Micromod MOD: Remote I/O Modules for use with 2020N Remote I/O Interface Module - Manual (Page 12)

Remote I/O Modules
ELECTRICAL CONNECTIONS
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ELECTRICAL CONNECTIONS
3.1 CONNECTION GUIDELINES
Some installation rules have to be respected. These rules concern the ground concept, the
connection of the CS 31 bus and the different power supplies installations. The following
main principles must be applied:
• Each type of signal has to be mounted separately
- power supply 230 VAC
- low voltage signals
• The ground and power supply wires must be connected in star
• Refer to the description of each remote unit for connection of inputs and outputs.
• Installation of the bus
- The CS 31 bus is a RS 485 serial line and a shield twisted pair (the twisted pair
has to be symmetric).
- The CS 31 bus is a master slave bus. Only one master can be present on the bus.
- The maximum length between the both extremities is 500 meters.
- The master is a Remote I/O Interface Module
• Connections
- The same type of cable should be used throughout the installation for the system
bus (RS 485).
- Avoid interruption of the bus, for example, when connecting cables at the
marshaling cabinet.
- Whenever interruption of the bus is absolutely necessary, it must be wired to the
same side of the terminals.
Example:
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