1
097-55501-01 Issue 6 – June 2003 45
2
5
3
Description
• Once the phase alignment is as expected, disable the alignment
process by setting CCALIGN to N. This causes the master shelf to
no longer use the CC IN 1 input as a reference, returning to normal
operation using either PRS or DS1 inputs. When the shelf stops
using the CC input, the phase alignment will be maintained. In
other words, the phase of the active timing reference that is used
upon setting CCALIGN to N will not cause a sudden shift in the CC
output phase.
1.6.1.1 Programmable Delay of CC Outputs
For both master and remote shelves, the CC outputs can have a selectable
amount of timing offset applied. The primary purpose for this capability is to
provide a method for compensating time delay associated with long cable
runs.
The capabilities of this feature are:
• Settable in 80 nanosecond increments.
•Range is plus or minus 10 µs. A value of 0 means that no
additional offset is applied. Positive values delay the CC output by
the amount specified. Negative values advance (make earlier in
time) the CC output by the specified amount. To compensate for
cable delay a negative value would be used. For example, suppose
a master shelf is providing a CC output to a remote shelf and the
cable delay has been determined to be 1.9 µs. By setting the
CCDEL value to -1900 (value is set in nanoseconds) the alignment
of the CC signal(s) at the remote shelf will be matched with a non-
delayed CC output signal generated at the master shelf.
• Delay setting is accomplished using the CCDEL keyword. See TL1
Reference for details.
• For convenience, the delay compensation can also be set based on
feet of cable. See CBCOMP keyword in TL1 Reference Manual.
• Each group of 20 ports on each output card group can have a
unique delay value. For example, a CC delay value can be assigned
to the first 20 ports of the "A" output group, a different value to
ports 21-40 of the "A" output group, a different value to ports 1-20
of the "B" group, and so on.
Each individual output port can be selected to have the delay feature
enabled or disabled. For example, it is possible to delay ports 29 and 30 of a
given card group while not delaying any of the other ports in that group. The
CCDENB keyword is used to enable/disable the CC delay capability of
individual output ports. See TL1 Reference for details.
To Next Page
Loading...
Need help?
General
