The sercos protocol – the DNA for your industrial communication

sercos uses a powerful protocol to meet the needs of today’s industrial automation solutions. It combines the advantages of the non-proprietary Ethernet standard with the real-time precision of industrial automation technology.

sercos uses IEEE 802.3 compliant Ethertype 0x88CD to send data in cyclic messages (telegrams), which provide M/S, SVC, CC, SMP and Safety communication channels and fully meet industrial real-time requirements. The data consists of standardized motion, drive and I/O profile parameters.

The telegram types are listed below:
 

Master Data Telegram (MDT):

The master sends command data to the slaves.
 

Acknowledge Telegram (AT):

The slaves send status data back to the master and to other slave devices.
 

The attached devices are identified, addressed and configured during the initialization phase. Device channels are allocated to each slave in the MDT and AT. The slaves read data from and write data to the channels.
Up to 4 MDTs and 4 ATs are sent from the master per clock cycle depending on the data volume. Telegrams transport data from device to device. The relevant command data is read or the requested status data is written in each of the devices.
Processing is done in hardware (“on-the-fly”) while the telegrams are passing through a node.
 

Open sercos III communication cycle