It is only possible to consistently reduce the number of parameters and to simplify the parameterization via the concept of derivation by making a comprehensive formula apparatus available. The formula apparatus makes it possible not only to query specific configurations using simple if-then-else constructs, but also to use basic mathematical operations to calculate device tags or IO addresses.
Formulas are used in a manner similar to how they are used in MS Excel. For example, a formula always begins with an equals sign =. Parameters are addressed by using the full name of the parameter preceded by a dollar sign $.
Example:
An equation for the sum of parameters A and B would appear as follows:
=$A+$B
In addition to simple calculations, the formula apparatus can also be used to ‘navigate’ through the entire structure of a machine or plant. This means that every parameter, regardless of which component it belongs to, can be included in a calculation. There are various formula constructs for this type of navigation; the most important ones are mentioned here. Should a user wish to address a parameter from a superordinate level within a machine or plant, this can be accomplished using the mc construct.
Example:
If a user wishes to calculate the sum of parameters A and B, where parameter B belongs to a superordinate element, the equation would appear as follows:
=$A+mc.$B
A detailed breakdown of all available formulas may be found in the Formulas section.