CONE-BEARING 8E7922 - Caterpillar

CAN Communication
Illustration 1 g06183975
Sidecutter Control System
(1) Machine ECM
(2) Propel lever
(3) Sidecutter spray solenoid
(4) Sidecutter down solenoid
(5) Sidecutter up solenoidNote: The blue lines in the illustration indicate an input signal. The red lines indicate an output signal. The red and blue lines indicate two-way communication. Arrows are used to clarify direction of communication.Propel lever (2) communicates sidecutter control switch signals to machine ECM (1) through the CAN lines. The machine ECM monitors signals from the propel lever to determine the desired status of the sidecutter.To prevent data loss in the communication lines, termination resistors are required at the ends of the CAN bus. CAN resistors absorb unwanted noise in the communication system which can result in abnormal machine operation.Differences in materials along the CAN bus can cause data pulses in the bus to reflect back through the bus. This reflection, also known as "jitter", creates unwanted noise in the CAN bus. Jitter in the communication lines between computers can distort the original data signals. This distortion can result in data loss.Data in the CAN bus can also be contaminated with radio frequency interference (RFI). This interference can be caused by various devices which operate on or near the machine. RFI creates noise in the communication lines which can also distort the original data signals and cause data loss.Control Signals
Machine ECM (1) monitors the signals from propel lever (2) to determine the status of the sidecutter control switches. When the machine ECM determines that the sidecutter up switch is pressed, the machine ECM energizes sidecutter up solenoid (5). When the machine ECM determines that the sidecutter down switch is pressed, the machine ECM energizes sidecutter down solenoid (4).Sidecutter parameters
When the parking brake is engaged or the propel system is disabled, the sidecutter system is disabled.When propel lever (2) is moved out of the NEUTRAL position, the sidecutter is automatically raised for 2 seconds. The sidecutter is raised when the machine is reversed. The sidecutter is also raised for 2 seconds when it becomes the trailing sidecutter as determined by propel direction.When the propel system is shifted to roading mode and propel lever (2) is moved out of the NEUTRAL position, the sidecutter cannot be lowered.Sidecutter Spray Control
The sidecutter spray valve is controlled by machine ECM (1). The sidecutter spray system only operates when the machine water spray system is operating.Note: Refer to the water spray section for additional information about the components and controls of the machine spray system.When the sidecutter is lowered, sidecutter spray solenoid (3) is energized. The spray solenoid remains energized when the lower command is stopped.When the sidecutter is raised (manually or automatically), sidecutter spray solenoid (3) is de-energized.