AT&T 555-230-894 manual Install Multipoint Adapters, BR851-B Adapter T-Adapter

Install Multipoint Adapters

Figure Notes:

1.Part terminating resistor block

2.2-pair cross-connect

3.Row “A”

4.Row “B”

5.Row “C”

6.Basic multipoint option

7.2-pair cross-connect

8.Part of 4-pair blue field

9.4-pair horizontal cables

10.To Integrated Services Digital Network (ISDN) S/T-interface terminals

11.White or purple field

12.From Integrated Services Digital Network (ISDN) T-interface circuit (2-pair)

Figure 9-19. Typical Installation of Terminating Resistor Block (110RA1-12)

Two terminal Basic Multipoint applications are accommodated by connecting row B (output) to the second terminal common to the multipoint circuit.

Install Multipoint Adapters

Multipoint Adapters are used to provide signal fan-out of the T-interface. Fan-out can be performed at the work station by the BR851-B or the 367A. These adapters support more than one Integrated Services Digital Network (ISDN) terminal per horizontal 4-pair D-Inside Wire (DIW). To support multiple horizontal runs, fan-out must be performed in the satellite closet by a cross-connected field with multiple common rows (or blades).

The 110RA1-12 provides fan-out for two horizontal runs and also contains the 100 Ohm terminating resistor. This can be used for Basic Multipoint or point-to- point with terminating resistor in the closet. Other fan-out blocks include the 110AB1-025M and the 110AB1-050M.

BR851-B Adapter (T-Adapter)

The BR851-B supports two terminals on one multipoint Basic Rate Interface (BRI) at the workstation. It is a T-shaped device used to fan-out transmission and power. The BR851-B is an 8-position device with a single plug and two jacks. Figure 9-20shows the wiring diagram of the BR851-B.

Issue 1 September 1995 9-43