POWER DOWN STATE

Power consumption of most functions is reduced;

module interface is not active; C/I messages can-

not be exchanged.

ACTIVATION DEACTIVATION

The ACTIVATION procedure consists of three

steps: AWAKE, SYNCHRONIZE and CONNECT

THROUGH.

Activation times are (max):

COLDSTART 1 sec

WARMSTART 170 msec

The DEACTIVATION procedure consists of two

steps: line DEACTIVATION and POWER DOWN.

Deactivation time is (typ) 4 ms.

OSCILLATOR

Oscillators of 15.36 MHz are required. When in

NT a tollerances of +/-30 ppm is allowed, it is ad-

visable to use in LT a tollerances of +/-20 ppm.

LINE RANGE

The LINE RANGE depends on the cable section.

Typically:

up to 4.2Km with 0.4mm cable

- 5.5Km - 0.5mm -

- 8.0Km - 0.6mm -

Assumed noise level for such performances is

10uV/SQRT(Hz) on a 200KHz bandwidth.

LT CLOCK JITTER

The

phase

jitter

between

Master

Clock

(15.36MHz)

and

interface

clock

(4.096MHz)

should not exceed 50ns.

LT mode COMMANDS (DIN)

ACT

1 0 0 0

Activate.

UIC is set in power-up state, executing the complete activation of Layer 1. The

transparent channel transmission is enabled.

AL

1 0 0 1

Analog Loop.

The analog transmitter output is looped back to the receiver input which is

disconnected from UK0 interface. A pseudo wake-up procedure is executed.

L2

1 0 1 0

Loop 2.

Command to close Loop 2 in NT.

LTD

0 0 1 1

Line Transmission Disabled.

UIC stops transmitting signals on the line and is powered down.

DEAC

0 0 0 0

Deactivate.

Request to deactivate UK0.

RES

1 1 0 1

Reset.

Reset the UIC to the initial state.

SSP

0 1 0 1

Send Single Pulse.

The UIC transmits single pulse at 1 ms time intervals with alternate polarity.

L4

1 0 1 1

Repeter loop

LT mode INDICATION (DOUT)

ACT

1 0 0 0

Activation running.

UIC is powered-up and the activation procedure is running.

RDS

0 1 1 1

Running Digital Sum.

Given during activation procedure. The receiver has reached synchronization.

CT

1 1 0 0

Connection Through.

Layer 1 activation procedure has been completed. B and D channels are

transparently connected.

DEAC

0 0 0 1

Deactivation running.

UIC is deactivating in response of a DEAC, RES or LTD command.

DC

1 1 1 1

Deactivation confirmation.

UIC has completed the deactivation procedure.

RSYN

0 1 0 0

Resynchronization.

The receiver has lost framing and is attempting to resynchronize.

HI

0 0 1 1

High Impedance.

When pin PFOFF is HIGH indication HI is output and UIC starts transmitting

INFO U0. Normally used to indicate that remote feeding has been switched off.

STU2071

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