Guralp Systems CMG-DM24 - Manual (Page 45)

Operator's guide
System
When the Control window is first opened, it will be showing the
System pane.
Sensor Type: If the sensor attached to the digitizer is a Güralp velocity
sensor, you can send control commands to it from the Mass Control tab
(see below). Which functions are available on this tab depends on the
Sensor Type you have set here.
If you change the Sensor Type, you may have to Apply the change,
close the Control window, and open a new one to access the Mass
Control options.
Enable GPS power cycling: If you are using a GPS unit to receive time
signals, but do not experience significant drift in the system's clock
(for example, in a stable-temperature environment), you can save
power by selecting Enable GPS power cycling. With this option in use,
the GPS time is only checked at intervals of the specified number of
hours and the GPS receiver is powered down in between checks.
When the time is checked, the GPS receiver is powered up for as long
as it takes to obtain a satellite “fix” and both synchronize and stabilise
the internal clock. Under extreme adverse conditions, ensuring the
internal clock is stabilised may take longer than the power cycling
interval, in which case the GPS receiver will remain powered up
throughout.
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