El dimarts, 15 març de 2016 3:06:52 UTC+1, mwall va escriure: > > hi george, > > as of 3.5.0, when you install weewx and choose fousb driver, > record_generation will be set to software. this will also happen if you do > a 'wee_config --reconfigure' and choose fousb. > > there are two reasons for this change: > > 1) the factory default archive interval for fine offset stations is 30 > minutes. so when record_generation=hardware, noobs are confused when their > station reports data only every 30 minutes. > > 2) when record_generation=hardware, the fousb driver must sync with the > station to read just the latest record. each sync is a chance for usb > lockup. when the archive interval is large-ish (e.g., 30 minutes) this is > less of a problem than when it is small-ish (e.g., 5 minutes). >
Thanks Matthew, Can you please elaborate on point 2? I read the documentation several times but it still confuses me. If doing record_generation by software, does not weewx need to read the LOOP packets (either adaptively every 48s or according the configured period), thus increasing the chance for USB lockup? I thought that record_generation = hardware, would require only one read of a RECORD packet per archive_interval, and hence it would generate less USB traffic, but I am obviously wrong. What does that sync() operation do, which is more expensive than reading the LOOP packets in terms of USB usage? And a related question regarding different values archive interval in a FO station and in weewx.conf. >From the documentation, I guess that when using hardware record generation, if the values differ, the one from the station is used. But what happens when using software record generation? Does weewx honor the value from the station or from the configuration file? A possible scenario: Using software record generation, use a short archive interval in weewx.conf to get updated reports quite often. At the same time, have a longer archive interval in the station, so that in case of power failure, the console can keep on storing records for a longer period of time (at expenses of time resoultion of course). A last question arises from this: at startup, does weewx catch up all the missing records stored in the station even when record generation is set to software? -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
