1. GCS 300 System Operation
Application – Level 1

2. Learning Objectives After completing this module you will be able to:
Identify system components
Understand how the system operates
Setup and bench the machine
Utilize the laser receiver for elevation control
Utilize the slope sensor for blade slope control.

3. Theory of operation
Operational theory applies to GCS300-GCS600 configured for a motor grader or dozer
A reference elevation or slope is set, then any changes are sent from the elevation device or slope sensor to the control box. The control box then sends these corrections to a valve module, which in turn sends a correction signal to the valve.
The valve corrects the blade for the changes that were detected
The elevation is derived from a the bench mark. Be it a hub, PK nail, chisel mark, etc…..

4. System components
The main components for GCS 300 are the LR410, EM400 or AS400, CB420, Power module and a Valve module.
LR410
PM400
CB420
EM400
VM4xx
AS400

5. Component descriptions
Each component serves a specific purpose
The LR410 features 360° laser detection and is mounted on the EM400
The EM400 is an electric mast that can be raised and lowered through the control box in the cab. This allows the user to position the LR410 in the center of the laser beam
The AS400 is a slope sensor that controls the actual slope of the blade.

6. Component Description
The CB420 is the control box that is mounted in the cab. It is essentially the “brain box” of the system. It processes the elevation changes from the LR410 and sends it along to the valve module
The VM4xx is the valve module. The valve module receives the corrections from the control box and sends the proper correction signal to the valve (Different VM for different Valve types)
The PM400 is the power module. It receives machine voltage and delivers clean, filtered power to the system.

7. System configuration
GCS 300 is a single point elevation or blade slope only system
Utilizing only one of the following components
Single laser receiver (LR410)
Single point elevation operation
Single slope sensor (AS400)
Blade slope operation OR
Supports single input receiver, receiver and electric mast or blade-slope. It is one or the other, the system does not support a laser receiver and slope sensor combination. Explain that a CB420, VM410 and PM400 are still required for slope only.

8. Component placement LR410 VM410 PM400 CB420 EM400
Explain that the AS400 would be located on the back of the blade if it this was a blade slope only install.

9. Review What are the 6 main components for GCS 300?
Answer: LR410, CB420, AS400, PM400, VM4xx & EM400
What components are required for elevation control?
Answer: LR410, EM400,CB420, PM400 & VM4xx
What components are required for slope control?
Answer: AS400, CB420, PM400 & VM4xx
What component detects the laser beam?
Answer: LR410.

10. CB420 switch layout Right Inc/Dec Switch Left Inc/Dec Switch Display
Auto / Manual LED’s
Elevation Select Switch
*Not used with GCS300
Slope Direction Switch
Power / Setup Switch
Emphasis that the Elevation select switch is not used
Left Rest / Esc Button
Right Rest / OK Button

11. Switch descriptions Power/Setup switch Right Inc/Dec switch
Turns the CB420 on and off
Accesses the Configuration menu when the switch is in the “i” position
Right Inc/Dec switch
Controls the right blade height or slope
Scroll though the menus
Left Inc/Dec switch
Controls the left blade height or slope
Scroll through the menus.

12. Switch descriptions Elevation Select switch Slope Direction switch
Not used with GCS300
Selects which side elevation is automatically or manually controlled. Cross-slope is then displayed on the opposite side. The center position is for dual elevation.
Slope Direction switch
Swaps the angle of the blade when the system is configured with a slope sensor.
Auto / manual LED’s
One set for left side and one set for right side
Lights up green when in automatic mode
Lights up amber when in manual mode

13. Switch descriptions
Right Reset switch (Used when the mast or slope sensor is plugged into the right side of the harness)
Resets the blade’s right bench elevation when “Right” is selected from the menu
Enables the right laser receiver to search for and lock onto the center of the laser beam (EM400 required)
Reads the right slope when in slope control
Accepts changes made in the “Configuration” menu
Enables one step forward in the “Configuration” menu.
Explain that there are two connectors located at the front of the machine. The mast or slope sensor can be installed on either connector. If it installed in the right connector then the right reset switch is used to control the device. Some goes for the left.

14. Switch descriptions
Left Reset button (Used when the mast or slope sensor is plugged into the left side of the harness)
Reads left slope when in slope control
Resets the blades left bench elevation when “left” is selected from the menu
Enables the left laser receiver to search and lock onto the center of the laser beam. (EM400 required)
Rejects changes made in the “Configuration” menu
Enables one step back in the “Configuration” menu.

15. Grade indicators
The left grade indicators are active when a device is plugged into the left side.
Three colored lights indicate whether the blade is in a cut, fill or on grade position.
Down Arrow = Cut
Horizontal line = on grade
Up Arrow = Fill
The right grade indicators are active when a device is plugged into the right side.
Right grade indicators
Left grade indicators

16. Remote switches The auto/manual remote switch can be used to:
Toggle between operator control and GCS 300.
Auto/Manual
Elevation offset will be discussed later during setup and operation

17. Remote switches The offset switch can be used to:
Increase or decrease the elevation or slope by a set amount
Elevation/slope offset
The default offset amount is .10’ for elevation or .10% for slope

18. Review
1. What color are the LED’s when the system is in automatic mode?
Answer: Green
2. What position must the on/off switch be in to access the configuration menu?
Answer: The top position or “i” position
3. What switch controls the blade height or slope?
Answer: The right or left increase/decrease switch. Depends on if the device is plugged into the left or right side
4. What switch starts the mast search?
Answer: The “OK” button (right reset button)
It is very important to emphasize that the operator should never leave the cab when the system is in automatic mode.

19. Review 5. What do the 3 grade lights represent?
Answer: Cut, on grade & fill
6. What are the three functions of the remote switch?
Answer: Switch from manual to auto, elevation offset & slope offset

20. Main display overview Powering up the system
Toggle the power switch to the “I” position
The following screen will be displayed
The icons represent devices that are plugged in to the system.
Guidance Source
Reference elevation
Elevation icon
Remote switch connected
Device connected
The “I” position is the center position of the toggle switch. Reference elevation will be displayed as a percent of slope if they are using a blade slope sensor only.

21. Icon description
The icons are displayed according to what guidance method is being used
Examples:
The guidance source can be an asterisks to represent a laser or a picture of a blade to represent blade slope
The device connected; is a picture of a mast and receiver when using elevation control or it is a picture of slope sensor when using blade slope control
The elevation icon is when operating with a reference elevation or it is displayed as when operating with a cut/fill guidance.
Reference elevation is the typical method of operation.

22. Review 1. What do the five icons represent on the main display?
Answer: Guidance source, elevation icon, device connected, reference elevation & remote switch
2. This icon is displayed when using a slope sensor True or False
Answer: False, this is displayed when using a laser for elevation
3. This icon is displayed when using a reference elevation. True or False
Answer: False, this is displayed when using cut/fill guidance

23. Operating sequence Steps for operation Bench blade
Set reference elevation
Increase or decrease elevation offset as required
Switch into automatic.

24. Benching
The blade must be benched over a point with a known elevation that is relative to the design surface
Level the blade using a spirit level
Place the center of the blade on the benchmark (the center, is the point on the cutting edge that is directly under the center of the mast)
Press the “OK” button. The mast will automatically search for the laser beam. The search will stop once the receiver has found the laser beam
The system is now benched.
The blade must be benched every time the laser is set up. The grade lights will light up on the control box once the receiver has located the beam.
Benching determines the elevation offset between the benchmark and the laser.

25. Set reference elevation
Now that the blade has been benched a reference (benchmark) elevation needs to be entered
Toggle the switch to the “i” position
The following screen will be displayed
Toggle either until “Reference Elevation” is highlighted
Press the “OK” button to enter the reference elevation menu

26. Reference elevation
The system detects what side the mast is connected to
Press “OK”
The current reference elevation is displayed
To set this number to zero, press the “Esc” and “OK” button at the same time.
The reference elevation is usually set to zero. This allows the operator to work back to zero after an elevation offset has been entered.

27. Change the reference elevation
Press the to move the cursor to the right until the digit desired is highlighted
Toggle either to increase or decrease the value of the digit
Repeat these steps until the desired elevation is entered
Press “OK” to save the entered elevation, this also exits to the main menu
Toggle the to the “I” position to return to normal operation.

28. Elevation offset
Now that the system has been benched and a reference elevation has been set, it is ready for use
Move the machine to the work area
Lower the blade to the working surface
If the grade indicators are showing a solid high arrow, then toggle the remote offset switch to enter an elevation offset until the grade indicators flash
This will prevent the blade from driving into the ground when the system is in auto.

29. Operation
Press the auto/manual button on the remote switch to activate automatics
The blade will automatically move to the reference elevation or elevation offset
Increase or decrease the elevation offset until the blade is pushing a workable amount of material
This may take a few passes to perfect.

30. Grading Grading is complete when one of the following occurs:
There is no elevation offset applied to the reference elevation
The on-grade indicators are displayed for the entire pass
The blade is skimming the surface without pushing any material.

31. Review 1. What is the first step in Automatic operation?
Answer: Benching the blade
2. The blade can be positioned at any angle over the benchmark.
True or false
Answer: False, the must be leveled and centered over the benchmark
3. How is the reference elevation set to zero?
Answer: Press the “Esc” & “OK” button simultaneously
4. How is the cursor moved to the right to change a digit in the reference elevation?
Answer: Press the slope direction button

32. Review 5. What button is used to save the entered reference elevation?
Answer: The “Ok” (right reset) button

33. Blade slope
The display will show a percentage of slope rather than a reference elevation
Use the to increase or decrease the amount of slope
Once the correct slope is dialed in, press the auto/manual button on the remote switch to activate automatics
The blade will tilt to the percent of slope that was entered
The operator will control the elevation and material load.
For accurate cross slope the blade must be positioned perpendicular to the direction of travel. Essentially, it is considered straight blading.

34. Field exercises 1. Locate components on machine 2. Power on system
Identify display icons
Confirm system configuration
3. Setup for elevation operation
Bench blade
Set reference elevation
Increase or decrease elevation offset as required
Switch into automatic.

35. Field exercises 4. Setup and operation of slope control
Set percent of slope
Increase or decrease slope offset as required
Switch into automatic
5. Remove and store components
LR410
CB420
Coil cord
Remove and storage of components will cover the nightly removal and storage of all vital components.

36. Learning Objectives You should now be able to:
Identify system components
Understand how the system operates
Setup and bench the machine
Utilize the laser receiver for elevation control
Utilize the slope sensor for blade slope control.

37. Questions? ?

38. Questions Tomorrow? For technical support, contact Trimble:
Phone US:
Phone EMEA:
Phone AP: