This is the current version used for producing METARs, etc. Usually the NWS is about 20 years behind on publishing new material.Another good reference - National Weather Service Handbook #8 however it's from 1996.
I believe the output from an AWOS/ASOS is something like every 3 minutes (depends on the system and how new it is). While it outputs often, the ATIS is only updated with the current wx information every hour (or when a SPECI warrants) and at large airports the data is looked at by a weather observer to check for accuracies and change anything that is incorrect. Most of your normal METARs are normally the exact data from the AWOS/ASOS but they aren't perfect, which is why the weather observer checks the data for accuracies.but more often an AWOS or ASOS.