You can display alarm limits for a value displayed in a trend chart in WebStation.
The value displayed in the trend log must be monitored by an alarm. The alarm must have the limit configured.
You cannot edit, or change, the displayed alarm in the properties for the trend chart or trend log. However, if you edit the limits in the alarm, the new limits are displayed in the chart.
If more than one alarm is monitoring the value that is displayed in the trend chart, the limits for all alarms are displayed. If many values are displayed in the chart and every value is monitored by an alarm with limits, all alarm limits are displayed in the trend chart.