Using Scream!
institution’s name, etc. The system identifier can be up to 5 characters long, whilst
the serial number cannot be longer than 4.
Sensor Type
: If the sensor attached to the digitiser is a Güralp velocity sensor, useful
seismometer functions (such as sensor locking, centring, and calibration) may be
controlled through the digitiser. The
Sensor Type
you set here determines which
functions will be available through the Scream! digitiser configuration set-up
interface or through interactive commands.
GPS Type
: The digitiser needs to be able to time-stamp accurately all data that
passes through it. It can set its clock either by receiving time signals from the GPS
satellite network using an attached Güralp GPS receiver unit, or by taking time
information from a central site (stream sync mode). In
stream sync
mode, the
digitiser expects to receive two-byte packets from the central timing source, which
may have its own GPS unit, or take signals from one of the radio time standards.
Choose the mode you require from the drop-down menu.
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 a
specified number of hours. Disabling this option keeps the GPS unit running
constantly; if you have ample power, this will give the most accurate results. You
can choose any whole number of hours for the interval.
5.1.2 Output control
The
Output control
tab allows you to configure which data streams are sent to
Scream! from the digitiser.
37
Issue U - December, 2021
