  We implement a recently proposed event-triggered networked MPC approach on
industrial hardware to analyze its practical relevance. There exist several
alternatives for such an implementation that differ with respect to the
distribution of computational load between local and central nodes, and with
respect to network bandwidth requirements. These alternatives have been
analyzed theoretically before, but when implemented it becomes evident that
their usefulness cannot be predicted based on theoretical considerations alone.
It is the purpose of the present paper to account for both practical and
theoretical aspects in determining which alternative is most appropriate for an
implementation on industrial hardware. The smallest possible bandwidth is known
to result for a variant in which only the active set of constraints is
transmitted from the central to the local nodes. Since local nodes must
determine the control law from the active set in this case, which requires
matrix inversions, an unattractive computational cost results at first sight.
Somewhat surprisingly, the computational cost scales practically linearly in
the problem size when implemented. We confirm this result with a more detailed
theoretical complexity analysis than given in previous papers. All results are
illustrated with data obtained with an implementation on industrial hardware
components.
