Technical information
Page 88
Table 8 IEC61162 Transmission interval for periodic sentences
Output
sentence
type
Transmission interval Comments
VDO Once a second Own vessel VDL reports. When a
report is not generated by the AIS
transceiver a ‘dummy’ VDO is
generated in its place.
ALR
(inactive)
Once a minute If no alarms are active, a single
empty ALR sentence is output
ALR
(active)
Once every thirty
seconds
If any alarms are active, an ALR
sentence is output for each active
alarm.
ABK, ACA,
LR1, LR2,
LR3, LRF,
LRI, TXT,
VDM
Only transmitted when
specifically initiated by
an external event