RCB-F9T - Integration manual
Then if ANT_DETECT is pulled low to indicate no antenna:
$GNTXT,01,01,02,ANTSTATUS=OPEN*35
Then if ANT_DETECT is left floating or it is pulled high to indicate antenna connected:
$GNTXT,01,01,02,ANTSTATUS=OK*25
The antenna open circuit detection is enabled by default in the RCB-F9T.
3.6 Multiple GNSS assistance (MGA)
The u-blox MGA services provide a proprietary implementation of an A-GNSS protocol compatible
with u-blox GNSS receivers. When a client device makes an MGA request, the service responds
with the requested data using UBX protocol messages. These messages are ready for direct
transmission to the receiver communication port without requiring any modification by the MGA
client.
AssistNow Online optionally provides satellite ephemerides, health information and time aiding data
suitable for GNSS receiver systems with direct internet access.
3.6.1 Authorization
The AssistNow Online Service is only available for use by u-blox customers. In order to use the
services, customers will need to obtain an authorization token from u-blox. This token must be
supplied as a parameter whenever a request is made to either service. Please contact your local
technical support or go to https://www.u-blox.com/en/solution/services/assistnow to get more
information and request an authorization token.
3.6.2 Multiple servers
The implementation of the AssistNow Online Service is designed to be highly available and reliable.
Nonetheless, there will be rare occasions when a server is not available (e.g. due to failure or some
form of maintenance activity). In order to protect customers against the impact of such outages,
u-blox runs at least two instances of the AssistNow Online Service on independent machines.
Customers have a choice of requesting assistance data from any of these servers, as all will provide
the same information. However, should one fail for whatever reason, it is highly unlikely that the
other server(s) will also be unavailable. Therefore customers requiring the best possible availability
are recommended to implement a scheme where they direct their requests to a chosen server, but,
if that server fails to respond, have a fallback mechanism to use another server instead.
3.6.3 Preserving information during power-off
The performance of u-blox receivers immediately after they are turned on is enhanced by providing
them with as much useful information as possible. AssistNow services are one way to achieve this,
but retaining information from previous use of the receiver can be just as valuable. All the types of
data delivered by assistance can be retained while the receiver is powered down for use when power
is restored. Obviously the value of this data will diminish as time passes, but in many cases it remains
very useful and can significantly improve time to first fix.
There are several ways in which a u-blox receiver can retain useful data while it is powered down,
including:
•
Battery-backed RAM:
The receiver can be supplied with sufficient power to maintain a small
portion of internal storage, while it is otherwise turned off. This is the best mechanism,
provided that the small amount of electrical power required can be supplied continuously.
V_BCKP is the pin to sustain battery-backed RAM.
UBX-19003747 - R04
3 Receiver functionality
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Early production information
