Chapter 4 SMART7 with SPAN Operation
SMART7 Installation and Operation User Manual v6
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Saving
The following criteria must be met for valid alignment data to be saved into receiver NVM.
l
The INS solution status must be converged, as indicated by the INS solution convergence flag in the inertial
Extended Solution Status.
l
The system velocity is less than 0.2 m/s.
When these conditions are met, the required information is automatically saved to NVM. If these conditions
cease to be met, the saved alignment data is automatically discarded. If the alignment data is discarded, error
model information is automatically retained as appropriate.
Use at Boot-up
Upon boot, several checks are done to verify that any seed data existing in NVM is appropriate for use. These
checks require a GNSS position to be computed, so an NVM seed will never be injected prior to achieving a
GNSS position. The following criteria must be met in order to use a seed:
l
Seed data from NVM must be valid
l
The system must be stationary
l
The system must not have moved significantly from the seed position: <10 meters position and 10 degrees in
roll and pitch
If a valid error model is present in the seed data from NVM, this will always be used, even if the system is not sta-
tionary or exceeded the movement thresholds.
INJECT Option (Advanced Users Only)
There is an advanced option available to skip the second and third validation steps described in
the boot-up section above. This can be used if GNSS is not available on power-up or if speed to
achieve an alignment is imperative.
This option is for advanced users only. Forcing an injection of an NVM seed without the validation
checks can cause an unstable INS solution if the vehicle has moved.
Apart from injecting the seed at startup without validation, this will also remove some
requirements typically asserted to allow the filter to converge. This will allow the system to run
without GNSS adequately at startup.
Example Usage
Enabling functionality after FRESET:
1. Send the following command.
INSSEED ENABLE VALIDATE
2. Send the following command.
SAVECONFIG
Saving valid INS information:
1. Operate the system as normal, until the filter completes convergence.
2. Bring the system to a complete stop before powering off or resetting.
Using valid INS information on start-up:
