Guralp Systems Strong Motion - Manual (Page 7)

Güralp Systems Ltd.
should improve the quality of strong motion results.
2.4 Enable strong motion mode
The CMG-DM24 has a flexible system of output taps which can
be used to choose which sample rates are transmitted. Strong
motion mode requires the first tap be set to 200 samples per
second. The configuration below transmits 100sps continuous
data, which you can alter as you please. It also transmits the
20sps low-latency data, which is filtered differently (see the
section below on low latency data). The low-latency data is
always at 20sps. The output taps must be configured as follows
for correct operation:
200 100 20 10 samples/sec
200 100 20 10 samples/sec ok_A808
The steps below enable lowlatency mode, and turn on the
20sps low latency data. Change “$77 triggers” to simply “7
triggers” for a one-instrument system.
lowlatency
Tap0 200 s/s Low Latency mode ( 20s/s ) ok_A808
$77 triggers
Tap0 200 s/s Low Latency mode ( 20s/s ) ZC NC EC ZC NC EC
ok_A808
LLstreams enable
Low Latency Data Streams enabled ok_5E63
Transmission of the low latency 20sps streams is controlled by
the “LLstreams” command. In v.103 build 70, low latency is
disabled by default, and must be explicity enabled with the
above command. It can be disabled again with “LLstreams
disable”.
Next, the continuous data transmission is configured. The first
hex code below tells the DM24 to output continuous data from
the second tap on both instruments. For a one-instrument
digitiser setup, this should be changed to 00070000. The
second hex code turns off the multiplexor channels, which are
not used for strong motion instruments.
set-config
Hex code to select taps {00770000} 00770000
Hex code to select mux channels {0000} 0000
Tap0 200 s/s
Tap1 100 s/s Continuous: Z2 N2 E2 Z2 N2 E2
Tap2 20 s/s
Tap3 10 s/s ok_A808
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