Canbus Communications; To Connect The Jlg Control System Analyzer; Using The Analyzer - JLG 740A Service And Maintenance Manual

SECTION 6 - JLG CONTROL SYSTEM
6.2

CANBUS COMMUNICATIONS

CANbus: CAN (Control Area Network) is a two wire differ-
ential serial link between the Platform Module and Ground
Module providing bi-directional communications.
Two-wire: One wire (red) is driven high (5v) and the other
low (black) (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 speed 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,
which can be verified at the "T" fitting inside the ground
station. Each individual circuit from the modules is
approximately 120 ohms.
6.3 TO CONNECT THE JLG CONTROL
SYSTEM ANALYZER
1. Connect the four pin end of the cable supplied with
the analyzer, to the controller module located in the
platform box or at the controller module in the
ground control box and connect the remaining end
of the cable to the analyzer.
NOTE: The cable has a four pin connector at each end of
the cable; the cable cannot be connected back-
wards.
2. Power up the Control System by turning the lower
key to the platform or ground position and pulling
both emergency stop buttons on.
6-14
6.4

USING THE ANALYZER

With the machine power on and the analyzer connected
properly, the analyzer will display the following:
HELP:
PRESS ENTER
At this point, using the RIGHT and LEFT arrow keys, you
can move between the top level menu items. To select a
displayed menu item, press ENTER. To cancel a selected
menu item, press ESC.; then you will be able to scroll
using the right and left arrow keys to select a different
menu item.
– JLG Lift – 3121160