Response of h2tu-c – ADC HiGain H2TU-C-319 List 4E User Manual
Page 35
LTPH-UM-1049-02, Issue 2
Provisioning
H2TU-C-319 List 4E
January 9, 2002
27
a successful loopdown is reported; otherwise, a failed loopdown is reported. The loop-down can also be initiated
by depressing the H2TU-R loopback control button or by any of the standard 3-in-5 loop-down commands. The
implemented detection/release loopback algorithm functions properly in the presence of a 10
-3
bit error rate.
Since the FT1 mode is a combination of both the full T1 and the latching loopback modes, all codes are always
active. Therefore, if a loopback is initiated by a latching sequence, it can be looped down by either a latching or
generic loopback and vice versa. All loopback commands are completely symmetric in the FT1 mode.
If the latching sequence shown in
is interrupted for more than 20 minutes, the detection is
cleared, and the H2TU-C reverts back to its initial state where it searches for the initial sequence 1.
After a successful latching sequence terminates in a latched loopback state, this state remains until the Disable
command is detected, or until the LBTO option of NONE, 20, 60, or 120 minutes has expired, whichever occurs
first.
The unframed AIS pattern that is normally sent toward the network for a CI LOS fault condition must be replaced
by the new patterns listed in
when the FT1 loopback option is selected.
Table 13.
Response of H2TU-C-319 List 4E and H2TU-R to LOS and AIS
H2TU-C Output Pattern
Case
FT1
Option
H2TU-C
Input
Framing
Payload
FDL
H2TU-R
Input
H2TU-R
Output
Status Screen
Front-Panel
Display
1
ENA
SF
SF
01111110
N/A
LOS/AIS
01111110
UNFR
RCV
RLOS/RAIS
XMT IDLE
ALRM
RLOS/RAIS
2
ENA
ESF
ESF
01111110
X
(a)
LOS/AIS
01111110
UNFR
RCV
RLOS/RAIS
XMT IDLE
ALRM
RLOS/RAIS
3
ENA
LOS/AIS
SF
01111110
N/A
LOS/AIS
01111110
UNFR
RCV
RLOS/RAIS
XMT IDLE
ALRM
RLOS/RAIS
4
ENA
LOS/AIS
SF
PL
X
(a)
SF/PL
AIS
RCV LLOS/LAIS
ALRM
LLOS/LAIS
5
ENA
LOS/AIS
ESF
PL
X
(a)
ESF/PL
AIS
RCV LLOS/LAIS
ALRM
LLOS/LAIS
(a)
“
Don’t care” bit