Guralp Systems CMG-6TD - Manual (Page 88)

CMG-6TD Command-line interface
7.4.3 COMPRESSION
Syntax: bits size COMPRESSION or NORMAL COMPRESSION
Sets the maximum amount of compression to use. Greater compression
means the digitiser outputs data more efficiently, so more can be transmitted
over a link with a given bandwidth. However, compressing streams uses
processor power and can increase data latency.
The digitiser compresses data without loss, so compression is most effective
when the data contain relatively little information. In most cases, when a
seismic event occurs, the digitiser will need to decrease the compression
level.
bits can be one of 8BIT, 16BIT and 32BIT. 8BIT (the default) is the
maximum amount of compression; 32BIT denotes no compression.
size determines the maximum number of data samples in a GCF block. This
must be between 20 and 250; the default is 250.
GCF blocks must be a whole number of seconds long. If you set size to a very
small value, so that size samples is less than one second for some streams,
the digitiser will output one block every second for those streams, ignoring
the value of size.
Thus, if you issue 32BIT 20 COMPRESSION, streams with a sample rate of 20
samples/s and higher will output one block per second, whilst lower rate
streams will output 20-sample blocks: every 5 seconds for 4 samples/s data,
etc.
The special value, NORMAL COMPRESSION, returns the setting to its default
value, and is equivalent to 8BIT 250 COMPRESSION.
7.4.4 ETHER
Syntax: ETHER ENABLE | ETHER DISABLE
For units with integrated networking hardware, ETHER DISABLE turns off the
power to the embedded Lantronix networking module, which significantly
reduces power consumption if the networking support is not required. The
command ETHER ENABLE turns the networking module back on.
7.5 Triggering
7.5.1 TRIGGERS
Syntax: components TRIGGERS
Selects which component or components can generate a trigger. Only these
components will be examined by the triggering algorithm.
MAN-T60-0002 88 Issue F - February 2014