UMAX090600 Version 1
Preliminary Documentation – May be Subject to Change
26-48
NOISE – ELECTRICAL CONNECTIONS AND SHIELDING
To reduce noise, separate all power and output wires from those of the input and CAN. Shielded
wires will protect against injected noise. Shield wires should be connected at the power or input
source, or at the output load.
The CAN shield can be connected at the controller using the CAN Shield pin provide on the
connector. However, the other end should not be connected in this case.
All wires used must be 16 or 18 AWG.
GROUNDING
Chassis ground should be connected to the module’s Frame GND pin to improve the EMI response
of the unit.
All chassis grounding should go to a single ground point designated for the machine and all related
equipment. Axiomatic recommends that the ground strap that provides a low impedance path for
EMI should be a ½ inch wide, flat, hollow braid, no more than 12 inches long .
CAN NETWORK CONSTRUCTION
Axiomatic recommends that multi-drop networks be constructed using a “daisy chain” or “backbone”
configuration with short drop lines.
CAN TERMINATION
It is necessary to terminate the network; therefore, an external CAN termination is required. No
more than two network terminators should be used on any one single network. A terminator is a
121
Ω
,
0.25 W, 1% metal film resistor placed between CAN_H and CAN_L terminals at the end two nodes
on a network.
