JLG X23J - X700AJ Service Manual - Manual (Page 495)

SECTION 6 - JLG CONTROL SYSTEM
6-6 – JLG Lift – 3121448
6.3 CANBUS COMMUNICATIONS
The electrical system works with a CAN BUS system,
where:
CAN = Control Area Network
BUS = Channels for peripherals
CANbus: CAN (Control Area Network) is a two wire differ-
ential serial link between the, Ground Module ECM1-2; the
Remote Control (Or receiver); the LSS ECM3, the working
area Module ECM4; the Cylinders position sensors and
the Rham Modem Module providing bi-directional com-
munications.
Two-wire: One wire (White; Black or Black with numbers)
is driven high (5v) and the other low (Gray; Brown or Black
with number) (0v) to send a signal; both wires”float” (2.5v)
when no signal is being sent.
Differential: Any electrical line noise can affect the high or
The low wires but never both, so communications is not
corrupted.
Serial Link: Messages are being sent bit by bit along the
wires; the high bus speeds allow all modules to be con-
stantly updated around 20 times per second. Typical traf-
fic is 300 - 500 messages per second.
A complete CANbus circuit is approximately 60 ohms,
Each individual circuit from the modules is approximately
120 ohms.
The GROUND MODULE ECM1-2 is the master system
controller.
Most functions are dispatched and coordinated from this
module, all other system modules; Remote Control (Or
receiver); LSS ECM3, working area Module ECM4; Cylin-
ders position sensors; Rham Modem.
Fundamental characterized information (values) are
stored into the ground module ECM 1-2 (i.e., Personalities
or Calibrations), while on the LSS ECM3 the basket load
setting and on the Module ECM4 the working area.
Lift, Tele, Swing & Drive:
The GROUND MODULE ECM1-2 stores default values,
handles interlocks and calibration information.
Lift, Telescope Swing and Drive commands are depen-
dent upon interlocks through out the machine that
enables the power supply of the ON -OFF proportional
coils after verification of the safety conditions by handles
interlocks.
The safety control functioning ECM1 can be by - passed
by the key selector switch (spring return) “safety device
by-pass key”.
The circuit board ECM1 stores any by-pass event by date,
time and duration of the “safety device by-pass key”
action.
Dual capacity and Load Sensing System
The module ECM3 control the max load on the basket and
two different working area; jib open max 120 kg - jib
closed max 200 kg.
When the maximum accepted load is reached, an icon
appears on the remote control display.
Restricted Work Area Position
On the X23J and the X700AJ the working area Module
ECM4, control if at least one of the outriggers is set in the
restricted area position. The platform/remote control box
LCD will display the symbol for restricted area operation
which is always visible during the use of the machine in
this set up.