Tips when cabling an industrial communications system
The cabling of an industrial communications system is reliable and cost-effective when correctly implemented. Avoid typical problems by observing the following rules:
- Utilise components suitable for the communication system.
- Use environmentally-friendly components
- Additional loads ie continuous motion and torsion, must be specified by manufacturers in the data sheet.
- Missing or incorrect terminating resistors often result in sporadic failures.
- Avoid incorrect assignment: Incorrect pin numbering and conductor colours result in total failure.
- Components that do not match one another, or a circuit that has been incorrectly connected up, result in unreliable contact points.
- Carefully connect the shield: A 360°contact of the braided shield prevents sporadic failures for increased levels of EMC (electromagnetic compatibility) stress.
- Suitable potential bonding must be implemented: Only a meshed system and a power supply in accordance with TN-S (earthing system) can avoid equalisation currents and therefore interference via the shield. Fibre-optic cables must be used if these conditions are not met.
- Cabling drawings must be updated after any change so that faults can be located after a failure.
- The transmission medium, whether electrical or optical, is a critical part of any industrial communications system.
- All components used in the transmission network must be chosen based on the environmental conditions to which they will be exposed.
- The right component for all applications exists – it must just be specified and used.
Classic fieldbus up to high-speed Ethernet: Communication plug connectors for industrial use
By Dipl-Wirt-Ing. B Horrmeyer, Phoenix Contact (Germany)
Electricity+Control: January 2012 (pgs 4 – 6).