John,
What you are seeing is one of two things. First it could be the command
station. When it does a power on to the track, it sends special commands
(what you see) to ask all devices on the layout to report their status. The
other is when JMRI starts up, it too issues the sequence to ask all devices
to report their status. This is how JMRI learns the current status of
turnouts and sensors and updates the tables. Otherwise, until a turnout
moved, or a sensor changed, you would see 'Unknown' as the status.
-Ken Cameron, Member JMRI Dev Team
www.jmri.org
www.fingerlakeslivesteamers.org
www.cnymod.com
www.syracusemodelrr.org
Ken Cameron