The Height property defines the size of the text in the text box. Typically, you would set the size of the font on the Text Properties window and would not animate this property, but you can animate it if required.
You can animate the Height so that the text is fixed at a specific size or you can animate it so that the size changes according to the value or state of an item in the database. The result of the expression has to define a number which is the height of the text (measured in points).
For example, you could use the following expression to change the size of text according to the state of a point:
LOOKUP( "<DigitalPoint 2>.AlarmState" + 1, 10, 10, 15, 20, 8)
Where <DigitalPoint 2> is the location and name of the 2 bit digital point (do not enter the angle brackets < >), the AlarmState is the point property that animates the Height property of the text box and the numerical values are:
- +1 is needed as LOOKUP is 1 based (starts from 1) whereas the point's alarm states are 0 based (start from 0).
- The first 10 is the size in points of the Height that is applied when the point has an alarm state of 0 (no alarms raised).
- The second 10 is the size in points of the Height that is applied when the point has an alarm state of 1 (alarms disabled).
- The 15 is the size in points of the Height that is applied when the point has an alarm state of 2 (acknowledged uncleared alarm).
- The 20 is the size in points of the Height that is applied when the point has an alarm state of 3 (unacknowledged cleared alarm).
- The 25 is the size in points of the Height that is applied when the point has an alarm state of 4 (unacknowledged uncleared alarm).
So for this example, the text would be 10 pt when the digital point had a normal alarm state or had its alarms disabled. When the point has an acknowledged uncleared alarm, the text is in 15 pt, if there is an unacknowledged cleared alarm the text is in 20 pt, and if there is an unacknowledged uncleared alarm the text is in 25 pt. This type of animation could be useful when you need to attract an operator's attention to an alarm and do not want to use changing or flashing colors to indicate an alarm has been raised.