Version 2.0.3 Preliminary Documentation – May be Subject to Change 36-36
CAN Wiring
The CAN port is electrically isolated from all other circuits. The isolation is SELV rated with
respect to product safety requirements. Refer to the CAN specification for more information.
Use CAN compatible cabling. J1939 cable is recommended as it is rated for on-engine use.
Shielded CAN cable is required. The module provides the CAN port shield connection ac
coupled to chassis ground. The chassis ground stud located on the mounting foot must be
tied directly to Earth Ground.
Network Construction
Axiomatic recommends that multi-drop networks be constructed using a “daisy chain” or
“backbone” configuration with short drop lines.
Termination
It is necessary to terminate the network with external termination resistors. The
resistors are 120 Ohm, 0.25W minimum, metal film or similar type. They should be placed
between CAN_H and CAN_L terminals at both ends of the network.
Mounting
Mounting ledges include holes sized for ¼ inch or M6 bolts. The bolt length will be
determined by the end-user’s mounting plate thickness. Typically ¾ inch (20 mm) is
adequate.
If the module is mounted without an enclosure, it should be mounted vertically with
connectors facing left and right to reduce likelihood of moisture entry.
The CAN wiring is considered intrinsically safe. The power wires are not considered
intrinsically safe and so in hazardous locations, they need to be located in conduit or conduit
trays at all times. The module must be mounted in an enclosure in hazardous locations for
this purpose.
No wire or cable harness should exceed 30 meters in length. The power input wiring should
be limited to 10 meters.
All field wiring should be suitable for the operating temperature range of the module.
Install the unit with appropriate space available for servicing and for adequate wire harness
access (6 inches or 15 cm) and strain relief (12 inches or 30 cm).
