Guralp Systems CMG-DM24 - Manual (Page 82)

CMG-DM24
stored for later transmission. MS-GAP sets the interval the digitizer
should wait for an acknowledgement message, before assuming that
the block could not be transmitted. If a period of interval passes
without an acknowledgement, the digitizer's behaviour then depends
on the current transmission mode (see above).
interval is measured in milliseconds. The default is 150. If the value
is greater than the average time between blocks being generated, and
an outage occurs in the return communications link, the digitizer will
be producing data faster than it can transmit it, and gaps will start to
be observed. However, systems using slower communications links
(e.g. radio links) may be unable to acknowledge blocks in under 150
ms. You should choose a value for interval which is suitable for
your particular installation.
RE-USE
Syntax: RE-USE
Instructs the DM24 to use its Flash memory as a circular buffer,
overwriting the oldest data when it becomes full.
In this mode, the Flash memory will always contain the latest data.
WRITE-ONCE
Syntax: WRITE-ONCE
Instructs the DM24 not to overwrite data in the Flash memory when it
becomes full Instead, when the digitizer runs out of space, it switches
to DIRECT transmission mode and will leave the Flash memory
untouched.
In this mode, the Flash memory will always contain the earliest data.
MODE?
Syntax: MODE?
Queries and displays the current Flash memory usage mode: RE-USE
or WRITE-ONCE, as described above.
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