Cat® Terrain v7 for Grading and Loading Caterpillar

General Information

The onboard software uses a hard-coded setting called Position Error to enable or disable certain functions and features. For example, surface mapping only operates when Position Error is "High Accuracy".

The Position Error can be any of the following values:

• "High Accuracy"

• "Medium Accuracy"

• "Low Accuracy"

• "Autonomous"

Because of the names of the above values, Position Error values are commonly referred to as "position accuracy".

The onboard software then displays the quality of the current GNSS position (the position status) using text in Digital windows and in the "GPS Diagnostics" window.

The position status can be any of the following states:

• "Fixed" (most accurate)

• "Float"

• "DGPS"

• "Autonomous" (least accurate)

• No position

The color representing the accuracy of the GNSS position can be one of the following colors:

• Green

• Yellow

• Magenta

• Red

• Gray

• Orange

Hierarchy of Windows

On a PC that is operating through a virtual private network (VPN), the "Terrain" window will appear above any other windows on the PC.

Illustration 1	g03386808
Icons that cause state changes to occur (1) Proximity Alerts (2) Zone Alerts (3) Speed Alert (4) Speaker button

The drop-down menus close when the icons in Illustration 1 change state or appear on the Status bar.

Illustration 2	g03386824
Icons that do not cause state changes to occur (5) GPS Accuracy (6) Comms (office communications)

The drop-down menus do not close when the icons in Illustration 2 change state or appear on the Status bar.

Background Information

SiteVision Position Error Stats (SVPE Stats) was not commonly enabled as the proprietary General Serial Output Format (GSOF) output until recent requirements. The requirement was to include SVPE Stats in PR2 messages. Sites using Detect or Command must use SVPE Stats.

Reference: To configure the MS Series satellite receiver to output the PR2 message, refer to Systems Operation, M0102735, "Configuration Toolbox User Guide".

Illustration 3	g03417141
Accuracy and position status using "Mode"

Previously the onboard software displayed the accuracy and the position status based on the receiver output "Mode" as shown in Illustration 3 and listed in Table 1. For example, when the "Mode" value was "Fixed", the onboard software displayed a green color and the text "Fixed" appeared in related windows.

Illustration 4	g03417142
SVPE Stats and "Mode" used in v5.0

From v5.0 and onwards, sites may set up receivers to send SVPE Stats and "Mode". The onboard software uses the SVPE Stats to set the color in relevant Digital windows and the "GPS Diagnostics" window. The color is only set while the text displayed in Digital windows is still read directly from the "Mode" value, as shown in Illustration 4.

How Data is Used

The onboard software uses the position accuracy provided by the satellite receiver to define when certain features are enabled or disabled. If the color is not green (in effect, yellow, purple, or red), functions of the onboard software that rely on accurate position stop working.

Functions that stop working when accuracy is not green are:

• The software stops mapping.

• The gauge window does not show elevation.

• Set spot locations (magenta/red) or mark a hazard (red) cannot be set.

The operator uses the color to show the accuracy of the position. Operators work when the color is green, and should follow site guidelines if the color is anything other than green.

Installers or technicians use text, color, and knowledge of two settings in the MCU to give more information about the system. For example, "Fixed" means that the receiver has good satellite coverage, is receiving CMRs, and is generally functioning well.

Using "Mode" Only

Illustration 5	g03417143
Using "Mode" only

In Illustration 5, the site is using the onboard software with the GSOF output "SiteVision Position Error Stats" turned off in the receiver.

The "Mode" value does the following:

• Sets position status ("GPS") to "Fixed"

• Reads the position error ("PE") as "0.004 M"

• Sets position error ("PM") to "High"

• Sets the color to green

Reference: For more information about the options available in Digital windows, refer to the MCU Help, "Options for Digital Windows".

Using "Mode" with SVPE Stats

Illustration 6	g03417146
Using "Mode" with SVPE Stats

In Illustration 6, the site is using Terrain with Detect enabled and the receiver is sending out "SiteVision Position Error Stats" and "Mode". The color, showing the accuracy of the position, is yellow, and the position status is "Fixed".

Illustration 7	g03417147
Using "Mode" with SVPE Stats

The text "Fixed" comes from the receiver output "Mode". "Fixed" means that the receiver has good satellite coverage, is receiving CMRs, and is generally functioning well. For anything other than "Fixed", check satellite coverage, CMRs, and the receiver.

The yellow color comes from a mixture of SVPE Stats and the "GPS High/Medium Error Limit" settings. Yellow means that position accuracy is other than "High Accuracy". Some functions of the onboard software will not work, such as mapping. Elevation will not appear on the gauge window.

The cutoff points between High and Medium accuracy and between Medium and Low accuracy are in the mach_cfg.txt file.

The default values are:

GPS High Error Limit =0.1 m (4.0 inches) - the cutoff point between High and Medium is an SVPE Stat value of 0.1 m

GPS Medium Error Limit =0.8 m (31.5 inches) - the cutoff point between Medium and Low is an SVPE Stat value of 0.8 m

Table 2 lists the SVPE Stat value and the associated quality of position accuracy.

To change the cutoff points between High/Medium and Medium/Low, the installer edits GPS High Error Limit and GPS Medium Error Limit in the MCU.

Example:

GPS High Error Limit =0.05 m

GPS Medium Error Limit =0.8 m

Using Mode Only in Older Receivers

The MS740 series receiver and older receiver series cannot send some values that are required for the messages used between the office and onboard software.

Sites must note the following:

• Sites running Site Awareness must remove MS740 (or older) receivers and use a GNSS receiver which supports "SiteVision Position Error Statistics" in the GSOF Output. Talk to your Cat dealer about which receivers to use.

• Sites running Position Awareness can continue to use old receivers but should note that the machine responds as noted in Table 1.

Menu - Opens the main menu

To view the machine regions on the display, open the main menu and select "Plan" > "Display" > "Machine Regions".