User-defined logical expression.

 Optional programmable logical expression in the C
 programming language. The expression is edited by means
 of the Attribute Editor at the object's Expression
 attribute. The expression, that does not include '=',
 is translated at the compilation.

 The Expression attribute is shown in the object.
 Up to 8 analog ( A1, ..., A8) and 8 digital ( d1, ...,
 d8) inputs.

 Digital inputs could be inverted either by means of the
 Attribute Editor or by the logical operator '!' in the
 Expression attribute.

 Note! If an arithmetic operator is followed by a graph
 name, e.g. A1, the operator and the graph name have to
 be separated by a space or a left parenthesis.
 If an input will be used as a constant quantity it is
 suitable to make the input invisible by marking Unused.
 We prefer to write the constant value direct into the
 Expression if it is not supposed to be changed. In this
 case no input is used. On the other hand, if we have to
 be able to adjust the constant in run time it is a good
 idea to use an Av or Dv object, as this will make it
 easier to get access from the object display. Unused
 inputs make compilation errors.

 1 Combinational circuit. In the following example '&&' means
   logical and, '||' means logical or and '!' means not.

   Expression: (d1 && d2 || !d3) && d4

   is equivalent with

 2 Maximum one of d1 - d5 is TRUE or d6

       Expression: ((d1 + d2 + d3 + d4 + d5) < 2) || d6

 3 Comparison.

       Expression: (A1 + 3.5 * A2) < A3

• AArithm
• CArithm

 Digital quantities included in the Expression

 Analog quantities included in the Expression attribute.

 The result of the latest Expression evaluation.

 Logical expression in the C programming language. The
 expression is edited by means of the Attribute Editor
 and can not be changed in the target environment.