White Paper | Hybrid Servo Cables

MECHANICAL ROBUSTNESS While some hybrid cables will power stationary systems, most servo systems move. So look for hybrid cables that offer continuous flex performance and compatibility with cable tracks. These cables tend to use extra-fine Class 6 conductor wire, since it tolerates flexure better than the slightly coarser Class 5 wire used in static applications. For cable track compatibility, you’ll want cable constructions that minimize lay lengths and bend radii. A continuous flex hybrid cable will need more rigorous lifecycle testing. It’s essential to perform this testing under realistic conditions and with adequate bending cycles. At LAPP, for example, we subject continuous flex hybrid cables to as many as 10 million alternate bending cycles, capturing continuous dynamic data through each bend.

Power Conductors

Tinned Copper Braid

Signal Pair

Laminated Aluminum Foil

Control Pair

Power Conductors

Ground

SINGLE CABLE FUTURE It’s easy to see why hybrid cables for servo drives are a hot topic right now. This emerging approach to cabling can produce significant cost savings by eliminating the need for separate encoder cables, connectors and installation labor. With smaller drives in particular, the cost of a feedback cable and an M23 connector relative to the cost of the entire drive can be significant. Hybrid cables also take up less space in a cable carrier—by eliminating not just an encoder cable but also the minimum distance that must be maintained between conventional servo and encoder cables with different voltage classes.

Despite these benefits, keep in mind that there’s still work to be done before single-cable solutions take over our factory floors. In particular, not all motor and drive makers currently support the Hiperface DSL standard. And the ones that do are adding it to new servo products, so the single-cable approach targets new installations for now.

LAPP 29 Hanover Road, Florham Park, NJ 07932 T. 800 774 3539

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