Service & IP Channels

Sercos I and II include a service channel, which can be used for the transfer of communication data, parameters and diagnostic data. To maintain downward compatibility, Sercos-III also has the service channel.

An additional optional IP channel can be added for transfer of non-realtime data via standard Ethernet frames. This carries general Ethernet messages and IP-based protocols such as TCP/IP and UDP/IP. The advantage of the IP channel is that telegrams from superior networks (office network, wide area network) can be directly transmitted "up/down to" the drive or I/O. Because this transmission occurs in a separate channel, it does not affect the real-time data exchange between the devices. This improves the ease of integration by supporting higher protocols from office and fieldbus communication (e.g., TCP/IP, Profinet and CIP).

The cyclic channel and IP channel are configurable. Cycle times and separation of real-time and non-real-time channels can be adapted to the particular application. Thus, Sercos III combines even the most mission-critical real-time qualities with Ethernet technology.

Sercos communications uses Master Synchronization Telegrams (MST), MasterData Telegrams (MDT), and Amplifier Telegrams (AT) to send real-time information to/from controllers and drives. These real-time telegrams plus non-real-time IP channel telegrams are embedded in Standard Ethernet frames.

Cyclic and Non-cyclic Communication