2018-11-14 - 16:20
OSADL Projects

OSADL Realtime QA Farm

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Real-time Ethernet (TSN) synchronization analysis (peer-to-peer)

Peer-to-peer topology with a PTP grandmaster and a PTP slave directly connected to each other
Peer-to-peer topology with a PTP grandmaster and a PTP slave directly connected to each other

Peer-to-peerStar topology

One of the Linux real-time test systems (rack #c, slot #8 at primary position) serves as PTP grandmaster while receiving global time information via NTP in the same way as all other systems. This PTP server is connected via a peer-to-peer link to another real-time test system (rack #0, slot #8 at shadow position) that is configured as PTP slave. As can be derived from the below depicted jitter plots over time, SO_TXTIME flagged packets such as implemented in an OPC UA PubSub scenario can be sent across the peers with a predictable arrival time at the destination peer. The two computer systems, the PTP grandmaster and the PTP slave, are equipped with an Intel I210-T1 network adapter integrating an Intel I210 network controller.

PTP grandmaster: Jitter analysis from system time to network adapter by week

Last update 4 minutes ago

Jitter analysis of time synchronization to the network adapter
Please note that the recorded values of this and of all below plots represent the maximum of subsequent 5-min intervals. Thus, from the given numerical values below the plot the only meaningful value is the one in the column labeled "Max:".

 

PTP client #1: Jitter analysis from network to network adapter and from network adapter to system by week

Last update 4 minutes ago

Jitter analysis of the network adapter
Jitter analysis from network to network adapter

Jitter analysis of the system
Jitter analysis from network adapter to system time