Guralp Systems CMG-DM24 - Manual (Page 71)

Operator's guide
POLARITY
Syntax: 0 POLARITY or 1 POLARITY
Sets the sense of the Trigger In pin on the DATA OUT port.
With 0 POLARITY set, the Trigger In pin is active low, i.e. a trigger will
be generated if this pin is connected to ground. 1 POLARITY switches
the pin to be active high.
You must issue TRIGGERIN ENABLE to enable external trigger input.
5.7 Calibration
SINEWAVE
Syntax: component freq-or-period unit SINEWAVE
Instructs the DM24 to inject a sine-wave calibration signal, starting on
the zero crossing.
component specifies which component is to be calibrated, exprressed
as one of Z, N/S, E/W, or ALL. Some sensors use only the Z calibration
loop for all three components.
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 Herz; if SECOND, then it is interpreted as a period, in
seconds. 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 SECOND, you must specify it as 2 HZ instead.
The calibration signal will be automatically disconnected after 2
minutes (unless you have altered the setting using the MINUTE
command, described below).
Whilst calibration is in progress, the fourth (auxiliary, or X) data
channel is switched to monitor the returning calibration signal.
SQUAREWAVE
Syntax: component SQUAREWAVE
October 2009 71