Measurement documents

In SAP applications, measured values describe a certain status of a production system at a certain time in the process flow. Any variable existing in zenon can be defined as a measurement document. This allows handing over protocol-independent data from the real time process to the superordinate management level.

In many cases, it is better to aggregate process data already on the process level and then pass it on in a condensed format to the SAP system for analysis. For example, zenon delivers average values and other statistical values calculated from value series to the SAP system. This avoids overloading the management system with raw data.

Measured values and counter readings are recorded cyclically and stored as measured documents for a measuring point in the SAP system. The properties of the measuring point in the SAP system determine whether it is a measured value or a counter. The current variable value is used as the value of the measurement document.

Several measuring points can be defined for every technical spot or every piece of equipment in the SAP system. During the definition of the measuring points, you can configure whether the measuring point shall continue a measured value or a counter reading. Counter readings must have monotonously rising values, i.e. every new value you enter must be equal to or higher than the previous value.

Measured values and counter readings of measuring points are passed on to the SAP system by means of so-called "measurement documents".

In the control system, measured values are recorded according to schedules. For every schedule, you can define the weekdays and the times at which measured values shall be recorded. A schedule can be executed either daily or only on specific weekdays. Furthermore, you can define a starting time and an ending time as well as an interval for every schedule. Between the starting time and the ending time, the measured values of the linked variables in the specified interval will be recorded.

You can link a number of values with every schedule. Every time the schedule is executed, the current values of the variables will be read out and a measurement document for every variable value will be created in the SAP system. Every measuring point has a unique number that must be put down in the measurement document. The resource label of the linked variables is used to determine the number of the measuring point.

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The control system variables and the SAP measuring points are mapped via the ID of the measuring point in the SAP system. This unique consecutive number must be entered in the resource label of the variables in the control system.