Configuring the Time Axis
A trend diagram displays the progression of variable values over time. For this purpose, values were stored in the Trend Recording object for each timestamp. This is the data basis for the trend diagram, which shows the time in the X-direction and the values in the Y-direction.
You can configure the labels of the time axis (X-axis) in the Trend element in the Tick mark labels property.
By default, the time axis is labeled in absolute terms with date and time on two lines. This display method takes up a lot of space. You can customize the label by displaying the relative time with respect to the start of the recording (duration). Moreover, you can use the properties in Internationalization (format strings) to provide a specific format definition to the timestamp. With the Omit irrelevant information in timestamps property, you can minimize the labeling everywhere. Then, for example, the date is output only one time at the beginning of the time axis.
Labeling the time axis
Tip
The time stored in the trend recording are in the UTC time zone. If the time is displayed in the trend of the visualization element, then the timestamps are converted to the local time zone of the operating system of the PLC.
Change the time zone in the operating system if the times in the trend diagram are not in the zone that you need.
Requirement: A Trend element is configured in the visualization.
Select the trend element.
The properties of the trend element are displayed in the Properties view. You can adapt the properties.
- . Configure the properties in Tick mark labels as follows:
Time stamps: Relative time stamps
Draw labels on two lines: Not selected
Omit irrelevant information in timestamps: Not selected
Internationalization (format strings), Date: Blank
Internationalization (format strings), Time:
HH:mm:ss:ms
The trend diagram is displayed as follows:
The time starts at 0 because the timestamps are displayed relatively. The time axis is labeled with one line and corresponds to the format string.