Controller and Communication Modules
A large range of hardware options is available including FPGA components, ASICs and microprocessors with integrated Sercos functionality.
On the slave side, specific hardware is always used which handles the fast telegram processing, the synchronization, the topology switching, the direct linking up of any Ethernet node, the hot plugging and the direct cross-communication.
On the master side, either specific hardware (“hard master”) or, alternatively, a standard Ethernet controller (“soft master”) is used.
Different versions of FPGA components for Sercos III are offered by Altera, Lattice and Xilinx. The FPGA components are either used purely as Sercos III communications controllers or as universal SOPC solutions (system on a programmable chip) with integrated Sercos III logic.
The IP core for the FPGA components can be licensed from Sercos International as a netlist or bit stream.
Single payment or run-time license models are available. Companies which are a member of Sercos International, Sercos North America or Sercos Asia receive a discount. Upon request, manufacturers who are interested will receive a price list and the license agreement which must be signed. A license for the IP source code, e.g., for the development of an ASIC, is also available. In this case, a suitable license is agreed upon based on the focus of the project. Maintenance and technical support is provided by the company Automata.
Particularly time-saving and inexpensive implementation is possible with the EasySlave. The FPGA-based EasySlave can be used for simple peripheral I/O devices, e.g. encoders, measuring probes or valve terminals. To be able to achieve this, single chip implementation is used which eliminates the additional CPU and can be integrated into slave devices with minimal development and integration costs. Maintenance and technical support for the EasySlave is provided by the Steinbeis Transfer Center in Esslingen, Germany.
In addition to FPGA-based controllers, several manufacturers offer ASIC and processor solutions with different ranges of function and performance. Some are simply communication controllers that only contain hardware-related Sercos functions. In addition to the hardware-related Sercos functions, other controllers also incorporate other interfaces and user logic.
Device manufacturers can integrate the Sercos controllers into their own hardware or, alternatively, can use ready-made designs or communication modules. The first option requires more development expense but optimizes manufacturing costs. The second option shortens the development phase considerably, but leads to higher manufacturing costs.
Standard PCs can be equipped with ready-made expansion cards. Both active boards with their own CPU and passive boards without CPU are available. The cards are connected via PC buses, e.g. PCI. If a soft master is implemented, the “on board” Ethernet controller can be used.
Various manufacturers offer evaluation and/or starter kits which include sample codes and make it easy to start developing Sercos interfaces.