Sequence of events in logging

[aaardvaark]

Newbie here. I've installed my WH1091 and got it working with Cumulus, more or less. And I've gone through the FAQ and Wiki (I think, not sure how much of the Wiki I've covered) and read anything that looked relevant on these forums. The following is general question relating to how Cumulus works with these stations but my specific example is my Finesoft WH1091. I'm assuming station setting is set to type = "Fine Offset" (and not "Easyweather"), and "Use data logger" is on. I haven't got to web publishing so this only applies to getting the info onto my own screen.

My questions are simple; that I've either missed or are not covered because they're so basic.

Can someone please point me to where I can find a summary of the sequence of events and timing involved in getting a reading from my sensors to a cumulus display?

To rephrase and expand with my possibly erroneous understanding:

- every 10 seconds or so, Cumulus seems to read data from the console and update the screen display. (I think Easyweather did it about every 15 seconds). How often does the console update? Does Cumulus update in sync with the console or does Cumulus read data from the console at it's own rate? What sets these update rates?

- is this data rate essentially what is referred to as "real time" for Cumulus?

- then Cumulus makes a log record in the monthly file every x minutes (x = 5 mins to 250 mins, this period being set by the Easyweather software and is not setable any other way(?). Is this right?) If this is right then I'm confused why the interval is not simply set in Cumulus which polls for the info when it wants.

- where does Cumulus get its info from? From the current 'real time' figures in the console's brain, or from the last record logged by the console, or a combination? Does this depend on the setting of "Use data logger" in station settings? I guess that in normal operation (i.e. when CUmulus is not trying to catch up after being re-started) it reads data from the console's real time brain and the console's data log is ignored. Is this correct?

- I read somewhere (that I can't find now unfortunately) Steve suggesting that it makes more sense to disable the data logging and use real time by leaving the software on all the time. What does this mean? Or have I got that completely wrong?

Thanks in advance,
Julian

[steve]

every 10 seconds or so, Cumulus seems to read data from the console and update the screen display. (I think Easyweather did it about every 15 seconds). How often does the console update? Does Cumulus update in sync with the console or does Cumulus read data from the console at it's own rate? What sets these update rates?

The station updates every 48 seconds. Cumulus has no idea when it's going to update, so it reads every 10 seconds, so as to get new data reasonably soon after it has updated. It treats each 10-second reading as a new set of data, even if it hasn't changed.

- is this data rate essentially what is referred to as "real time" for Cumulus?

I'm not sure what you mean. To me, 'real time' usually refers to updating a web site at a relatively high rate (every few seconds). But I suppose you might refer to data collection while Cumulus is actually running as 'real time', as opposed to using data from the station logger.

- then Cumulus makes a log record in the monthly file every x minutes (x = 5 mins to 250 mins, this period being set by the Easyweather software and is not setable any other way(?). Is this right?) If this is right then I'm confused why the interval is not simply set in Cumulus which polls for the info when it wants.

The logging period in Cumulus can be set from 1 minute to 30 minutes, and is completely independent of the station. Except that, when reading 'historical' data from the station at start up, Cumulus logs each 'history record' from the station as an entry in its own log, so in that case it is using the logger interval set in the station.

- where does Cumulus get its info from? From the current 'real time' figures in the console's brain, or from the last record logged by the console, or a combination?

When running 'live', it's the 48-second console updates - the 'live' data, if you like.

Does this depend on the setting of "Use data logger" in station settings?

That setting only determines what Cumulus does at start up and is really only for diagnostic purposes. Normally you leave it set as otherwise you might get gaps in your data if you had Cumulus not running for a period of time.

I guess that in normal operation (i.e. when CUmulus is not trying to catch up after being re-started) it reads data from the console's real time brain and the console's data log is ignored. Is this correct?

Essentially, yes. At the risk of confusing things, I should perhaps point out that with Fine Offset stations, it's actually read from the same place. The location of the current data is actually an entry in the logger. The station keeps overwriting the current memory location until the configured logger interval (the station one, not the Cumulus one) is reached, then it steps on and starts writing to a new location.

- I read somewhere (that I can't find now unfortunately) Steve suggesting that it makes more sense to disable the data logging and use real time by leaving the software on all the time. What does this mean? Or have I got that completely wrong?

It's not really a case of disabling anything. I'm just making the point that you potentially get better results by leaving your PC and Cumulus on 24 hours a day, than you do if you switch off overnight, or for any other period.

[aaardvaark]

Thanks Steve, long answer much appreciated and perfectly answers my questions.