Mathematical expressions in eval tags and events

Mathematic expression determining the value of an object of Eval tag type may be, in dependence on the object configuration, evaluated either periodically or at the change of some operands (the parameter Evaluation method in the configuration of eval tags).

Mathematical expression used in the configuration of object of Event type is evaluated immediately as soon as the event evaluation reaches the line containing the given expression.

In both cases, the defined expression consists of operands and operators.

Each expression in D2000 System in addition to the values, specifies their time stamps "ValueTime".


The chapter Usage of brackets in expressions describes all possible types of brackets used in expressions and the chapter Conditional expression contains the rules for writing conditional expressions.

Admissible operands in expressions
Operators in expressions