PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 237

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

6.7.2
The typical procedure for closing and opening a complete loop-back is demonstrated in
the examples below.
Complete Loop-Back in EOC Auto Mode
<–––––
(–––––> C/I AI
<–––––
<–––––
<–––––
–––––>
<–––––
In the above example the LT is operated in EOC Auto mode.
Semiconductor Group
NT
C/I AR
C/I AI
C/I AIL
MON-0
LBBD
MON-8
LBBD
MON-0 RTN (FF
Examples for Complete Loop-Back #2 Control
(1000
(1100
(1100
(1110
(50
(F1
H
H
H
)
)
)
B
B
B
B
) C/I UAI
)
) C/I AI
)
LT
C/I AR
MON-0
LBBD
MON-0
LBBD
MON-0
RTN
MON-0
RTN
237
(1000
(1100
(50
(50
(FF
(FF
(0111
H
H
H
H
)
)
)
)
B
B
B
) <––––– ; U-interface is activated
) –––––> ;
) –––––> ; terminal confirmation)
<––––– ; Close complete loop (EOC)
–––––> ; Receive acknowledgment
<––––– ; Open all loop-backs
–––––> ; Receive acknowledgment
;
; or with
; Request for downstream
;
;
;
;
; All loop-backs opened
without terminal
confirmation
device to close complete
loop-back
If downstream device can’t
close, loop is closed in IEC
Data Sheet 01.99
Programming
PEB 2091
PEF 2091