Boom & Platform; Platform Control Enable System; Platform Load Control System; Ground Control Keyswitch System - JLG 600AJ Service And Maintenance Manual

4.1 PLATFORM CONTROL ENABLE SYSTEM

The platform controls make use of a time dependent enable
circuit to limit the time availability of "live" or enabled controls.
To operate any directional function, the footswitch must be
depressed before activation of the function. When the
footswitch is depressed, the controls are enabled, and the
operator has 7 seconds to operate any function.
The controls will remain enabled as long as the operator con-
tinues to use any function and will remain enabled 7 seconds
after the last function has been used. While the controls are
"live", the enabled light will be illuminated in the platform dis-
play panel. When the time limit has been reached, the enabled
light will turn off and the controls will be disabled.
To continue use of the machine the controls must be re-
enabled to start the timer system over again. Do this by releas-
ing all functions, then releasing and re-depressing the
footswitch.

4.2 PLATFORM LOAD CONTROL SYSTEM

The Platform Load Sensing System (LSS) consists of single load
cell and two linkages mounted to the platform rotator and
replaces the platform support on machines that get this instal-
lation. The load cell includes a sealed circuit and is connected
directly to a CAN-based platform control panel within the plat-
form box.
This system compares the capacity to the measured weight in
the platform. When the capacity is exceeded, or when there is
a fault in the system, the platform overload indicator will flash,
the platform alarm will sound at the rate of 5 sec/min and all
platform controls (except auxiliary power) will be disabled. The
ground controls are unaffected.

4.3 GROUND CONTROL KEYSWITCH SYSTEM

The ground control keyswitch is used for selecting the active
control of the machine between the platform or ground con-
trol stations and as another shut off switch for machine power.
The key is removable only in the off position, which allows the
ground control station to have ultimate priority over the plat-
form control.

4.4 FUNCTION SPEED CONTROL SYSTEM

The platform controls for the jib, lift, and main telescope func-
tions are controlled through a common variable speed control
knob. This knob feeds the valve driver of each control circuit
allowing a smooth ramp up, controlled maximum output
speed, and ramp down.
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SECTION 4. BOOM & PLATFORM
Each function has its own personality settings allowing the
characteristics of each function to be modified using the stan-
dard analyzer. Not all functions will respond the same to the
changes in the function speed knob position. The variable
speed control knob when turned counterclockwise and into
the detent position (shown with a snail on the control panel
decal), will place all functions, including proportional func-
tions, in creep.

4.5 SKYGUARD PROTECTION

This machine incorporates a device or system which protects
the user from involuntarily operating the controls. Active con-
figurations may utilize, a bolted-on bar with a sensor (Sky-
Guard), an optical beam sensor (SkyEye), or a magnetic sensor
with a flexible trip mechanism (SkyLine). If the sensor is acti-
vated all functions in use will cease or reverse. Each configura-
tion offers an optional red or blue beacon which flashes when
the sensor is activated. In some markets, a passive system is
available.
SECTION 4 - BOOM & PLATFORM
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