Errata Sheet

The following table gives a quick reference to the 3DM-GV7 device limitations and the status.

 

Firmware Version Name Limitation Workaround
1.2.03

 

NMEA Initialization with Invalid Fix

Known bug that can cause Navigation Filter instability if certain conditions occur when using NMEA input.

This will be addressed in an upcoming firmware update. The Navigation Filter can become unstable if the following conditions occur: 

  1. The GNSS receiver initializes with an Invalid Fix Type

  2. The Navigation Filter initializes to Full Navigation Mode during this time

    1. Initial position will be LLH = (0, 0, 0)

  3. The GNSS receiver then obtains a Valid Fix Type at the actual position

  4. The Navigation Filter will then update its position to the actual location of the GNSS receiver

    1. During this update to the actual position, the Navigation Filter may reach high velocities

To ensure such instabilities are not provided as inputs to the user application, apply one of the following work - arounds: 

  1. Initialize the Navigation Filter using GNSS Kinematic Heading Alignment Method

  2. Perform one, or a combination of the following Navigation Filter filter health checks: 

    1. Check the Fix Info (0x91,0x0B) is not FIX_INVALID during Navigation Filter initialization.

    2. Check the LLH Position (0x82,0x01) is not (0, 0, 0) immediately after initialization.

    3. Verify the LLH Position Uncertainty (0x82,0x08) data channel remains below your user specified threshold.

    4. Verify NED Velocity (0x82,0x02) remains within reasonable application specific vehicle velocities.

1.2.03 WMM Omitted

The World Magnetic Model (WMM) is omitted. This may cause large true heading errors when using magnetic heading aiding.

This may be resolved in a future firmware update.

Provide a user-defined magnetic declination angle Magnetic Field Declination Source Control (0x0D, 0x43) appropriate with the application location.

Alternative: Use other Heading Alignment methods for Filter Initialization and Aiding Measurements like True Heading (0x13,0x3A) for External Heading, or GNSS Kinematic Alignment.

1.2.03

Inverted NED Relative Position

The NED Relative Position (0x82,0x42) has a sign error for all components of the vector.

This will be resolved in the next firmware update.

Add a *-1 for each vector element in the message.
1.2.03 NED Relative Position Config Omitted

The Relative Position Configuration (0x0D,0x56) was omitted.

This will be resolved in the next firmware update.

N/A