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Chapter 5 ’Frequently Asked Questions’ — The ASI delay compensation does not lock.
188 Amethyst III DTV Smart Switch
User Manual
The ASI delay compensation does not lock.

What should I do?
If the ASI delay compensation feature does not lock, perform the
following verifications:
 Check the delay compensation maximum bitrate value in the
configuration:
 It should be more than or equal to the input’s real bitrate. If not,
you should get a
buffer overflow alarm.
 It should not be too superior to the input real bitrate (for
instance, it should not be twice the input real bitrate). If so, it can
be difficult for Amethyst III to lock, and you should get an alarm
indicating that the real bitrate is much lower than the configured
maximum bitrate, or that the pattern period is too short.
 Check that the effective period of the synchronization pattern (i.e. the
pattern set in the configuration) is equal to more than twice the
Search
window set in the configuration. If not, you should get an alarm
indicating that the real bitrate is much lower than the configured
maximum bitrate, or that the pattern period is too short.
 If your configuration is a DVB-T SFN stream redundancy, check that
you have selected the
SFN adapter redundancy mode and used
PID 21.

Check that delay compensation is possible: if a device situated earlier
in the chain changed one of the two incoming streams bitrate, or
modified the packets distribution, it is not possible for Amethyst III to
lock.