Guralp Systems CMG-DCM build <10,000 - Manual (Page 122)

CMG-EAM (Platinum Firmware)
downloads all recorded files, powers down the disks and then
disconnects.
Note the use of ssh's tilde ('~') escape followed by + to
suspend the ssh session and return to the calling PC, in order to run
the scp command with the disk still mounted. The fg command
(foreground) returns control to the ssh session.
122 Issue C