Guralp Systems CMG-DM24 - Manual (Page 64)

CMG-DM24
The special value, NORMAL COMPRESSION, returns the setting to its
default value, equivalent to 8BIT 250 COMPRESSION.
LOWLATENCY
Syntax: LOWLATENCY
This is a special mode for applications requiring lower sample rate
data in as close to real time as possible. In this mode, the digitizer
takes a 200 samples/s stream and passes it through low-pass and
decimation filters internally, before exposing it as a 20 samples/s
stream at an increased rate of 1 block per second.
To enable low latency mode on all three components, first use
SAMPLES/SEC to set Tap 0 to 200 samples/s, then issue the following
commands:
NORMAL COMPRESSION
0 7 CONTINUOUS
0 1 BANDPASS
LOWLATENCY
7 TRIGGERS
If you want to enable low latency mode on some components only,
replace the 7s above with another value (e.g. 1 = Z, 2 = N, 4 = E).
To disable low latency mode, issue
0 1 BANDPASS
0 TRIGGERS
When LOWLATENCY is active, the TRIGGERS and BANDPASS
commands have special meanings. Because of this, the STA/LTA
triggering function is disabled. You can still use LEVEL triggering if
you require (see below).
SETDSS
Syntax: output-spec SETDSS
This command alters the way the DM24 outputs its status streams.
In normal operation, the DM24 stores lines of status information until
it has filled a 1K GCF block. For low latency applications, however,
status information is required more frequently. In this mode, the
DM24 will output a status block every minute. This mode is required
by the DSS server distributed with Güralp Systems' CMG-DCM.
64 Issue N