Markus Zolliker
8663501150
- created secop_v2017-09-14.rst, based on the GoogleDocs SECoP Preliminary V2016-11-30 (rc 2) - this Document is supposed to contain the full SECoP standard - created SECoP issues - moved everything else to "outdated" (kept for reference) Change-Id: I87d69d1846fc4ed55f1c78b22fd4650d8550152b Reviewed-on: https://forge.frm2.tum.de/review/16573 Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de> Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
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SECoP Issue 7: Time Synchronization (under discussion)
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As a SECoP server and a SECoP client might not run with a common clock,
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the SECoP client should be able to correct for time slips.
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The recommended mechanism is (proposal by Markus):
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After connecting to a server, the client records its internal time before sending
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a ping request.
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If the pong request does not contain a timestamp,
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the client knows, that the SEC node does not provide timestamps and
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therefore it has to create timestamps on the time of reception of messages.
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If the returned timestamp lies between the time the ping message was sent and the
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time the pong message was received, it does not need to correct the timestamps.
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If not, the average of the 'ping' time and the 'pong' time is calculated and
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the difference to the received timestamp is used for correcting further
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timestamps.
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On the meetings in Berlin and Garching in 2017 it was proposed to put this into
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the standard, the exact wording has to be decided.
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