Chapter 5. Data flush control

The CMG-3EX-EAM has an internal ring-buffer for storing seismic data. If an external storage device is connected and configured for data storage, the CMG-3EX-EAM will leave it powered down for most of the time, in order to conserve energy. Periodically, the CMG-3EX-EAM will power up the external storage device and flush the data from the ring buffer to it. (To configure an external storage device for use in this way, see Section 11.1 of MAN-EAM-0003.)

When data need to be retrieved, e.g. at a site visit or at the end of a deployment, a manual flush to storage should be initiated in order to ensure that the most recent data are written to the external device. This process can be initiated using the yellow “flush” button on the instrument's lid.

To start a flush, hold down the yellow flush button then press the black enable button for approximately 10 seconds. The flush LED should now illuminate to indicate that the transfer is in progress.

If the LED remains illuminated for only a few seconds, the flush has failed; the EAM module will retry after 60 seconds (and will retry up to three times before aborting).

When the flush is complete, the LED will extinguish. It is now safe to remove the external storage device.

Flushing data using the lid controls it identical to the web interface's 'flush' command and transfers (from flash to external storage) all data that have been recorded since the last transfer was carried out.