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DUECA/DUSIME
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Making the actual programs
In the end, we want to run a simulation, in real-time on a slew of different computers. What is needed is a program that does the simulation. Now the previous sections explained how to set up a data flow diagram for a simulation, and how to implement modules in DUECA/DUSIME. What remains to be done is the creation of some sort of "main program", or in fact several main programs, one for each node, and combining all modules into executables for each of these nodes.
In DUECA, these two steps are needed, but they are done in reverse order. First we "throw together" all modules and the code from the DUECA library, and in a second step the "main" program is made. This main routine is not in C++, but in scheme, and it is the script that describes the construction of the simulation model.
In a first step, it helps to get your modules together. Consider the MMSLabStick module of the example. This module depends on some IO code to communicate with the A/D and D/A conversion cards that drive the stick hardware, it uses a class that is not a module (the PassiveManipulator class, not further elaborated here) that does the model calculations, and all this is combined in the MMSLabStick module, which does the interfacing with DUECA, calls the stick IO and calls the PassiveManipulator class to do the simulation.
No I recommend (but you may disagree here, and provide your own solution), to keep all code for a module in a single directory, and, in an intermediate step, link an object file with all this code. A template Makefile for making a module object file can be found in the DUECA distribution. Now, when everything works, typing "make" in that directory gives you a file "module.o" with all code for the module in it.
The next step is combining all your module.o files and the DUECA/DUSIME library code into an executable file. My proposal is again to create a directory for the program, and make the directories for the modules all sub-directories for this directory. The template Makefile for making a DUECA executable can be found in the DUECA distribution. Now, when everything works, typing "make" in that directory gives you an executable "dueca_run.x".
The peculiar thing about DUECA is that the executable is just a collection of modules. Running the executable, without providing additional data, cannot produce sensible output. Two configuration scripts, described in the Section on configuration files determine the behaviour of your executable. The first one "dueca.cnf" describes how the executable in a node should interact with the executables in other nodes, and the second one, "dueca.mod" describes the composition of the simulation.