How do NTP, PTP, TSN, and EtherCAT all compare?

Issue Details

I was curious about the difference between TSN, NTP, PTP, and EtherCAT. What are the advantages of each?

Solution

NTP: Network Time Protocol is synchronizing time to a server on the internet. It allows you to synchronize devices in different rooms, buildings, cities, etc. because they're all connecting to the same publicly accessible server. The downside is its accuracy (millisecond range). 

PTP: Precision Timing Protocol is the general term for IEEE-1588 which is only supported by some of our hardware because only some of our hardware supports hardware-based synchronization which is what you need to achieve the benefits (nanosecond precision) of PTP. Furthermore, the synchronization is limited to the local network. 

TSN: Time Sensitive Networking uses PTP (IEEE-802.1AS) to synchronize devices across a local network. TSN also has features that allow for deterministic communication over Ethernet, while still allowing other traffic over the network. 

EtherCAT: provides deterministic communication over Ethernet. It is a closed network though, so it cannot have non-EtherCAT devices on the network. It has other limitations but it is very common and relatively easy to use.