21 violet (purple) blue 22 violet orange 23 violet green 24 violet brown 25 violet slate An individual wire is identified by it's colour and the colour of it's stripe. The main colour determines whether it is tip or ring while the stripe identifies it's pair (i.e. a black wire with a blue stripe is tip of pair 11). In many cables the stripe is missing in which case the pairs are distinguished by the way they are twisted, by pulling back the sheath pairs are more obvious. As you can see there are only 5 tip colors and 5 ring colours (5 x 5 = 25). a 100 pair cable is made up of four of these 25 pair bundles. The first bundle is wrapped by a white/blue binder string, the second by a white/orange binder, the third by a white/green and the fourth by a white/brown. This scheme can be extended infinitum. In article <telecom-v09i0266m05@vector.dallas.tx.us> denbeste@andy.bgsu.edu (William C. DenBesten) writes: >I thought that the order was: > Pair Tip Ring > 1 RED GRN > 2 YEL BLK > 3 BLU WHT, >and that the 1st pair was backwards in a modular connector compared to the >rest. Your polarity is off. Modular connectors reverse the polarity so they make the issue pretty confusing. A modular line cord (that is a properly made _telephone_ line cord) has a flat topology such that when laid on a table the top of both connectors is up. This means that a reversal (polarity wise) takes place. Tip becomes ring on all pairs (the wire is a ribbon in theory). the top of both connectors is up. A 'set' jack (the one inside the telephone) is wired backwards to compensate. >Is this what you were looking for? I culled this from staring at >telephone wiring and looking at advertisements for mod-tap connectors, >so I may be all hosed. The mod-tap connectors got ya! They don't always (read 'often') get the polarity straight from a telephone standards point of view. A standard for using modular connectors with rs-232c is in the works that should clear up much of the mess caused by adhoc "standards" made up by people in need of one! Vance Shipley uucp: ..!{uunet!}watmath!xenitec!vances Linton Technology - SwitchView INTERNET: vances@egvideo.uucp 180 Columbia Street West (soon) vances@xenitec.uucp Waterloo, Ontario CANADA tel: (519)746-4460 N2L 3L3 fax: (519)746-6884