216 isdn st bus nt1 star up to eight terminals on the

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21.6 ISDN S/T Bus (NT1 Star) Up to eight terminals on the S/T bus which are wired from a central NT1 and can be up to 1km in length each. 21.7 ISDN S/T Bus Pinout The S/T bus connects the NT1 with the terminal equipment. See section 10.0 for plug identification and pin numbering. Note, if power is not required an RJ11 (6-pin) plug could be used. Some NT1 devices have a switch to turn off power if it is not required by the terminal equipment. For safety reasons the power should not be put on the S/T bus if it is not required. Typically, ISDN PC cards do not require power from the S/T bus, but ISDN telephones do require power from the S/T bus. Check your vendor equipment specifications carefully. RJ45 Plug for ISDN S/T bus ========================== 1 N/C 2 N/C 3 White/Green ..... Receive + 4 Blue ............ Transmit+ 5 White/Blue ...... Transmit- 6 Green ........... Receive - 7 White/Brown ..... -48VDC (option) 8 Brown ........... -48VDC Return (option) 21.8 ISDN Cabling Guidelines The North American ISDN Users Forum (NIUF) has produced a document titled _ISDN Wiring and Powering Guidelines_ NIUF #433-94 which describes residence and small business ISDN cabling. See section 30.0 for the NIUF document ordering address. ------------------------------ Subject: 22.0 Testing Unshielded Twisted Pair Cables 22.1 Testing UTP Introduction Many of the problems encountered in UTP cable plants are a result of miswired patch cables, jacks and crossconnects. Horizontal and riser distribution cables and patch cables are wired straight through end-to-end -- pin 1 at one end should be connected to pin 1 at the other. (Crossover patch cables are an exception, as described later). Normally, jacks and crossconnects are designed so that the installer always punches down the cable pairs in a standard order, from left to right: pair 1 (Blue), pair 2 (Orange), pair 3 (Green) and pair 4 (Brown). The white striped lead is usually punched down first, followed by the solid color. The jack's internal wiring connects each pair to the correct pins, according to the assignment scheme for which the jack is designed: EIA-568A, 568B, USOC or whatever. (One source of problems is an installation in which USOC jacks are mixed with EIA-568A or 568B. Everything appears to be punched down correctly, but some cables work and others do not).
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Data Communications Cabling FAQ Page 14 of 19 09/21/1999 22.2 Wiremap Tests Wiremap tests will check all lines in the cable for all of the following errors: Open: Lack of continuity between pins at both ends of the cable. Short: Two or more lines short-circuited together. Crossed pair: A pair is connected to different pins at each end (example: pair 1 is connected to pins 4&5 at one end, and pins 1&2 at the other). Reversed pair: The two lines in a pair are connected to opposite pins at each end of the cable (example: the line on pin 1 is connected to pin 2 at the other end, the line on pin 2 is connected to line 1). Also called a polarity reversal or tip-and-ring reversal.
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  • Spring '12
  • BryanJensen
  • Twisted pair

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