ALTERNATOR GP-CHARGING 1860234 - Caterpillar

CAN Communication
Engine ECM (14), machine ECM (7) and display unit (9) communicate through a controller area network (CAN). In order to prevent data loss in the communication lines, termination resistors are required at the ends of the CAN bus. CAN resistor (13) acts as the termination resistor for engine ECM (14). Machine ECM (7) and display unit (9) have internal resistors. The 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. The 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 a number of 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.Determination of Vibratory System Status
Machine ECM (7) monitors the input signal at terminal "C1-6" in order to set the status of the vibratory system. Throttle control switch (8) and vibratory control switch (5) control the power supply circuit to terminal "C1-6" of the machine ECM. When the circuit at this terminal is open, the machine ECM sets the vibratory status to "off". When machine ECM (7) reads a voltage input at terminal "C1-6", the ECM sets the vibratory status to "on". The following conditions must be met for power to transfer to terminal "C1-6" of the machine ECM:
Throttle control switch (8) must be in the HIGH IDLE position.
Vibratory control switch (11) must be closed.When machine ECM (7) has set the vibratory status to "on", the ECM evaluates the following additional input parameters:
Engine speed
Vibratory mode
Vibratory amplitude
Vibratory frequency (Variable frequency system)Determination of Engine Speed
Machine ECM (7) receives engine speed data from engine ECM (14) through the CAN. Engine speed must be greater than 1600 rpm for the machine ECM to operate the vibratory system.Determination of Vibratory Mode
Machine ECM (7) monitors the input from vibratory mode switch (18) during operation. The vibratory mode switch is a double pole switch with two positions. One of the poles of the switch controls the input signal to terminal "C2-5" of the machine ECM. The other pole controls the indicator lights in the switch. When vibratory mode switch (18) is in the MANUAL position, the circuit across contact "1" and contact "2" is closed. In this switch position the circuit across contact "4" and contact "5" is also closed. Under these conditions, machine ECM (7) reads a ground signal at terminal "C2-5", and the manual indicator in the switch is illuminated. A ground signal at this terminal prompts the machine ECM to set the vibratory mode to "manual".When vibratory mode switch (18) is in the AUTOMATIC position, the circuit across contact "2" and contact