Guralp Systems CMG-DCM - Manual (Page 41)

Operator's guide
viewer window.
If you do not want to use the DCM's Web site, you can find out the
number of GCF blocks the DCM has received with the command
gnblocks. Each serial port will be listed, with its name, number, key
number and device name (as for serialmap) but including the
number of blocks received on that port:
Key 0x007005: Blocks 3287 (Port 5, name Port A (COM6),
device /dev/ttyS2, baud 9600)
The DCM is not receiving any data streams.
•
Check the connection between the digitizer and the DCM by
trying to log in to the digitizer's console using any of the
methods described in Section 3.4 (page 33.) Press ENTER a few
times to initiate communication.
•
If the digitizer gives an ok prompt when you press ENTER, check
that you have configured the digitizer to output real time data
streams. Streams will not appear until a whole GCF block (1024
bytes) is ready for transmission, so a 5 sps stream may not
appear until the digitizer has been working for 4 minutes. In
addition, you can configure a digitizer to output only triggered
streams, in which case it will not appear until a trigger occurs.
(There is an exception to this: if you have put the digitizer in the
FILING or DUAL filing mode, it will send heartbeat messages to
Scream! clients every so often. The DCM will not show these
messages in the Data Viewer.)
•
If the digitizer does not respond when you press ENTER, or
produces garbage, check that the DCM is using the same baud
rate as the digitizer. By default, digitizers use a baud rate of
9600, with 8 data bits, no parity bit and 1 stop bit, and no flow
control. To change the DCM's settings,
exit the terminal
program, and either
•
access the DCM Web site, click on the Configure – Port link in
the serial port table, and change the settings, or
•
issue configuration commands such as
serial.5.service gcf_in
serial.5.baudrate 9600
serial.5.handshaking none
To obtain the port number (here 5) corresponding to a named
port, use the command gnblocks.
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