Manuals: orbplugin

This is a SeedLink plugin to grab data from an Antelope ORB. The plugin packages any selected data streams coming into the Antelope ring buffer as 512-byte big-endian miniSEED records and sends them to the controlling SeedLink daemon. No “re-ordering” of data is performed, it is assumed that data comes into the ORB sequentially. This may cause unexpected behavior with data streams allowing out-of-order transmission/reception such as CD-1, likely resulting in many unfilled miniSEED records.

All data streams are converted to miniSEED records except for any data that is already in a 512-byte miniSEED record. These records are passed directly to the SeedLink server, preserving the original data record (and included blockettes) that came into the ORB. The re-packaging of these ORB packets can be forced using the -p option.

The Seismological Communications Processor is developed by the GEOFON Project. The SeedLink server and protocol are used as the network transport layer of this system. For more information regarding SeisComP or SeedLink visit the GEOFON site at: http://www.gfz-potsdam.de/geofon/

Usage

orb_plugin [-v] [-t] [-m match] [-n number] [-s pktid|time] [-S statefile[:pkts]] -o orb 
Option Description
-v Verbosity, up to 3 levels.
-p Re-package original 512-byte miniSEED records
-t Trim partially overlapping data.
-m match Regular expression to match ORB packets, default is all waveform data.
-r reject Regular expression to reject ORB packets.
-n number Number of packets, otherwise continuous.
-s pktid|time Start position in ORB, pktid or time, default is next packet.
-S statefile[:pkts] File for saving/restoring the ORB position, restored ORB position is overridden by -s. The position will be saved every pkts number of packets received, if provided.
-o orb Required, location of the ORB in host:port format.

In the case of partially overlapping data, the data stream will be reset (and will include the overlap) unless the -t option is used.

Building

This software has been tested with Antelope 4.6, if you have an older version it will probably not compile.

This software requires an Antelope build environment for compilation. At a minimum the $ANTLOPE and $ANTELOPEMAKE environment variables should be set correctly.

A simple make should build the executable (orb_plugin) which can then be copied to the appropriate SeisComP installation.

Plugin.h

The SeedLink plugin interface code included with this software is from SeisComP-2.0 (SeedLink-3.0). If you are compiling for a different version of SeedLink you may need to replace plugin.h and plugin.c with those from the SeisComP/SeedLink system you are using.

Antelope runtime libraries

This software depends on the Antelope runtime libraries. This requires that the runtime libraries exist on the host executing the plugin, and thus, the host running the SeedLink daemon.

1001 blockette (timing quality)

The plugin will attempt to create a 1001 blockette in the same way as done by Comserv when the original data packet is of type QCDAT (Quanterra data as collected by qt2orb). Comserv will also modify the IO flags in the fixed header based on timing quality, this is not done here.

Original data stream mangling: since this plugin ‘repackages’ the data, i.e. record_in != record_out, the 1001 blockettes do not necessarily get packaged with the exact data they came in with, but they are probably never more than 1 record off (most likely only some fraction of a record). A very minor issue I think.

See Also

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