Observation, analysis, improvement
The SCADA part of an EME control system provides numerous statistics and functions that can be used to analyse and improve the process. All interventions are recorded and alarms and diagnoses are registered in a log file. The operator always has complete control of the situation and, in the event of a fault, EME can evaluate these files and offer targeted assistance.
The charge analysis can display the diagnosis of the dosing accuracy (see figure 1). This is selected by choosing one component in the detail window and refers to the chosen raw material within this batch composition. The deviation between set point and actual values are displayed for the time period specified. The tolerance deviations are also shown, as are the new values that are calculated each time for the fine flow optimisation. The weight of the scale at the beginning of the dosing process is also displayed. This can assist in identifying any caking in the scale receptacle.
A second figure (figure 2, left) shows the normal distribution of the weighing tolerance, based on several thousand datasets. In this example 50 % of the tolerance values were 0,0 kg and 1 % were 0,2 kg. The second diagram (right) shows the cumulative distribution function for the same selected time period and number of datasets. This diagram can be used to determine the proportion of the datasets that will be within a specific tolerance range.