THOMSON Amethyst III, User Manual, Page: 128 / 306

Chapter 3 ’Web Browser Interface’ — Interface Description
128 Amethyst III DTV Smart Switch
User Manual

Main-spare : the spare input is used only if the main input is
erroneous. As soon as main input becomes safe again, the
switch gets back to it.
When the delay compensation option is enabled, the switch gets
back to the main input only when the delay compensation is locked,
i.e. when it can guarantee that the switch operation will be seamless.
Switch Delay Area
 For minor alarm : duration of minor error the switch must wait before
performing the switch operation, in seconds.

For major alarm : duration of major error the switch must wait before
performing the switch operation, in seconds.
 For critical alarm : duration of critical error the switch must wait before
performing the switch operation, in seconds. If you set the Delay for
critical alarm value, the on air input desynchronization implies
desynchronization in output as well, because the switch is delayed.
Delay Compensation Area
The Delay compensation area is displayed for TS input streams only.
Refer to the Section ’Using the Time Delay and Synchronization
Features’ on page 102 for advice on delay compensation and time delay
configuration.
 Apply time delay : check the box to apply a time delay on one of the
switches inputs. If enabled, the following parameters shall be set:
 Duration : enter the value of the delay to apply, in milliseconds.
 Input to delay : select the input on which you wish to apply the
delay.
 Activate Synchronization : check the box to realign in time the two
streams in input of a switch based on one recurrent element (pattern)
present in both streams. If enabled, the following parameters shall be
set:

Redundancy : select a mode from the drop-down list, among:
- Network : pattern that searches in the stream an occurrence
of a packet occurrence with the PID you defined and a
continuity counter equal to 0.
- SFN adapter : pattern that searches in the stream an
occurrence of a packet with the PID you defined, whatever
the continuity counter. This pattern is suitable for SFN
streams. Indeed, streams are not absolutely identical since
they are generated by two distinct pieces of equipment.
However, the position of synchronization packets for
transmitters (MIP in DVB-T mode / SHIP in DVB-SH mode)
is exactly the same in both streams (but its is not possible
to ensure that their continuity counter are synchronized).
The PID value that should be used for MIP or SHIP is 21.