Guralp Systems CMG-DCM build <10,000 - Manual (Page 255)

Acquisition Modules and Platinum Firmware Technical operation
gain *gains
where gain is one of 1, 2, 4, 8, 16, 32 or 64. For example, to select ×8 gain
on all channels, enter the command
8 *gains
The digitiser must be rebooted before the change will take effect.
To set the gain for an individual channel, enter the command:
channel gain *gain
where channel is one of 0 (vertical), 1 (North/South), 2 (East/West) or 3
(auxiliary/calibration). On seven channel digitisers, this parameter can also
be one of 4 (vertical), 5 (North/South) or 6 (East/West), referring to the
components from the second instrument. gain is one of 1, 2, 4, 8, 16, 32 or
64. For example, to select ×16 gain on just the vertical channel, enter the
command
0 16 *gains
The digitiser must be rebooted before the change will take effect.
Software developers working with GCF packets can decode the selected gain
setting from the GCF header as follows:
If the most significant bit of the System ID is zero, variable gain is not used. If
the most significant two bits of the System ID are 10 or 11, the next three bits
encode the gain, using this code:
Bits 2, 3 & 4 Gain
000 not fitted
001 ×1
010 ×2
011 ×4
100 ×8
101 ×16
110 ×32
111 ×64
15.1.3 USB operations
The Cylindrical Digitiser can behave as a USB storage device (via the GPIO
connector) or as a USB host (via the USB connector).
MAN-EAM-0003 255 Issue E - February 2014