AS 680/682
Description, Operation and Maintenance Supervisor Operation
ADS−B
5−25Ed. 10.07
5.4.10.1 Trackstore and FOM/PA Restriction
The parameter ’No. of Targets’ (Trackstore) shows the number of targets just found in the output buffer
(see section 5.4.9.2). This parameter is used to check the fill level of the trackstore.
The parameter ’No. of Targets’ (FOM/PA Restriction) is the same like the parameter explained above,
with the exception that only the targets whose Mode−S ID matches an entry in the FOM/PA Restric-
tion table.
The threshold level in percent of the trackstore size (refer to section 5.4.9.2) defines the warning
threshold of the trackstore fill level. If the trackstore threshold level is reached, the status of the Ground
Station changes to WARNING, provided that the BITE test for ‘Trackstore Status’ is enabled and the
’BITE Status’ is retrieved (refer to section 5.4.3).
5.4.10.2 Asterix Information
Sending asterix target reports can be done in two ways: ’Pipeline Mode’ or ’Buffered Mode’. In ’Pipe-
line Mode’ a report is sent as soon as possible after the reception of a valid position or velocity squitter.
In ’Buffered Mode’ the reports are sent in certain interval. The interval can be configured by setting
the parameter ’Send Interval’. If the interval is e.g. set to 4, then a reports (if available) are sent every
4 seconds.
NOTE: The parameter ’Send Interval’ has no effect if pipe line mode is enabled.
The parameter ’Packing’ enables Asterix packing as defined by Eurocontrol. Packing of several re-
ports into one data block is used to reduce network overhead and thus improves efficiency on the
ground communication. In pipeline mode packing is disabled by default.
The text field ’Data Rate’ shows the current rate of sent ASTERIX data in bytes per second. The ’Data
Rate Threshold’ in bytes per second defines the warning threshold for the Asterix data rate.
5.4.10.3 Automatic Data Rate Reduction
This feature will reduce/increase the asterix data output by automatically changing the ’Send Interval’,
if the ’Data Rate’ exceeds/falls below the ’Data Rate Threshold’. ’Min/Max Send Interval’ constraints
can be configured to ensure a certain ’Send Interval’ range in which the ground station will operate.
If the ’Send Interval’ has reached its maximum and the ’Data rate’ still exceeds the ’Data Rate Thresh-
old’, an ADS−B BITE error will be raised.
NOTE: If ’Pipeline Mode’ is enabled this ’Automatic Datat Rate Reduction’ has no effect.
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