Analysis of the queue buffer transmitting device through the channel multiple access with guaranteed delivery of packets
The article deals with the modeling of the process of data transmission from sensors in the industrial production of vinyl acetate. The data packets are transferred from the sensors to the control system and the control effect is directed to the temperature regulators of the gas-vapor mixture, the vapor pressure of the refrigerant. oxygen consumption and return acetic acid consumption by industrial Ethernet protocols over a multiple access channel with carrier control and detection of CSMA / CD collisions (Carrier Sense Multiple Access with Collision Detection). The main bottleneck of the system is a limited sensor transmission buffer, which can cause data loss when it overflows, and due to improper regulatory impact. Mathematical modeling of the transmission process was carried out according to the scheme of the Markov process with continuous time and discrete states. The transmitter transmission buffer model was constructed on the basis of the state graph, each state is displayed by two elements [i, j]: i is the number of packets in the queue waiting to be sent; j - number of sent packets pending confirmation. A column of Kolmogorov equations was constructed. The solution was carried out numerically using the Maple mathematical package (Runge-Kutta-Felberg method 4-5th order). Based on the data obtained after modeling, we can conclude that the average packet transmission time, the number of lost packets with different bandwidth and channel load transfer. The adequacy of the model was confirmed with the help of experimental data, it was tested by the Fisher criterion, and the hypothesis at the level of significance of general variances was adopted. The model allows calculating the static and dynamic characteristics of the queue on a network device (they are important for calculating the functioning of the network in real time) systems for monitoring and controlling the production of vinyl acetate