Guralp Systems CD1.1 - Manual (Page 5)

Operator's Guide
1 Introduction
The Güralp CD1.1 tool suite for the Platinum firmware of CMG-
EAM, CMG-DCM and CMG-NAM hardware consists of four
modular components that can be used together to implement
either a single-station CD1.1 sender or a cross-array sender,
coalescing subframes from multiple stations into a single
outgoing data frame for the entire array.
When building an array, each individual element of the array is
actually a fully independent CD1.1 sender in its own right.
Supported features include fully-conformant status fields (State
of Health or SoH), flexible tamper line support, Canadian
compression and optional hardware authentication. Back-fill
capacity is limited only by the size of the fitted flash module or
disk array.
The CD1.1 tool suite runs in parallel to other programs, so it is
possible to use other data formats simultaneously.
1.1 Platinum architecture
Platinum firmware runs natively on CMG-EAMs and CMG-NAMs.
It can also be installed on the earlier CMG-DCM units. Platinum
firmware is based on the Linux operating system, which
provides a robust, familiar and flexible platform for the
protocol-handling and configuration software.
Seismic protocols are handled by a number of configurable
software modules, which run as user-space programs. They
can, on the whole, be stopped, reconfigured and started
independently of each other. The whole system is managed by
a flexible and extensible configuration interface which is
accessible in near-identical format from either the web
interface or a character-based terminal, connected either
serially or over a network.
The majority of the protocol-handling features of Platinum are
based on Güralp Data Interconnect, or GDI. The gdi-base
module serves as the central data interchange, accepting data
from a wide variety of input protocol-conversion modules,
buffering and re-ordering incoming data where necessary,
associating samples with their meta-data and providing data
via a consistent interface to the output protocol-conversion
modules.
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