Questions on deleting wrong data and what IP logger strores

[radioham]

My Vantage Pro2 station with IP logger and Cumulus is now running well. There are a few weeks of bad data due to teething problems that I want to clear.

Question 1: If I go through the log files and delete all the data before Jan 1, 2016 and then use the Edit to "Fetch log data", will it set up a new starting point for January 1 with all the correct maxima, minima etc.?

Question 2: How much is stored in the IP logger unit? When restarting Cumulus, it retrieves data. Is that from the IP logger? If I do question 1, will Cumulus just retrieve all the old stuff from the logger?

I could not find answers to these questions from the forum or other sources.

[steve]

Question 1: If I go through the log files and delete all the data before Jan 1, 2016 and then use the Edit to "Fetch log data", will it set up a new starting point for January 1 with all the correct maxima, minima etc.?

Yes.

Question 2: How much is stored in the IP logger unit?

The period covered depends on your logger interval (in the logger, not in Cumulus). It holds 2560 entries.

When restarting Cumulus, it retrieves data. Is that from the IP logger?

Yes, it uses that to catch up from the point it was closed down.

If I do question 1, will Cumulus just retrieve all the old stuff from the logger?

No, it uses the timestamp in today.ini when it starts up, to determine when it last wrote an entry to the log files, and only downloads archive data from that point.

[radioham]

Thank you so much.

[radioham]

A comment on recent experience with the IP logger.

Yesterday we had a power failure in our area from about 3 pm to 12:30 am this morning. The IP logger is supposed to save the data at the set intervals (10 minutes in my case), while Cumulus was shut down and Cumulus should retrieve it on restarting. Cumulus showed it was doing this, but there is a gap in the data. When I checked everything, I found the Console battery was low. The 3 C cells each had about 1.4 volts. I think what happened was the backup voltage from the Console battery was not enough to run the IP logger.

I had not checked the Console battery state regularly as I figured it would not be drained while on mains power, but this must not be the case. I guess the 3 C cells should be replaced from time to time. The new batteries show 4.81 volts in the Cumulus display.

I wondered if anyone else had this experience?

[AllyCat]

Hi,

The 3 C cells each had about 1.4 volts.

IMHO it's a "poor" design if it doesn't work properly with 1.4 volts per cell. Any reasonable design (even for Alkaline cells) should work down to 1.2 volts (still long before the manufacturers "end of life" value for Alkalines), allowing the use of (Low Self Discharge) NiMH cells if desired.

BUT, if it's using C cells then presumably the load current (when required) may be quite high, so you should really measure their terminal voltage on load. Also, even if there is no "continuous" drain, the "shelf life" of "carbon" (aka "Heavy Duty") type batteries is only a year or two, Alkalines probably 5 years and Lithium (non-rechargeables) perhaps 10 years (but expensive in C format).

Cheers, Alan.