Huawei OptiX PTN 3900 - Page 27

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Installing and Routing cables
Installing and Routing External Clock/Time Cables － Making External Time/Clock
Cables
The OptiX PTN equipment supports 75-ohm and 120-ohm external clock/time interfaces. Select a correct
clock/time cable according to the type of the clock/time interface on the opposite equipment. In the case of the
75-ohm external clock cable, use the bending SMB connector; in the case of the 120-ohm external clock cable,
use the RJ-45 connector.
The OptiX PTN equipment supports the clock bridging cables for converting one or two channels of 75-ohm
clock signals to one channel of 120-ohm clock signals. For a bridge cable, the SMB connector at the 75-ohm
end is made before delivery and the connector at the 120-ohm end needs to be made on site according to the
core connection table.
75-ohm Cable
120-ohm Cable
Core
Blue
Shielding layer
White
PIN
Pin of the CLK/TOD Interfaces on the TN82XCS Board
120-ohm
external clock
External time
(1PPS + time information)
External time
(DCLS)
1
Rx negative of external
clock
Not defined
Not defined
2
Rx positive of external
clock
3
Not defined
RS422 input/output negative of
1PPS signals
RS422 input/output negative of
DCLS time signals
4
Tx negative of external
clock
Grounding
Grounding
5
Tx positive of external
clock
6
Not defined
RS422 input/output positive of
1PPS signals
RS422 input/output positive of
DCLS time signals
7
RS422 input/output negative of
time information
Not defined
8
RS422 input/output positive of
time information
SMB
Interface
75-ohm
external clock
External Time
(1PPS + Time Information)
External Time
(DCLS)
CLK/TOD
(1PPS/DCLS)
Interface for inputting the
external clock
RS422 input/output negative
of 1PPS signals
RS422 input/output
negative of DCLS time
signals
CLK/TOD
(Serial Info.)
Interface for outputting the
external clock
Time information
input/output interface
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