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19 — X.21 and V.35 DCMs
2902 MainStreet Technical Practices
19-11
May 2002 90-2906-01
Type of synchronous clocking
For both the X.21 and V.35 DCMs, when you configure the type of synchronous
clocking, you are configuring the effect that the 2902 MainStreet system has on
clocks passing through it. The type can be set:
•
to the timing of the 2902 MainStreet system (LOCKED) (default)
•
to be passed through transparently (INDEPNT)
If the clocking for a circuit is independent, the clocking information is embedded in
the signaling bit of an HCM frame and passed through transparently. Deviations of
up to 50 b/s relative to the nominal rate can be accommodated.
For more information, ask your supplier representative for Configuration Note
NCN305, entitled “Data Interface Clocking”.
Receive clock
The receive clock on X.21 DCMs with revision 2 DRAGA can be inverted. The
default is no inversion. Receive clock inversion can compensate for a phase shift
between the transmit clock and receive data signals, if it occurs.
If you are experiencing high bit error rates (sometimes due to a combination of
interface speed, cable length and DCM clocking configurations) try inverting the
receive clock (RX_INV).
Procedure 19-8 To configure clocking
The RX_INV/NO_RX_INV softkey applies to the X.21 circuits only.
where
pp
is 1 or 9, and
c
is 1
* Default
Note —
The INTERNAL softkey is not available if transparent rate
adaption is selected.
RX_INV
/NO_RX_INV*
INTERNAL EXTERNAL
LOCKED*
/INDEPNT
SLAVE*
CONFIG — CIRCUIT — <
pp-c
>
↵
— FUNCTION — CLOCKING
SK000506
Содержание MainStreet 2902
Страница 1: ...2902 MainStreet Network Termination Unit Release 1 0 H T E C H N I C A L P R A C T I C E S ...
Страница 40: ...3 Mounting the unit 3 8 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 50: ...4 Ground and power connections 4 10 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 68: ...6 Connecting to the network 6 4 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 90: ...7 Connecting to data devices 7 22 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 108: ...10 Node management 10 10 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 150: ...14 CPSS 14 6 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 168: ...16 E1 circuit operating parameters 16 4 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 218: ...20 Codirectional DCM 20 6 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 234: ...22 HCM rate adaption 22 10 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 246: ...23 Cross connecting circuits 23 12 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 254: ...24 Visual indicators 24 8 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 266: ...25 Alarms 25 12 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 278: ...26 System diagnostics 26 12 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 298: ...27 Loopbacks 27 20 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 332: ...Glossary GL 8 2902 MainStreet Technical Practices 90 2906 01 May 2002 ...
Страница 343: ......
Страница 344: ... 2002 Alcatel All rights reserved 90 2906 01 95 1820 01 00 C ...