Toshiba CTX28 manual Connecting Rbsu to Network Side TE-Mode

ISDN Interfaces

RBSU/RBSS Interface Units

Strata CTX BRI Circuit EMC Ferrite Core Requirement

To ensure that the Strata CTX BRI circuit meets the EMC requirements, it is necessary to run all wire connecting ISDN BRI circuits (TE, LT mode and NT mode) through a Ferrite core. Use Toshiba part number, FER-CORE-ISDN, to order the ferrite core. It is not shipped automatically with the BRI circuit cards, it must be grounded separately. Figure 7-16shows how to dress the wiring through the Ferrite core.

RBSU or RBUU

RBSS or RBUS

ISDN Interfaces

ISDN

PRI Jack

CAT 3, 4, or 5 Cable

4697	Tie
	Wrap

Ferrite Core

FER-CORE-ISDN

One Turn

Note: Locate the Ferrite core as close as possible to the BRI modular jack.

Figure 7-16 BRI Circuit Ferrite Core Installation

Connecting RBSU to Network Side (TE-Mode)

The RBSU only, not the RBSS, circuits can be connected to the network side of a BRI line. The RBSU circuits must be configured in the TE-mode (refer to option switches in Table 7-8on page 7-17).

In the U.S., the BRI line from the ISDN service provider is a two-wire U-type BRI line. This line connects to the RBSU TE circuit via a customer-provided NT1 as shown in Figure 7-17. The NT1 is necessary to convert the network BRI, two-wire, U interface to the RBSU BRI, four-wire, T interface. The NT1 must be UL listed (U.S.) or CSA certified (Canada).

The NT1 is powered by local AC power via an AC adapter supplied with the NT1. The connection between the NT1 and the RBSU TE circuit is a point-to-point connection, so the NT1 can connect to only one RBSU BRI TE circuit.

A100-ohm Terminating Resistor (TR) is required on each end of the point-to-point connection. The TR must be switched into the RBSU TE circuit (refer to option switches in Table 7-11 on page 7-22and Table 7-8 on page 7-17) and into the NT1 device.

Strata CTX I&M 06/04 7-23