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Re: Three questions for al earthwormers



Steve,

     I think that we can help you with your first problem:

> 1. A way to get state-of-health from refteks using PPP with a 422 card and
> rtpd. In particular we need to know if the GPS clock is locking when it
> should.  Right now we have no way of knowing this info without visiting the
> site.

     There is a University of Utah contributed Earthworm module called
ref2disk, written by Dave Chavez and Ali Moeinvaziri, which captures
and stores the state-of-health information from the REF TEKs (including
state-of-health messages about the clock).  In our current earthworm
setup, reftektoew takes all telemetry packets received from the reftek
data loggers via rtpd and sends them to a raw ring.  These packets are
of various types including waveform data packets, state-of-health packets,
and station/channel packets.  Additionally, reftektoew converts the
waveform packets to tracebuf packets and sends them to a wave ring.

     The ref2disk module reads the telemetry packets from the raw ring,
writes the waveform data to disk files in SAC format, and writes all
non-wavefrom packets (station/channel and state-of-health) to disk as
binary files.  These files can be read using the Passcal program
refpacket.  Our technicians regularly look at these files to detect and
diagnose problems with the REF TEKs.  Ref2disk uses the station/channel
information to set some of the SAC header variables.

     The state-of-health packets are periodically sent back to the
recording center by the REF TEKs, at least in our setup.  We don't have
to request them.  The station/channel packets are sent back whenever
data acquisition is started.  We are not using 422 cards in our
REF TEKs right now, because we are still using an older REF TEK
digital telemetry system.  However, as far as I know the same types of
data packets should be sent back from the REF TEKs regardless of the
telemetry protocols used.

     The current documentation for ref2disk on the earthworm web site
does not mention the treatment of the state-of-health packets.  We will 
get that added.  In the meantime, if you have any questions about this
module, you may contact Ali Moeinvaziri at ali@seis.utah.edu.

--Jim Pechmann

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