2 seedlink – Guralp Systems CMG-DCM User Manual
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CMG-DCM Data Communications Module
your instrumentation whilst minimizing the bandwidth used.
datatransfer.scream.server.coalesce : Some digitizers are configured to
produce GCF blocks at higher than normal rates. This may be done, for
example, to reduce the latency in data transmission. Blocks produced
this way may not all be full, so space will be wasted in the recording
medium.
Selecting this option makes the DCM build full GCF blocks from the
data it receives (a process known as
re-blocking) before transmitting
them.
If you enable
datatransfer.scream.server.coalesce, you will not be able
to connect to the terminal of any connected digitizers using the
Scream! server (
i.e.
the DCM will behave as if
datatransfer.scream.server.allowserialaccess was no.)
You can still configure the digitizers using the Web page (Section 7,
page 105) or using command line tools like minicom and gcli (see
5.2 SeedLink
SeedLink is another member of the SEED / MiniSEED family of
formats, designed for transferring seismic data over a network. The
DCM's slserver package provides a SeedLink server.
SeedLink expects streams to be named using station, channel, and
network codes according to the FSDN SEED naming convention.
Before using the SeedLink server, you will need to define these codes
for every stream you expect to receive. This is done on the Seed name
mappings page (see Section 5.7, page 75.)
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