The requirements for the final device are grouped to the three categories. Mandatory requirements are bound to be met at any cost. Some of the high importance requirements can be skipped or slightly modified, if unpredictable obstacles are found. However, they are all assumed to be completed for well being of the project. Optional requirements will be completed only if possible, given the resources will allow it.
The device under test will be referred to as \textbf{appliance}. The requirements for the final \textbf{measuring device} are grouped to the three categories. Mandatory requirements are bound to be met at any cost. Some of the high importance requirements can be skipped or slightly modified, if unpredictable obstacles are found. However, they are all assumed to be completed for well being of the project. Optional requirements will be completed only if the resources allow it.
They are also divided to a hardware part and software part. Software is easier to change than hardware and requires hardware to be run on. Software is also limited by the resources provided by the hardware. Therefore, hardware needs to be logically completed first and are also highlighted in figures \ref{f:client_node} and \ref{f:serv_node}.
@ -17,9 +17,9 @@ They are also divided to a hardware part and software part. Software is easier t
\textbf{High importance:}
\begin{enumerate}[resume]
\item Store the measured data in server's node available non-volatile local \gls{memory}
\item Completely shut the device under test off or back on
\item Indicate that the device is active (configured and working) with a \gls{led}
\item Handle maximum of 8 A currents drawn by the device under test
\item Completely shut the appliance off or back on
\item Indicate that the measuring device is active (configured and working) with a \gls{led}
\item Handle maximum of 8 A currents drawn by the appliance
\end{enumerate}
\textbf{Optional:}
@ -39,15 +39,15 @@ They are also divided to a hardware part and software part. Software is easier t
\textbf{Mandatory:}
\begin{itemize}
\item The \gls{gui} running on the web-server
\item Add, edit (configure) and remove measurement devices to/from the system
\item Present the instantaneous (real) power consumed for each device under test
\item Add, edit (configure) and remove measuring devices to/from the system
\item Present the instantaneous (real) power consumed for each appliance
\end{itemize}
\textbf{High importance:}
\begin{itemize}
\item Graphs of all measured quantities over time
\item Authentication mechanism
\item Automatic configuration of the new connected measurement devices
\item Automatic configuration of the new connected measuring devices
\end{itemize}
\textbf{Optional:}
@ -68,13 +68,13 @@ They are also divided to a hardware part and software part. Software is easier t
\newpage
\section{System design}
The first mandatory software requirement asks for a web server. It is entirely possible for every measurement device to contain its own web server. However, multiple points are requiring devices to work as a \textbf{system}. Two common system structures are \textit{centralised} and \textit{decentralised}.
The first mandatory software requirement asks for a web server. It is entirely possible for every measuring device to contain its own web server. However, multiple points are requiring separate parts to work as a \textbf{system}. Two common system structures are \textit{centralised} and \textit{decentralised}.
Decentralised (peer-to-peer) systems are harder to build but are more fail-proof. Since fail-proofness is not mentioned in the requirements, centralised system might suffice.
Using centralised system means, that the measurement devices will use one separate device, from now called the \textbf{server node}, to do most of the work on the software side. The work includes, but is not limited to, receiving the measured data, storing them, hosting the web server with the \gls{gui} containing all necessary options and information, handling the \gls{usb} or communication with a \gls{cloud} and so on. The block diagram for a server node, depicting required blocks can be seen in the figure \ref{f:serv_node})
Using centralised system means, that the measuring devices will use one separate accessory, from now called the \textbf{server node}, to do most of the work on the software side. The work includes, but is not limited to, receiving the measured data, storing them, hosting the web server with the \gls{gui} containing all necessary options and information, handling the \gls{usb} or communication with a \gls{cloud} and so on. The block diagram for a server node, depicting required blocks can be seen in the figure \ref{f:serv_node})
Where there are at least two nodes in a system, they have to communicate together in a particular way, known to both of them. The web server naturally operates over \gls{tcpip}. Therefore, same networking stack (the way of comunication), that is used for communication between the server node and user can be used to communicate to client nodes as well. \Gls{tcpip} hardware is ready to be used and is supporting a full-blown networking \gls{stack}, powering communication over today's networks.
The measurement devices, from now on called \textbf{client nodes} will consist of blocks of the remaining hardware requirements. The resulting block diagram can be seen in the figure \ref{f:client_node})
The measuring devices, from now on called \textbf{client nodes}, will consist of blocks of the remaining hardware requirements. The resulting block diagram can be seen in the figure \ref{f:client_node})
Peter Babič
8 years ago