Using time webtags and subtracting minutes

[espana23]

Hi,

I am using the "iCumulus for iPhone" web tool and trying to add a section to it which will display wind readings every 5 minutes for the past 3 hours. For example the section could look something like this:

10:55pm - 18kts
10:50pm - 16kts
10:45pm - 17kts
etc.

As far as the wind readings go I plan to use the webtag <#RecentWindSpeed m=5>, <#RecentWindSpeed m=10>, <#RecentWindSpeed m=15>, etc.. This is the right way to do it, correct?
For the timestamp part I was thinking of using the webtags <#hour>:<#minute> but I cannot find a way to go back 5 minutes at a time for the older timestamps. Is there a way for me to do this using the aforementioned webtags or do I need to use a different method to do this?

Thank you.

[steve]

The <#RecentTS> web tag will give you the timestamp of the corresponding data, when used with the same parameters.

http://wiki.sandaysoft.com/a/Webtags#Recent_History

[espana23]

Thanks a lot Steve.

[espana23]

Hi Steve,

I am using the <#RecentTS> tag to get recent historical data of 5 minutes back at a time for up to 3 hours back. I noticed that the time stamps of <#RecentTS> depend on the time that the page gets updated which makes sense. For example if the webpage gets updated at 19:13, then the first time stamp will be at 19:13 (m=0), the previous at 19:09 (m=5), the previous at 19:04 (m=10), the previous at 18:59 (m=15) etc. In my case I would prefer it if the historical data I am providing are at uniform timestamps such as 19:10, 19:05, 19:00, 18:55 etc (i.e on the 5th and 10th minutes). Is there any way for me to get that?

Thank you.

[steve]

How often are you uploading your web pages? If you do them at 5 minute intervals, then do the 'recent' timestamps not correspond to 5 minute intervals on the clock?

[espana23]

I am uploading the web pages every 5 minutes. I can see on the "last update" tag that the time for example is at 19:30:01 and the next update is at 19:35:01, so the web page itself appears to update on the 5 minute intervals on the clock. For some reason though the 'recent' timestamps are a bit off. Maybe instead of m=5, m=10, m=15, etc. I should be using m=4, m=9, m=14, etc?

[espana23]

I was able to get the timestamps to be on the 5th and 10th minutes by using m=0, m=6, m=11, m=16, m=21, etc.

On a related note I have another question about the Recent History webtags and the Logger Interval set at Cumulus. On the wiki, at the section of Recent History webtags it mentions that "When Cumulus is re-started the array it sets up will be based on reading the logs, so the contents will initially have a resolution according to the logger interval you have set in Cumulus and/or your station. You'll get the nearest value if you ask for a time for which there is currently no exact match, and the first tag listed tells you that nearest time." In my case, I am using WS3083 and according to the manufacturer's manual the "Logger Interval" should be set to 30 minutes. In my case, I turn Cumulus OFF at night and then ON again in the morning. Since I am using the Recent History wetags and want to provide historical data in 5 minute intervals, I changed the Logging Interval in Cumulus at 5 mins, but the results that I get the next morning I turn Cumulus ON are not correct. It basically does not include any historical data while Cumulus off. My question is the following. The fact that the manufacturer says to use 30 minutes for the Logging Interval, does it means that that's the only correct setting for their station to work properly with Cumulus in regards to logging data while Cumulus is OFF? Is there any way for me to get the logging interval to be every 5 minutes while Cumulus is off?

Thanks.

[steve]

Your station can use logger intervals other than 30 minutes, and in fact 30 minutes is not a very useful interval. If you look on the downloads page, I have provided a utility to set the logger interval on Fine Offset stations. You can thus set it to 5 minutes. Note that the timestamps from logger data may not correspond with timestamps from live data, as the station does not timestamp the logger entries, and Cumulus has to calculate a timestamp for each one by working backwards from the current time. The result may not be aligned to 5 past the hour (etc) on the clock, as the station does not align its entries to the clock as Cumulus does.

Even with a 30 minute interval, Cumulus should still be downloading those 30-minute entries when you start it up. If you zip up the diags folder and attach it to a reply in this thread, I'll take a look.

[espana23]

When I use a 30 minutes logger interval it appears to log correctly the wind readings every 30 minutes. Changing it to 5 minutes though does not show any readings for the Recent History data.

I will use the utility you mention below to change the logger interval for my Fine Offset station. Why is this utility needed for Fine Offset stations? Does this mean that the Logger Interval setting under the Station window works for some values and not for others when the station is of Fine Offset type?

Thanks.

[steve]

The Cumulus logging interval and the station logging interval are independent. Changing one has no effect on the other.

[espana23]

I see. Now I understand. I will try the utility and see how it goes.

Thanks for the help.

[espana23]

In the readme.txt file of the utility it says not to run the utility while other software are using the station. Does this mean that Cumulus shouldn't be running as well?

[steve]

Yes, Cumulus is 'other software'. Two programs can't communicate (successfully) with the station at the same time.

[espana23]

Ok, thanks.