A3lb and a4lb test procedures – ADC Campus-RS Remote User Manual

Page 36

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Loopback Operation

152-402-145-02, Issue 2

30

June 16, 2000

H2TU-R-402

A3LB and A4LB Test Procedures

The H2TU-C can be looped back by sending the Addressable Office Repeater (AOR) LPBK activation code
1111-1111-0001-1110 (FF1E) for at least 5 seconds. This causes the H2TU-R-402 to enter the NLOC state. The
H2TU-C Loopback Time-out (LBTO) setting determines the duration of this loopback unless it is overridden by
the reception of a second identical 16-bit loopup command before the timer expires. When this time-out override
state exists, the only way to loop the H2TU-R-402 down is to issue one of the three loopdown commands listed
in

Table 12

. The automatic time-out mode is restored during subsequent loopback sessions.

Table 12

summarizes the codes required to execute Addressable 3 (A3LB) and Addressable 4 (A4LB) repeater

loopback commands. All code sequences must be present for at least 5 seconds.

Table 12.

Addressable Repeater Loopback Commands (A3LB and A4LB)

Name

Description

Binary Code

(a)

(Hexadecimal Equivalent)

(a) The leftmost bit arrives first in all sequences. The detection algorithm functions reliably with a random 10

-3

Bit Error Ratio (BER)

on the facility. The entire arming and loopback sequence can also be initiated at the remote H2TU-R location.

NLOC

H2TU-R-402 loopup from NI

1111-1111-0001-1110 (FF1E)

CREM

H2TU-R-402 loopup from CI

0011-1111-0001-1110 (3F1E)

NREM

H2TU-R loopup from NI

1111-1111-0000-0010 (FF02)

CLOC

H2TU-R loopup from CI

0011-1111-0000-0010 (3F02)

SMJK

H2TU-R loopup from NI

11000-11000-11000 ...

SMJK

H2TU-R loopup from NI

(b)

(b) Not supported by A4LB.

100000 100000 100000 ...

SMJK

H2TU-R loopup from NI (ESF-DL)

1111-1111-0100-1000 (FF48)

Loopdown

H2TU-C and H2TU-R loopdown from NI OR CI

11100-11100-11100 ...

Loopdown

H2TU-C and H2TU-R loopdown from NI OR CI

100-100-100 ...

Loopdown

H2TU-C and H2TU-R loopdown from NI OR CI (ESF-DL)

1111-1111-0010-0100 (FF24)

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