I know you are working on another bug report of mine regarding Synthetic Channel dropouts (thank you!), but I thought I'd pass along this one as it, potentially, affects more users.
Apparently, CWOP expects altimeter values for their "barometer" spec. Unfortunately, there is not a way to get this value out of Davis VP2 consoles as they only transmit mean sea level pressure (MSLP). For reference see:
http://server.gladstonefamily.net/pipermail/wxqc/2006-July/004319.html. I found that link in CWOP's FAQs.
Because WeatherCat simply passes on MSLP to CWOP, sometimes I get data quality errors from MADIS, particularly during the cold months, because my pressure is too high.
Other software packages, like WeatherLink, are taking that MSLP value from the VP2 and working backward to get altimeter.
Note: this does not affect Vantage Vue users since the Vue console CAN be set to pass altimeter.
UPDATE 28 Jun: I found the Davis formula for MSLP (see pg 28-9):
http://www.davisnet.com/product_documents/weather/app_notes/AN_28-derived-weather-variables.pdf UPDATE 29 Jun: Found some open-source python code that converts various weather stations' pressure implementations to altimeter including the VP2! The rub here is that to automate the conversion we would need a new tag 12HOURSAGO (similar to 24HOURSAGO) which currently doesn't exist in WeatherCat. I am in the process of mocking up a simplified PHP version of this script for the VP2 only (for use with the SQL driver to pull historical temps from db). For now, here's the original [attached].
I very much appreciate your efforts at continual improvement of WeatherCat!