Guralp Systems CMG-DCM - Manual (Page 42)

CMG-DCM Data Communications Module
•
If the digitizer is not responding at all, check the power supply
to the digitizer and the cable between it and the DCM.
The DCM is receiving streams, but they do not contain any data.
If the data you see is zero:
•
Increase the Y axis scale using the icon in
Scream!'s Waveview window or the corresponding icon in the
DCM's Data Viewer.
•
Check the mass position outputs to see if the masses are locked.
A properly unlocked and centred mass should show a mass
position within 1000 counts of zero; a locked mass will give a
value greater than 32,000 (or less than −32,000) counts. If your
sensor has remote mass locking, you can unlock the masses by
navigating to Actions Digitizer setup → and clicking Unlock
sensor.
Locking or unlocking the sensor mass typically takes several
minutes to complete.
•
Check the connection between the sensor and digitizer and try
again.
If you cannot see the data in the stream, remove any constant offsets
by clicking on the Zero streams icon
in Scream!'s Waveview
window or the DCM's Data Viewer.
The DCM receives streams, but gaps appear in the data some
minutes after boot-up.
Check that the baud rate between the digitizer and the DCM is
sufficient for all the data streams you want to transmit. If it is not, the
digitizer's output buffer will gradually fill up until no more data can be
stored. Increase the baud rate of the digitizer through the DCM (or
using Scream!),
then set the baud rate of the DCM's input port to the
same value.
If you are using triggered output streams, be especially careful to allow
a high enough baud rate to transmit data from all possible output
streams simultaneously, or you will observe gaps when an event
triggers the digitizer.
42 Issue F