Hello, I hope this message finds you well.
We are currently analyzing a configuration where the same PMUs are being forwarded from openPDC_1 to other PDCs through two different streams:
- Stream_2: using the Output Stream of openPDC_1 in C37.118 protocol*
- Stream_3: using the STTP protocol*
Both streams carry identical sets of PMUs.
When using Stream_2, we are able to view detailed statistics information in openPDC_3 — including stream latency, data frames received, expected, and lost — as expected from the standard openPDC_1 outputs.
However, when using Stream_3 (STTP), these same statistical metrics do not appear in openPDC_3.
Is it possible for openPDC_3 to also calculate and display these statistical metrics (e.g., latency, frames received/lost, etc.) when data is transmitted via STTP, just like openPDC_2 does?
Any clarification would be greatly appreciated.
Best regards,
Renan Pires
Hello Renan Pires,
It is not actually possible to compute the exact same set of statistics. In particular, STTP is not a frame-based protocol so any statistics related to frame counts or frame rates simply wouldn’t apply.
For latency, I do see that the “lifetime latency” statistics are provided by the STTP subscriber. Honestly, I’m not sure why Lifetime Maximum Latency is missing from your screenshot–it is supposed to be UDP1_1!SUB-ST13. Maybe check if a measurement with that signal reference exists and whether it is associated with the STTP subscriber device record. If you can figure out why that statistic is missing and how to get it back, I expect you should be able to see that statistic as well.
As for any of the other input stream statistics that are currently unavailable from the STTP subscriber, assuming it is theoretically possible to compute them, then it should also be possible to update the source code to provide them. Unfortunately, it is not something you can make happen through configuration alone.
Thanks,
Stephen
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