Guralp Systems CMG-DM24 - Manual (Page 19)

Operator's guide
WRITE-ONCE
Command: WRITE-ONCE
Instructs the DM24 to stop writing data to the Flash memory when it is
full, and to switch to DIRECT mode automatically.
For example, in FIFO mode with WRITE-ONCE buffering, the station
will transmit data to you continuously, but also save it in the Flash
memory until it is full. Once full, the instrument will switch to
DIRECT mode and continue transmitting, though no further data will
be saved. This mode thus lets you define the start point of the data
held by the instrument.
3.4 Downloading stored data
If you choose a transmission mode where data is stored in Flash
memory, you will need to recover this data at a later date. You can do
this either over the serial link or using the DM24's FireWire interface.
Downloading over FireWire
To download data over FireWire, plug the disk in and issue the
command DISKMENU from the digitizer's console. The digitizer will
reply with a list of download options.
If you have not used the disk before, you will need to reset it. Resetting
the disk prepares it for the DM24 to use and sets up the DFD filing
system (see below). Press R then ENTER to reset the disk. When the
DM24 is ready, it will return to the menu.
You can also use gcfxtract or Scream! to prepare a FireWire disk.
To download all the new data held by the DM24, press N then ENTER,
or wait for 10 seconds. The DM24 will transfer any data it has
recorded since the last download and then mark this data as
transferred.
You can also download selections of data (including the entire
contents of the data store, if desired) with the DISKMENU command.
See Section 5.9, page 77, for more information.
The DM24 checks for a FireWire disk when it boots up. If there is
enough new data waiting to be transferred (by default 128 Mb), the
DM24 will automatically transfer it onto the disk. The digitizer then
updates its internal pointers to mark this data as already downloaded.
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