Komatsu 730E Operation & Maintenance Manual page 151

OM6008 08/06
Payload Operator Switch
The payload operator switch is used to set, view, and
clear the total load counter and total ton counter. It is
also used to enter the operator ID number (0-9999).
This switch can also be used to view the suspension
pressures and inclinometer. The payload meter oper-
ator switch is located on the dashboard. It is a two-
way momentary switch. The top position is the
SELECT position. The SELECT position is used to
step through the different displays. The lower posi-
tion is the SET position. The SET position is used to
set the operator ID or clear the load and total ton
counters. Normally the inputs from the switch to the
payload meter are open circuit. The switch momen-
tarily connects the circuit to ground.
Speed Input
PLM III uses a speed signal to calculate speed, dis-
tance, and other performance data. This input is criti-
cal to the proper operation of the system. PLM III
receives this signal from the speedometer/operator
display on the dashboard. The same signal displayed
to the operator is used by the system. Distance cal-
culations are made based on the rolling radius of the
tires for a particular truck.
Body-Up Switch
The body-up input signal is received from a magnetic
switch located on the inside of the truck frame, for-
ward the pivot pin of the truck body. This is the same
switch typically used for input to the drive system.
When the body is down, the switch closes and com-
pletes the circuit to 71-control power. 24 VDC indi-
cates the body is down. Open circuit indicates that
the body is up.
Brake Lock Switch
The brake lock is used to lock the rear brakes on the
truck. It is necessary for the accurate calculation of
swingloads during the loading process. Without the
brake lock applied, the payload meter will not calcu-
late swingloads during the loading process. Without
the brake lock, the payload meter will assume that
the truck was loaded using a continuous loader and
flag the haul cycle record. All other functions will be
normal regardless of brake lock usage. The brake
lock input comes from the switch located on the dash
panel. The brake lock switch connects the circuit to
ground. Open circuit indicates brake lock off. Ground
indicates brake lock on.
Payload Meter III - Section 60
Payload Meter
The payload meter is housed in a black aluminum
housing. There is a small window on the face of the
unit. Status and active alarm codes can be viewed
through the window. During normal operation, a two-
digit display flashes 0 back and forth. Active fault
codes will be displayed for two seconds. These
codes are typically viewed using the laptop computer
connected to the serial communications port.
There is one 40-pin connector on the payload meter.
A jack-screw is used to hold the payload meter and
wire harness connector housings together. This
screw requires a 4mm or 5/32 hex wrench. The cor-
rect tightening torque for this screw is 2.8 N·m (25 lb-
in.). Four bolts hold the payload meter housing to its
mounting bracket in the cab.
The circuit board inside the payload meter housing is
made from multi-layer, dual-sided surface-mount
electronics. There are no field serviceable compo-
nents inside. The electronics are designed to with-
stand the harsh operating environment of the mining
industry. Opening the payload meter housing will
result in voiding the warranty.
Communications Ports
The payload meter has two RS232 serial communi-
cations ports and two CAN ports. Connections for the
two serial ports are available inside the payload
meter junction box. The two CAN ports are available
for future electronics systems.
Serial port #1 is used to communicate with the dash-
board display. It is also used to connect to the laptop
computer. The display gauge will remain blank when
the PC is using the serial port. This port initially oper-
ates with serial settings at 9600,8,N,1. These set-
tings change automatically
communications rate when the PC is using the port.
This serial port uses a three-wire hardware connec-
tion.
Serial port #2 is used to communicate to other on-
board electronics like Modular Mining's Dispatch®
system or the scoreboard from Komatsu. This port
uses a three-wire hardware connection. Connections
to this serial port need to be approved by Komatsu.
Several protocol options are available and detailed
technical information is available, depending on
licensing.
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