`Next generation` Sercos will move closer to Ethernet

Work has started on a new version of the Sercos motion control interface that will contain several extensions and enhancements, including a closer alignment with industrial Ethernet. The "next generation Sercos" project is being led by the Interest Group Sercos (IGS), which aims to present its plans at the SPS/IPC/Drives show in Nuremberg, Germany, in November.

The proposed enhancements for this third generation of Sercos include:

• improving the ease of integration by supporting higher-level fieldbus and office communications, such as TCP/IP, Profibus and CIP;

• introducing higher transmission speeds;

• improving the inter-operability of control and drive components by defining motion control profiles and developing test suites to check conformance; and

• cutting the costs of the technology.

Sercos was originally developed as a digital drive interface during the late 1980s by a largely German industrial consortium. The first generation supported transmission speeds up to 4Mb/s and was used mainly in high-performance machine tools. In 1995, Sercos became an international standard, IEC 61491.

A second generation, capable of transmitting at speeds of up to 16Mb/s became available in 2001. Sercos can now control and synchronise up to 40 axes in real-time, with 1ms cycle times and a jitter of less than 1µs. But it is facing an increasing challenge from other technologies based on standards such as Firewire and Industrial Ethernet.

Several IGS working groups are developing proposals for the third generation of the interface. Detailed application and development work is expected to start following the Nuremberg presentation.