Hardware reference guide

Pwr. & Grnding. Guide
35013379 11/2011 749
Modbus Plus Grounding Figure
The following figure shows Modbus Plus grounding information.
Other Equipment Grounding
Other equipment in the installation should not share the grounding conductor of the
system. Each piece of equipment should have its own grounding conductor
returning to the main grounding point from which the equipment power originates.
Systems with Multiple Power Feeds
In systems with multiple power feeds, the grounding should proceed in the same
manner as single feed systems. However, a zero volt potential difference must be
maintained between the equipment grounding conductors of the separate systems
to prevent current flow on communication cables.
CAUTION
European compliance
To maintain CE compliance with the European Directive on EMC (89/336/EEC),
the Modbus Plus drop cables must be installed in accordance with these
instructions.
Failure to follow these instructions can result in injury or equipment damage.