Guralp Systems CMG-DCM - Manual (Page 30)

CMG-DCM Data Communications Module
DCM. If it is not shown, you may have to 'unfold' the tree to
reveal it. The digitizer(s) attached to the DCM will appear
underneath the entry for the serial port, and you can configure
them from within Scream!. See Scream!'s documentation for
more details.
8. If no digitizer is shown, it may be that your software is not
configured correctly for the serial link. As supplied, the DCM
uses a baud rate of 115200 on its
CONSOLE port, with 8 data
bits, no parity bits and 1 stop bit, and no flow control.
For more information on how to use Scream! to display and manage
data streams, please see Scream!'s own documentation or the extensive
on-line help.
Accessing the DCM command line through gcf_out
The gcf_out service provides a command-line terminal designed to be
compatible with Güralp Systems' SAM serial storage device. To access
this terminal from Scream!, right-click on the DCM's icon and select
Terminal.... You will see a banner like
DCM DCM CRSM Command Mode
0 blocks in buffer | 16360 blocks free
The SAM commands you can use are described in the SAM Operator's
Manual.
You can also log in to the DCM's Linux operating system through the
terminal. Enter the command
GETTY
and press ENTER. You will be presented with the login: prompt.
If you are not using Scream!, and cannot make the unit enter SAM
compatibility mode, you can interrupt the GCF data stream and drop
straight to the login: prompt by connecting direct to the serial port
and typing
forcegetty
It may take several attempts for this to succeed.
Sensor arrays
Another possible reason for setting the DATA OUT port's service to
gcf_out is to allow several DCM units to work together and aggregate
30 Issue F