architecture/commim.tex

   1 The \iTasks{} server can send two types of messages. The first and most
   2 important type is sending a new task to the server. Tasks are dynamically sent
   3 to the microcontroller, this means that the engine in itself does not do
   4 anything without it getting a task first from the server. When a task is sent
   5 the microcontroller acknowledges the message by sending the associated task
   6 identification number back to the for the server to use in the future.
   7 The second task is sending SDS specifications to the engine to tell the engine
   8 what type of SDS will be used in the tasks so that it can be allocated. The
   9 message structure for sending a task is shown in Table~\ref{tbl:tasksend} and
  10 the message of sending an SDS specification is shown in
  11 Table~\ref{tbl:sdsspec}.
  12 \begin{table}[ht]
  13         \centering
  14         \begin{tabular}{ll}
  15                 \toprule
  16                 Bytes & Description\\
  17                 \midrule
  18                 \multicolumn{2}{c}{\textbf{Request}}\\
  19                 $1$ & Task send code \verb#'t'#\\
  20                 $2-3$ & Frequency in number of milliseconds as a 16-bit integer\\
  21                 $4-5$ & Length of the bytecode 16-bit integer\\
  22                 $n$ & Bytecode for the task\\
  23                 \midrule
  24                 \multicolumn{2}{c}{\textbf{Response}}\\
  25                 $1$ & Task numeric identification\\
  26                 \bottomrule
  27         \end{tabular}
  28         \caption{Message format for sending a task}\label{tbl:tasksend}
  29 \end{table}
  30
  31 \begin{table}[ht]
  32         \centering
  33         \begin{tabular}{ll}
  34                 \toprule
  35                 Bytes & Description\\
  36                 \midrule
  37                 \multicolumn{2}{c}{\textbf{Request}}\\
  38                 $1$ & SDS send code \verb#'s'#\\
  39                 $2-3$ & SDS length as a 16-bit integer\\
  40                 $2-3$ & Value of the SDS identifier\\
  41                 \midrule
  42                 \multicolumn{2}{c}{\textbf{Response}}\\
  43                 $1$ & SDS numeric identification\\
  44                 \bottomrule
  45         \end{tabular}
  46         \caption{Message format for sending an SDS specification}\label{tbl:sdsspec}
  47 \end{table}