Many animations and other entities need to be connected to one or more expressions or values. 

Where the description of the field contain the Expression entry  in place of Item, you can enter the name of a single item or system variable, or constant values ​​(e.g., TRUE, 0, 1, -1, FALSE, etc..) and VBScript expressions (e.g.. SQR (ITEM_1) / ITEM_2 + 3.6 ).


Note: animation can show the result of an expression, but in this case cannot accept inputted data from XView.


Below some examples of valid expressions:


(ITEM_1 ITEM_2 +) ^ 1/3


ITEM_1/1000


Item_5 * (65-ITEM_1)


Item_3 = 1                (returns -1 if the comparison is true; 0 if false)


Important notes

The OR and AND operators are Bitwise operator, not Boolean operators.

The Digital item type  can take the values ​​0 (OFF) and 1 (ON), while the values ​​TRUE and FALSE, respectively, correspond to the numerical values ​​0 and -1.
In particular, any value other than 0 is considered True, while the value 0 is considered False. Conversely, an expression that evaluates to True (for example, a comparison) does not return 1 but -1 (the value of True in VB Script syntax).

The NOT operator makes a logical negation according to the VB Script logic
Therefore:


ITEM_1 OR ITEM_2

For Digital items, the expression returns 1 if at least one item has value 1, 0 otherwise, according to the truth table for the binary OR operation.
If instead one or more items are of Analog type and assume a value other than 0 or 1, the expression returns the bitwise OR between the values ​​(e.g. 1 = 6 OR 7, OR 7 1 = 7)

ITEM_1 AND ITEM_2

For Digital items, the expression returns 1 if both items are 1, 0 otherwise, according to the truth table for the AND binary.
If instead one or more items are of Analog and assume a value other than 0 or 1, the expression returns the bitwise AND of the values ​​(e.g. 1 AND 2 = 0, 1 AND 3 = 3)

TRUE

Returns -1

FALSE

Returns 0

ITEM_1 = 2

Returns -1 (not 1!) If ITEM_2 has a value of 2, 0 otherwise.

NOT (ITEM_1)

It does not return the inverse binary (0à1; 1à0) the value of the item, but it has instead:
NOT (0) = -1

NOT (-1) = 0

For analog data, the resulting value is given by the application of the truth table above exposed to each bit of the argument.


To obtain the inverse binary, so that the expression evaluates to 0 if the item is 1, and 1 if the item is 0, it is necessary to introduce an expression of the type:


ABS (NOT (CBool ​​(ITEM_1)) 


The final result of the expression must be compatible with the data type expected by the function controlled by the expression itself: the table below shows the results consistent with the main features:


If the Expression field refers to the Functionality:

The expression must return a final value of type:

Text (Text Animation)

Any

Thresholds for colors, text, images 

Numerical

Visibility

Boolean (TRUE or FALSE) or Numeric (= 0 or ≠ 0)

Enabling

Boolean (TRUE or FALSE) or Numeric (= 0 or ≠ 0)

Dynamic change of location or size (animations)

Whole number

Dynamic variation of the rotation angle (animations)

Numerical

Value and min / max range limits  (animations)

Numerical

Minimum value; maximum value (animations Slider and Spinner)

Numerical

Value (animation tool, Checkbox)

 

Numerical

Marked (Menu)

Boolean (TRUE or FALSE) or Numeric (= 0 or ≠ 0)

Expression (General Calculations)

Numeric item type for Digital and Analog, Text String, Number, Boolean, or for items of type Text

Expression (Actions on event)

Boolean (TRUE or FALSE) or Numeric (= 0 or ≠ 0)