THOMSON Amethyst III, User Manual, Page: 135 / 306

Chapter 3 ’Web Browser Interface’ — Interface Description
Amethyst III DTV Smart Switch 135
User Manual
The severity is indicated by dedicated icons.
Table 3-8. Tests severity
Severity Icon Consequence
Critical Switch
Major Switch
Minor Switch
Warning Monitoring
The severity is present in several parts of the GUI: configuration, active
alarms, closed alarms, switch state (in switch state view, icons give
global status of each input).
Persistence
Persistence may be configured for some tests to avoid switching to occur
much more frequently than required, as example the Continuity counter
error which is a punctual error that can appear very frequently and
disappear immediately.
Persistence Notion
To explain the notion of persistence, let us consider the example of
continuity counter errors.
Continuity counter error is a punctual error that can appear very
frequently and disappear immediately. When faced with this type of
error, switching may occur much more frequently than required.
To avoid this, we have added the notion of persistence:
 An alarm is raised only if there is a significant number of error
occurrences.

An alarm remains raised for a given amount of time after the error
occurrences.
Persistence may be configured using the following parameters:
 Persistence duration : duration of a "rolling period". The number of
error occurrences is permanently computed in this time window, and
compared to predefined thresholds.
 Upper threshold : if the number of errors is greater than or equal to this
value over the rolling period, alarm is raised. Threshold shall be 1 or
greater.
 Lower threshold : if the number of errors is lower than or equal to this
value over the sliding period, alarm disappears. Threshold shall be 0
or greater, and shall be strictly lower than the associated upper
threshold.