TSN- Right Protocol for The Right Task

Ethernet is the most used communication medium for most of the protocols being used in Industrial automation industry. Ethernet standards had undergone a lot of evolution since its invention in 1970s with 10 mbps speed to Gigabit level of speeds in the modern era. Ethernet communications are acceptable across industry because of its speed, flexibility, scalability, openness, and reliability. However, the real challenge in ethernet communication is the lack of determinism. That means you can send any amount of data in a relatively higher speed, but you cannot be sure about the time at which those data will get delivered.?Since ethernet standard is based on the best effort delivery principle, a lot of factors like the number of devices, amount of data etc. will affect the delivery of data.?

In an IOT agnostic world with increasing demand of data volume which hasto be transferred along with the time critical data, a deterministic ethernet communication has become an inevitable factor. Thus, many proprietary deterministic ethernet protocols like ethercat , sercos, profinet IRT etc. got introduced into the industry at the cost of openness of ethernet communication.

Time Sensitive Networking (TSN) is a set of IEEE 802 standards to make ethernet communication deterministic. It can guarantee the data delivery within a precise time. Following are the points behind the acceptability of TSN

TSN is Universal: The good news is that even if TSN is a new technology, it still follows the tradition of ethernet by being backward compatible and hence its easy to introduce TSN to existing old networks as well. That means the devices which don’t support TSN also can be connected to a TSN network compromising the complete benefits of TSM optimized networks

Time is the key: Time synchronization and time scheduling are too crucial for a TSN network. All devices and switches in a TSN network should be synchronized with a common clock to ensure that everything arrives on time.?

Reserved Paths : The streams will always describe the path between the origin and destination to ensure increased priority for critical data

Frame Preemption: Larger frames will be split at the starting point and reassembled at the destination for the effective use of bandwidth, and this reduces residence time inside switches and ultimately the time will get saved

Improved Availability: Redundant streams can be employed into the network for creating redundant network paths and this will ensure the seamless transportation of time critical data at the event of the failure of a device or a node.

Conclusion:

Current industrial trends lead to an increased traffic in any industrial automation network consisting of sensors, remote IOs, HMIs, PLCs, SCADA systems, NVRs, along with big data server systems. TSN with its convergence, scalability, flexibility, ease of use and determinism can handle all the data with required priority keeping the cycle times down to 31.25 μsec with 1 μsec for jitter.

Yes, TSN is a great step towards open eco system