Chapter 6. USB Operations

The CMG-3EX-EAM can function as both a storage device, available for access from a USB connected PC, and as a USB host, writing to external USB storage devices such as memory sticks and USB disks.

When used as a USB storage device, the GPIO connector is employed. When acting as a host, the USB connector is used. The pin-outs of both these connectors are given in the appendices of MAN-EAM-0003.

6.1 USB device mode

The CMG-3EX-EAM is fitted with an internal Flash memory device which is accessible via USB. It can be written to by selecting “Internal USB storage” from the “Recording destination” drop-down menu on the “Disk recording” menu (see section 11.2 of MAN-EAM-0003).

When a USB host, such as a laptop or PC, is connected to the GPIO port, internal circuitry detects the USB power and automatically connects the Flash memory to the USB socket, causing it to behave identically to a standard USB memory stick.

When no power is detected at the USB port, the Flash memory is available to the system as if it were a standard removable disk. All of the disk recording options described in section 11 of MAN-EAM-0003 will apply to this device.

6.2 USB host mode

If a USB storage device is connected to the USB port, it will be mounted under /media. It can be used to store seismic data by selecting “External USB drive on mil-spec connector” from the “Recording destination” drop-down menu on the “Disk recording” menu, described in section 11.2 of MAN-EAM-0003.