Guralp Systems CMG-CD24 - Manual (Page 68)

CMG-CD24
The calibration is disconnected the same number of minutes after the
negative edge.
component specifies which component is to be calibrated, one of Z,
N/S, or E/W.
You can alter the duration of each step using the MINUTE command,
described below.
5.6.3 RANDOMCAL
Syntax: component RANDOMCAL
Instructs the CD24 to inject a white-noise calibration signal generated
by an onboard pseudo-random number generator.
component specifies which component is to be calibrated, one of Z,
N/S, or E/W. 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.
5.6.4 MINUTE
Syntax: duration MINUTE
Sets for how long the next SINEWAVE calibration signal will be
injected, or the period of the next SQUAREWAVE calibration signal.
duration is the desired interval, in minutes. If you now issue a
SINEWAVE command, the calibration will last duration minutes; if
the next calibration command is SQUAREWAVE, a positive step of
duration minutes will be generated, followed by a negative step of a
further duration minutes.
If you do not issue MINUTE, calibration signals will default to 2
minutes. This is to avoid the sensor and digitiser inadvertently being
left in calibration mode. Issuing, e.g., 5 MINUTE will cause the next
calibration signal to last 5 minutes, but later calibration signals will
revert to a duration of 2 minutes. You will need to issue a MINUTE
command before each injection.
Because of the way FORTH works, you can insert MINUTE commands
into SQUAREWAVE or SINEWAVE commands, for example:
68 Issue C