Osmosis/keep a local copy of a .osm file updated using minutely updates
First get tendring.osm by downloading a Geofabrik extract in non-pbf format, and extracting it using
osmosis --rx essex.osm.gz2 --bp clipIncompleteEntities=yes file=tendring.txt --wx tendring.osm
The tendring.txt bounding polygon is available from the Tendring(Essex District) page.
Once only execute
to prepare for synchronisation.
Edit configuration.txt if you want to download more than 3600 seconds worth of updates at a time, or want to use hourly diffs rather than minutely.
Download a state.txt file from planet.openstreetmap.org - pick a nnn.state.txt earlier than the Geofabrik extract timestamp (I chose 23:59 of previous day) and save in same folder as configuration.txt as state.txt
osmosis --rri --simc --rx tendring.osm --ac --bp clipIncompleteEntities=yes file=tendring.txt --wx new.osm && copy new.osm tendring.osm /y && del new.osm
as often as it takes to catch up. The above is for Windows 7. Linux seems to have a mv command which will replace the copy and del commands. See the planet.osm/FAQ which is what I based the above on.