BusinessPhone Communication Platform 7.0
Installation Instruction ASB 150 02 > Boards for ASB 150 02

## BTU-B2 (ROF 157 5121/_)

#### Applies for _indices 4 and 5

- BTU-B2 (ROF 157 5121/4) subequipped
  4 digital trunk lines.
- BTU-B2 (ROF 157 5121/5)
  8 digital trunk lines.

|  | Insert PROM RYS 102 521/ 3 *) |
|  | Insert PROM RYS 102 521/ 4 *) |

*) part of order number: LZY 203 2216/1

The BTU-B2 (Bothway Trunk Unit for ISDN Basic Access=BA) is configurable to provide any mix of up to 8 digital trunk or subscriber connections in the 2B+D format. This amounts to a maximum of 16 simultaneous calls with associated B-channels or data calls.

#### DIP switch settings

##### Position 410-417

These switches control the S- and T-interface termination and the S-interface power feeding for the links 0...7.

Note

At the end of each line a 100 Ohm termination resistor must be installed (e.g. in the last wall outlet).

The switch 1 selects the termination on the transmitter interface and switch 2 selects the termination on the receiver interface. The switches 3 and 4 enable the remote power feeding to ISDN terminals connected to a link. When connected as S-interface the switches 1...4 should be set to ON.

##### Position 418

Note

When selecting as S- or T-interfaces, start by setting the T-interfaces using the switches 4, 3, 2 and 1 in consecutive order, then set the S-interfaces starting with the switches 1, 2, 3 and 4.

#### Connections to the BTU-B/BTU-B2

#### Wall outlet connection

#### Settings of the S-interface

Choose with BMS the configuration of the interface:

- Extended passive bus (default setting) or
- Short passive bus.

#### Ranges on the interface

The BTU-B/BTU-B2 is equipped with the S/T Bus Interface Circuit eXtended (SBCX). This circuit offers the advantage of covering a higher attenuation on cables.

The standard S/T-interface specification considers cables with 6,5 dB attenuation equivalent to about 1000m cable length in single terminal configuration.

Using the S/T Bus Interface Circuit eXtended (SBCX) up to13 dB line attenuation can be covered. The figure below shows the ranges using standard 0.6 mm diameter twisted pair unshielded cables with a capacitive load of max. 30nF per km and the terminal equipment (refer to documentation of the TE) is also equipped with a SBCX or equivalent.

##### Short passive bus

##### Extended passive bus

TE |  | Terminal Equipment

TR |  | Termination Resistor (installed at the end of the interface line. Use outlets with resistor mounted)

|  | Outlet according to IEC 603-7 with termination

|  | Outlet according to IEC 603-7 without termination

Revision: J © Ericsson Enterprise 2005