R60 Station
R60 User Manual
Document Number
Version
Date
7000 120-019
A1
2022-08-10
Page 89 (98)
10
NMEA SENTENCES
The R60 uses standard NMEA sentences as defined in Ref [5] to communicate. In
addition to the standardised sentences, a number of Saab proprietary sentences are
also used.
During normal operation both standard and proprietary sentences are used and will be
output from the R60. Saab proprietary sentences start with $PSTT and are thus easily
identified.
10.1
Channel management
The standardized ACA sentence is used to define channel management zones. The R60
can handle a total of 8 zones which are identified via the sequence number field of the
ACA sentence (0-7).
Each zone can be turned on or off by using the in-use flag field. To enable the zone for
transmission in message 22, the in-use flag field is set to ‘1’. To disable it the in use flag
field is set to ‘0’.
The preferred method to setup channel management is to use the Channel Management
page (a sub-page of the Configure main category) in the R60 web GUI as described in
section 6.9 of this document.
10.2
Multiple group assignment areas
The standardized AGA sentence is used to define a group assignment area. An R60 Base
Station supports multiple such areas. One group assignment area is available for each
mobile
3
type (resulting in a total of 16 areas). It is possible to have the R60 handle only a
single group assignment area, which is the behaviour when using R40 Mk III legacy mode.
When multiple areas are supported, each area can be enabled or disabled by using the
coordinate settings. All coordinates of an area must be valid to enable it. Setting any of
the latitudes to 91 degrees north, or longitudes to 181 degrees east, disables the area.
The preferred method to setup channel management is by using the Group Assignment
page (a sub-page of the Configure main category) page as described in this document in
section 6.10.
10.3
Data link messages
VDM sentences can be used to send arbitrary data from the base station. When doing
so the R60 modifies certain messages in order to preserve VDL link integrity, in
accordance with Ref [5]. Only position messages and messages containing slot offsets
are modified.
3
See list of Mobile types in Table 6-8, section 6.10
