Telemetry
The
"Internet of Things"
not on requires methods for describing objects, but
mechanisms for sensing and controlling the physical
environment. The Physical Markup Language supports
this capability by providing specifications for establishing
and interpreting sensory information.
Under
the broad term of telemetry
, many physical systems require continual monitoring
and support. From the flight control systems on the
Space Shuttle to a heart-lung machine in a hospital,
accurate, real-time information is vital to their
effective operation.
As
we move toward a great degree of connectivity and
increasingly networked physical systems, a reliable
method for creating and maintaining sensor communication
becomes that much more important.
The
traditional protocols of the World Wide Web, such
as the Hyper Text Transport Protocol (HTTP), work
well for static information in fixed databases, but
not for dynamic, distributed data communication. There
are, however, many protocol adpated for this purpose.
We
include in this version of the Physical Markup Language
a simple data structure to reference these protocol
and to provide high level interpretation of the incoming
data streams.
Data
Stream
We
introduce that datastream
element as a high-level interface and specification
to lower-level data protocol. The datastream
element includes a host
and a port
element describing the network host name and data
port from which the data will be received. These
corresponde to the usual definitions of Internet
Hostname and Network Port address.
Following
the host
and port
elements, are one or more msr
(mearment) elements, indicating the number, units
and offsets of incoming data stream. For this version
of PML, we assume data is encoded as 32-bit floating
point numbers.
