Guralp Systems CMG-CD24 - Manual (Page 67)

Operator's Guide
Enabling external trigger output allows you to trigger other equipment
through a relay contained within the CD24 whenever it triggers. The
CD24's digital output port contains two pins (Trigger out, common and
Trigger out, normally-open) which are connected when it triggers. In
particular, you can connect a second digitiser with TRIGGERIN
ENABLE in effect, in which case triggered data from both instruments
will be transmitted whenever the CD24 triggers.
If a CD24 has both TRIGGERIN ENABLE and TRIGGEROUT ENABLE in
effect, only triggers which the CD24 itself has generated will be output.
Triggers received through the Trigger in port will cause the CD24 to
output triggered streams, but will not be passed on to other digitisers.
5.6 Calibration
5.6.1 SINEWAVE
Syntax: component freq-or-period unit SINEWAVE
Instructs the CD24 to inject a sine-wave calibration signal, starting on
the zero crossing.
component specifies which component is to be calibrated, one of Z,
N/S, or E/W.
freq-or-period and unit together determine the frequency of the
calibration signal. If unit is HZ, then freq-or-period is taken as a
frequency, in Hz; if SECOND, then it is interpreted as a period, in s. For
example:
N/S 4 HZ SINEWAVE
freq-or-period must be an integer; if you want to specify a period
of, for example, 0.5 s, you should specify it as 2 HZ instead.
The calibration signal will be automatically disconnected after 2
minutes if you have not altered the setting using the MINUTE
command, described below.
5.6.2 SQUAREWAVE
Syntax: component SQUAREWAVE
Instructs the CD24 to inject a square-wave (step function) calibration
signal, consisting of a positive step on the start of the next clock
minute, followed by a negative step some minutes later (by default, 2).
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