Guralp Systems CMG-DM24 User Manual

Page 68

CMG-DM24

For example, 15 20 20 20 STA will calculate long-term averages

over 15 seconds for the Z component, and over 20 seconds for the N, E
and auxiliary components.

If you issue STA with only one argument, it is used for all four

components. For example, 5 STA will calculate averages over 5
seconds for all components.

RATIOS

Syntax: Z-ratio N-ratio E-ratio X-ratio RATIOS

Sets the ratio of STA to LTA above which a trigger will be declared in
the STA/LTA triggering algorithm.

Z-ratio, N-ratio, E-ratio and X-ratio are the threshold ratios

for the Z, N, E, and auxiliary components respectively. If a component
is not considered by the triggering algorithm (see TRIGGERS, above),

any value you specify here for that component will be ignored.

For example, 4 10 10 10 RATIOS will cause the DM24 to trigger if
the STA/LTA ratio is above 4 for the Z component, or above 10 for any

of the remaining components.

The arguments to this command must be integers. If you want to
specify a fractional ratio, use the command FRATIOS instead.

FRATIOS

Syntax: Z-ratio N-ratio E-ratio X-ratio FRATIOS

Sets the ratio of STA to LTA above which a trigger will be declared in
the STA/LTA triggering algorithm.

This command is exactly the same as RATIOS, except that its

arguments are divided by 10 before being entered into the system. For
example, 25 100 100 100 FRATIOS will cause the DM24 to trigger

if the STA/LTA ratio is above 2.5 for the Z component, or above 10 for
any of the remaining components.

BANDPASS

Syntax: tap filter BANDPASS

Tells the DM24 which tap to use for STA/LTA triggering calculations.

Issue N