This paper deals with the problem of simulating
the sequence of events in the communication through one of the
most commonly used fieldbuses: Profibus-DP. Control systems
using a fieldbus or any other kind of shared communication
medium, are known as Networked Control Systems. A detailed
description of the operation of Profibus, when transmitting a
signal in a round trip between slave and master devices, is
included. This operation is characterized with a collection of
parameters whose values are determined by the practical
implementation of the network. A simulation model, using
Matlab/Simulink is built to emulate the behavior of the real
system. This model has been validated, processing the
transmitted signal and using histograms to compare the results
obtained from real and simulated transmission.