SECTION 3 - THEORY OF OPERATION - 1230ES
3121222
– JLG Lift –
3-1
SECTION 3. THEORY OF OPERATION - 1230ES
3.1
OVERVIEW
The GROUND MODULE is the master system controller.
Most functions are dispatched and coordinated from this
module, all other system modules handle sub-tasks. All
characterized information (values) are stored into the
ground module (i.e., Personalities, Machine Setups or Cali-
brations). If the ground module is reprogrammed, this
information is lost. The technician should record Personal-
ities and Machine Setups before programming so they can
be restored afterwards. Otherwise, default values can be
used as a starting point to restore previous configuration.
The PLATFORM MODULE reads switch and joystick posi-
tions and relays that information to the GROUND MOD-
ULE. It uses information from the CAN bus for operator
display. It also reports faults pertaining to devices in the
Platform Control Station. In ground mode, the platform
control station may be removed from the vehicle without
affecting operation.
The POWER MODULE controls the main contactor, drive
motors and hydraulic pump motor via commands from
the CAN bus. It also measures current applied to these
loads and input voltage for fault protection and reporting.
For safe operation of the vehicle, the control system will
not allow certain functions under certain conditions.
These are called interlocks. Specific interlocks are dis-
cussed below. The interlocks discussed assume that all
control system devices are functioning properly unless
indicated. Fault conditions will generate DTC’s and addi-
tional interlocks. Some faults only show up at power-up
when the control system performs a self-test. All controls
should be left alone during this test.
Note that the market and model of the machine affects
what personalities and setups are visible by the Analyzer.
The appropriate information is displayed for the given
model and market. The market and model must be set
properly for safe and lawful operation of the machine.
3.2
MODES OF OPERATION
Ground Mode
In Ground Mode, all visual indicators (LED) in the Platform
are off. In fact, the Platform Control Box may be entirely
disconnected as a normal measure (to secure the vehicle),
and this does not prevent Ground Mode operation. When
the machine is powered up in ground mode, only the
functions in the Ground control station are operational,
namely Lift Up and Down. Lift Up and Down is controlled
by a two-position, momentary toggle switch with a center
off position. The switch has the same effect as placing the
joystick in the full up or full down position.
Platform mode
In platform mode the Platform Control Box is enabled. It is
the primary control station for the vehicle. At power-up
indicators applicable to the vehicle configuration illumi-
nate for a lamp check: Battery Discharge Indicator, System
Distress Indicator and Tilt Indicator.
3.3
CAN COMMUNICATIONS
CAN (Controller Area Network) is the type of two-wire dif-
ferential serial communication link used between the plat-
form board, ground board, and the power module for
control of the vehicle. This type of network has matured
since its invention in 1986 and is used extensively in many
kinds of machines.
Two-Wire Differential: The signal meaning is derived from
the difference in voltage between two wires, usually
twisted together in a common "jacket". This jacket can also
contain a shield surrounding the wires inside for noise
protection. Any noise that does penetrate the shield will
affect both wires the same. However, the difference in
voltage stays the same, therefore signal meaning is not
corrupted. This differs from one-wire signals in that one-
wire signals derive the signal meaning from the difference
between the signal wire and system ground wire. The sys-
tem ground is the ground for many signals, as well as
power. Any noise on either wire will change the signal and
may corrupt it.
Serial Communication Link: Modules on the link send mes-
sages digitally, bit by bit along the wires where different
voltage levels represent a "1" or a "0". The 1’s and 0’s are
assembled by the receiver according to the protocol used
to determine the messages meaning. Using serial commu-
nication allows two wires to replace many more. It also
allows use of sensor and switch information in multiple
places without duplicating those sensors and switches.
CAN: On a bus, all modules on the bus are connected to
the same wires. A CAN bus could be represented on a
schematic by a long pair of straight lines with multiple
modules connected to them by short pairs of lines. It has a
termination resistor at both ends of the long lines placed
between the two wires, These resistors are approximately
120 Ohms. On a JLG aerial work platform, this is typically in
the platform and in the chassis. These resistors may be in
the harness or in the module. A complete CAN circuit mea-
sures approximately 60 Ohms between the two wires and
these wires are open to the shield.
Each module on the CAN bus broadcasts its messages
according to a priority assigned to the message. All the
other modules will receive the message and determine if it
is important to them. Typical message traffic is 300 - 500
messages per second. The high bus speed allow all mod-
ules to be constantly updated around 20 times per sec-
ond. A CAN network also has error detection and handling
for robust communications.
Summary of Contents for 1230ES
Page 1: ...AS NZS Service and Maintenance Manual Model s 1230ES P N 3121222 June 22 2017 ...
Page 2: ...NOTES ...
Page 24: ...SECTION 1 MACHINE SPECIFICATIONS 1 12 JLG Lift 3121222 NOTES ...
Page 32: ...SECTION 2 GENERAL SERVICE INFORMATION 2 8 JLG Lift 3121222 NOTES ...
Page 78: ...SECTION 4 BASE COMPONENTS 4 40 JLG Lift 3121222 NOTES ...
Page 104: ...SECTION 5 CONTROL COMPONENTS 5 26 JLG Lift 3121222 NOTES ...
Page 158: ...SECTION 8 DIAGNOSTIC TROUBLE CODES 8 22 JLG Lift 3121222 NOTES ...
Page 198: ...SECTION 9 GENERAL ELECTRICAL INFORMATION SCHEMATICS 9 40 JLG Lift 3121222 ...
Page 199: ...SECTION 9 GENERAL ELECTRICAL INFORMATION SCHEMATICS 3121222 JLG Lift 9 41 ...
Page 200: ...SECTION 9 GENERAL ELECTRICAL INFORMATION SCHEMATICS 9 42 JLG Lift 3121222 ...
Page 202: ...SECTION 9 GENERAL ELECTRICAL INFORMATION SCHEMATICS 9 44 JLG Lift 3121222 NOTES ...