Guralp Systems CMG-3ESPCD - Manual (Page 68)

CMG-3ESPCD Digital Broadband Seismometer Command line interface
The arguments freq­or­period and unit together determine the frequency
of the calibration signal. If unit is HZ, then freq­or­period is taken as a
frequency, in Hz; if SECOND, then it is interpreted as a period, in seconds.
For example:
N/S 4 HZ SINEWAVE
The argument freq­or­period 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. T he
calibration signal will be automatically disconnected after 2 minutes if you
have not altered the setting using the MINUTE command, described below.
Whilst calibration is in progress, the fourth (auxiliary, or X) data channel is
switched on to monitor the returning calibration signal.
6.5.2 SQUAREWAVE
Syntax: component SQUAREWAVE
Instructs the digitiser 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). The calibration
is disconnected the same number of minutes after the negative edge.
The argument component specifies which component is to be calibrated, one
of Z, N/S, E/W, or X. Some sensors use only the Z calibration loop for all three
components. You can alter the duration of each step using the MINUTE
command, described below.
Whilst calibration is in progress, the fourth (auxiliary, or X) data channel is
switched on to monitor the returning calibration signal.
6.5.3 RANDOMCAL
Syntax: component RANDOMCAL
Instructs the digitiser to inject a white-noise calibration signal generated by an
on-board pseudo-random number generator.
The argument component specifies which component is to be calibrated, one
of Z, N/S, E/W, or X. Some sensors use only the Z calibration loop for all
three components.
The calibration signal will be automatically disconnected after 2 minutes if
you have not altered the setting using the MINUTE command, described
below.
Whilst calibration is in progress, the fourth (auxiliary, or X) data channel is
switched on to monitor the returning calibration signal. The pseudo-random
MAN-C3E-0002 68 Issue B - November 2013