2019-01-23 - 08:13
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 17 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 17 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