Extended trend indicator for process data and secondary alarms

A non-transitory computer-readable medium encoded with a computer program for a visualization system, the computer program comprising machine code processed by the visualization system;

• wherein, upon processing the machine code with a selection of an item of process data and specification of an associated display period of time by at least one operator of a process control system which controls and monitors an industrial technical installation and which acquires the item of process data at each acquisition point in time and archives each item of process data as a history for the predetermined display period of time, the visualization system requests the history of the selected item of process data and outputs the associated temporal curve as a graphic comprising a number of process data points to the at least one operator, wherein, upon processing the machine code, the visualization system determines the respective process data point with reference to values of the selected item of process data of a respective acquisition period of time which is characteristic for the respective process data point, the respective process data point comprising a mean value or a median value of the process data of the respective acquisition period of time;
• wherein, upon processing the machine code, the visualization system also determines at least one of a minimum value and a maximum value of values of the selected item of process data for the respective process data point during the respective acquisition period of time;
• and wherein, upon processing the machine code, the visualization system always then displays a secondary alarm together with the respective process data point comprising the minimum and maximum values and the mean or median value if at least one of (i) the minimum value which is determined for the respective data point is below a predetermined minimum value and (ii) the determined maximum value exceeds a predetermined maximum value, the secondary alarm representing an alarm which is not set by the process control system but rather is set by the visualization system;
• wherein the control system, automatically and cyclically acquires the process data;
• and wherein the visualization system is instructed by the control system, such that visualization system cyclically sets and displays the secondary alarm, based on the process data, when the one or both checks are positive.

A visualization system, comprising:

• a processor;
• and memory;
• wherein the visualization system is configured, during operation, to:
• acquire at each acquisition point in time, process data and archive the acquired process data as a history;
• select an item of the process data;
• request the history of the selected item of process data and output an associated temporal curve as a graphic comprising a number of process data points to the at least one operator, upon the selection of an item of process data and a specification of an associated display period of time by at least one operator of the process control system for the predetermined display period of time;
• determine a respective process data point with reference to values of the selected item of process data of a respective acquisition period of time which is characteristic for the respective process data point, the acquisition period of time comprising a plurality of acquisition points in time and the respective process data point comprising a mean value or a median value of the process data of the respective acquisition period of time;
• determine at least one of a minimum and a maximum of values of the selected item of process data for the respective process data point during the respective acquisition period of time;
• check whether at least one of (i) the minimum value which is determined for the respective process data point is below a predetermined minimum value and (ii) the maximum value which is determined exceeds a predetermined maximum value;
• and display a secondary alarm together with the respective process data point comprising the minimum and maximum values and the mean value or the median value, when one or both checks are positive, the secondary alarm representing an alarm which is not set by the process control system but rather is set by the visualization system;
• wherein the control system, automatically and cyclically acquires the process data;
• and wherein the visualization system is instructed by the control system, such that visualization system cyclically sets and displays the secondary alarm, based on the process data, when the one or both checks are positive.