Installation manual

Page 13
Message index display
The Message index display shows the identifiers of messages from a specific
receiver. Unread messages have an “envelope” () mark; locked messages (see Full
message display) have a “key” () mark.
Message identifiers can be expanded to show either the first two lines or the full
message by selecting the desired message and pushing the appropriate softkey.
Messages from another receiver can be displayed using the View softkey, which
cycles through the available sources.
Messages are grouped by time interval. The Show softkey cycles through the set
intervals.
Message summary display
The Message summary display shows the first two lines of each message, selected
by various criteria.
Selection criteria are time, station identity and message type. The Sort by softkey
cycles through these criteria.
Depending on the selection, the “group” is a 4-hour period, a station or a message
type.
The Show softkey controls the total number of messages displayed by suppressing
messages which are older than the selected time frame.
A message can be shown in full by selecting it and pushing the View softkey.
Full message display
Because messages are automatically erased 72 hours after they are received, it is
necessary to take action to retain an important message beyond this time. Displaying
the message and pressing the Lock softkey causes the message to be retained
indefinitely. A locked message is identified by a “key” () mark in the Index display.
A locked message is unlocked by displaying it (in this view) and pressing the Unlock
softkey.
Up to 250 messages can be saved for long term retention; once the limit has been
reached, operating the Lock softkey will not lock any more messages until some are
unlocked again.
Minimising the number of messages displayed
After the NAV-7 has been switched on for a while there will be a large number of
NAVTEX messages stored in memory. These can be quite overwhelming if the user is
looking for particular message categories or an individual message.
Several design features have been incorporated into the NAV-7 to make day to day
operation easier:
• Separate frequency channel pages
• Station filtering