Guralp Systems CMG-DM24 User Manual

Page 26

CMG-DM24

HOURFILES command, which takes four parameters (which precede

the command – see chapter 5, page 51 for details of the DM24's
internal FORTH interpreter):

FAST SPS SLOW STATUS HOURFILES

FAST specifies the file size, in hours, for sample rates

≥

SPS

SLOW is the size, in hours, for lower sample rates < SPS

STATUS is the size, in hours, for status stream files.

The default settings are:

1 40 4 12 HOURFILES

With these settings, the system will start a new file every hour for
streams with a sample rate

≥

40 samples per second.

Lower sample rate streams will have files which last 4 hours – so the
file names will have the sequence “YYMMDD00, YYMMDD04,

YYMMDD08” etc.

Status files will have 12 hour granularity i.e. “YYMMDD00 and
YYMMDD12”.

Note that status streams are recorded as plain text files with the

extension '.txt'.

All other streams are recorded with the extension '.gcf' which is the
same format used by 'Scream!' (i.e. a series of 1k 'gcf' data blocks),

consequently the files can be viewed and processed by Scream!,
simply by “drag and dropping” or right-clicking to select the option.

Due to bandwidth and processing limitations, it may not always be

possible to record continuous streams with particularly high sample
rates. Note that when triggers are in use, the sample rates of streams

transmitted over the serial port will typically increase considerably. If
your application involves sample rates higher than 250 samples per

second, you should verify to your own satisfaction correct operation
(under triggered conditions, if necessary) with your own USB devices

before permanent installation.

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