T1

Loop Back Testing

Refer to Figure 8-3and the CSU manufacturer’s Installation and Maintenance manual for information on CSU Local/Network Loopback Tests.

RDTU

RDTU Amphenol Pin Nos.

RDTU TX Open

NDTU Cable

MITEL Chip

 

 

P1/P26 Transmit

P4

CSU

 

P2/P27 Receive

MM8976B

 

Network

Interface

Unit (NIU)

Network

2581

Top LED

T1

 

LEDS ON RDTU PCB

 

 

 

 

 

 

0

Busy

ON Steady

 

 

 

 

0

FALM

ON

OFF

OFF

OFF

ON

Continue to Cycle when

 

 

 

 

 

 

 

0

FMALM

OFF

ON

OFF

OFF

OFF

P4 is in ON Position

0

YALM

OFF

OFF

ON

OFF

OFF

 

0

BALM

OFF

OFF

OFF

ON

OFF

 

Bottom LED

 

T1

T2

T3

T4

T5

T6 T = About 1/2 Second

 

 

 

 

 

 

 

 

0

Primary SYNC

 

ON or OFF, Steady

 

 

 

 

0

Secondary SYNC

 

ON or OFF, Steady

 

 

 

 

1673

Figure 8-12 Network/CSU/RDTU Span Test

Notes

Local loop back and network loop back test cannot be performed simultaneously.

CSU local/network loop back is a function of the CSU, not all CSUs provide this function – see CSU I&M documentation for CSU loop back test procedures.

Test RDTU Lines

After loop back testing is complete and synchronized with the far end T1 circuit, perform test calls on all RDTU lines.

Strata CTX I&M 06/04

8-21

Page 329
Image 329
Toshiba CTX28 manual Test Rdtu Lines