Chapter 3 SPAN Operation
OEM7 SPAN Installation and Operation User Manual v14
98
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:
1. Remain static while initializing.
2. Wait for the system to receive a valid position from GNSS.
3. If valid, alignment data will be injected.
System Indicators
The
INSSEEDSTATUS
log reports the seed injection status for the current power up and information on current
seed validity. Refer the
OEM7 Commands and Logs Reference Manual
for more information about the
INSSEEDSTATUS
log.
The Extended Solution Status field has bits that indicate the Alignment type that occurred and NVM seed injec-
tion status.
Alignment Type: Bits 26-28
These bits indicate how the INS system reached INS_ALIGNMENT_COMPLETE. When the INS system aligns
using saved INS solution data from NVM, bits 26-28 will be set to 101
