While each individual sensor was initially connected via a wire pair of a control/electronics cable, since the end of the 1980s sensors have been connected via serial bus systems such as Profibus. Only two wires are required to address all sensors; the sensor is selected via the protocol. Due to ever-increasing data rates, Ethernet networks have been gaining in importance since 2014. According to a market study by HMS, industrial Ethernet systems have now overtaken traditional fieldbuses in terms of newly installed nodes in factory automation: the share of industrial Ethernet in newly installed nodes grew by six percentage points in 2018 compared to the previous year, reaching a market share of 52%.

Use in the drag chain

SPE simplifies integration into existing networks with its uniform cabling structure and standardized transmission protocols (TCP/IP). The use of PoDL enables the simultaneous transmission of data and power via a single cable, which - thanks to reduced weight and space savings - is particularly advantageous for drag chain applications.

However, it is often unsuitable cables in drag chain applications that lead to premature failures and unplanned downtimes of entire production lines. Bending radius, travel distance, speed and acceleration are the critical points that influence the service life of the installed cable. This means that factors such as design, material selection and production process are decisive for a reliable drag chain cable. In particular, the choice of a mechanically and electrically suitable insulation material in conjunction with optimized stranding parameters plays an important role. The type and design parameters of the shielding also influence the service life of the cable. Finally, when selecting the sheath material, chemical resistance to various substances must often be taken into account in addition to mechanical robustness combined with the greatest possible flexibility.

The halogen-free, silicone-free and RoHS-compliant 'Superflex' single-pair Ethernet cable from Lütze therefore offers high active and passive interference immunity (EMC) and can be used in a temperature range of -30 to +70 °C in mobile applications. It has a minimum bending radius of 70.5 mm and is therefore ideal for permanent and fail-safe use in the drag chain. The cable is particularly suitable for permanently moving applications in mechanical and plant engineering as well as in automation, transportation and conveyor technology for industries such as automotive engineering, machine tool construction, but also in wood processing and airport technology.

Authors:
Cécile Lascaux is Product Market Manager Cable at Friedrich Lütze in Weinstadt;
Johannes-Josef Lentzen is Product Manager Cable at Friedrich Lütze in Weinstadt.