AccuGrade GPS (CD700) GPS Accuracy Mode - Set Caterpillar

GPS Accuracy Mode - Set
1.1. Introduction
2.1. GPS Accuracy Mode Text Items
3.1. Selecting The GPS Accuracy Mode
4.1. Allowing SBAS Positions


As a default, the "GPS Accuracy Mode" dialog is available for all configurations of the AccuGrade System. Depending on the operator configuration settings for your system, some of the options, soft keys, or views that are discussed in this manual may not be accessible on your system.

Use the "GPS Accuracy Mode" dialog in order to set the maximum "GPS error estimate" that is acceptable for your application.

If the "GPS error estimate" exceeds the limits defined for the selected mode, a "Low Accuracy GPS" message is shown on the display.

There are three GPS accuracy modes:

  • Fine

  • Medium

  • Coarse

Your site manager sets the limit for each mode. Your site manager sets each mode to suit the type of work you are doing. (Your site manager can also deactivate the modes.) For example, the limits for fine mode are set for finish trim work. If GPS accuracy is not within the tolerance set for fine mode, do not change into coarse mode in order to continue work on your final trim surface. Instead, do one of the following things:

  • Wait for the GPS accuracy to improve and then continue in Fine mode.

  • Change the GPS Accuracy mode and then continue working on an area that does not require Fine mode GPS accuracy.

  • Change the GPS Accuracy mode and then raise the vertical offset in order to leave the constructed surface high. Return to the area when the GPS accuracy has improved and allows Fine mode operation. This allows you to continue working on the same area of the design and not overcut the final design surface.

Your site manager also sets the auto setting. The setting determines what GPS accuracy is required before automatic controls can be activated. The "GPS Accuracy Mode" dialog displays a "Yes" in the auto column if controls are available.

GPS Accuracy Mode Text Items

Three text items that display the current GPS accuracy level can be displayed on the guidance views:

  • H. GPS Err.

  • V. GPS Err.

  • GPS Acc. Mode

The color of the text item shows whether the current GPS error is within the selected GPS accuracy mode limits:

  • The text item value remains black while the GPS error is less than 90% of the limit defined for the GPS accuracy mode.

  • When the GPS error is approaching the defined limit, the text is blue.

  • If the GPS error exceeds the limit of the GPS accuracy mode, the text is red.

Selecting The GPS Accuracy Mode

If you are using one or more Receivers as position sensors, make sure that the selected GPS accuracy mode is appropriate for the work you are about to do. To check and/or set the GPS accuracy mode, complete the following steps:

  1. From any guidance screen, press the "GPS" soft key.

    Illustration 1g01269801

  1. Press the sixth button from the top on the right of the display in order to swap between the following modes for GPS:

    • Fine

    • Medium

    • Course

  1. Press "OK" to confirm the settings. Press the escape key to exit without saving.

Allowing SBAS Positions

You can change the GPS accuracy mode settings for coarse mode so the GPS receiver accepts SBAS positions.

To allow SBAS positions, complete the following steps:

  1. Press "Edit Modes" from the "GPS" dialog.

    The "GPS Accuracy Mode Settings" dialog appears.

  1. Select "Coarse" Mode.

  1. Enter a value for the "GPS Error Limit".

    For SBAS to work correctly, the value should be greater than the SBAS error of 1 m (3.28 ft) to 2 m (6.56 ft).

  1. Press the next key twice in order to enter the "Allow SBAS Positions".

  1. Use the arrow keys in order to toggle between "Yes" and "No".

    Select "Yes" in order to allow the use of SBAS corrections.

  1. Perform one of the following actions:

    • Press the "OK" key in order to accept the changes and return to the GPS dialog.

    • Press the escape key in order to abandon any changes and return to the GPS dialog. You are asked to confirm that you do not want to save any changes.

  1. Press the escape key in order to exit the guidance view.

    The changes take effect immediately.