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of small changes is not always this radical, but this example shows how hard it can be to
predict the generated code.
With small and simple tasks, the MATLAB function block generation works very well,
but it requires always a very careful examination of the generated code to make sure that
the code is somewhat reasonable. One good example of the MATLAB function block is
presented in figure 44. With a simple if structure we can easily replace the Merge block
which is not allowed in the current version of PLC Coder. Without the Merge block the
Simulink’s if-structure is somewhat impossible to use.
Figure 44. With a simple MATLAB function block we can easily replace the unsupported
Merge block.
8.1.3 Multiple task execution time levels
Handling the different time levels is crucial in any software development work. The logic
controllers have quite often multiple execution time levels, which are usually structured
with either timer variables or with IEC-61131 tasks. PLC Coder has a full support for
multiple time levels, which are carried out by using IF-statements and additional timer
variables called ‘plc_ts_counter’.