Logic Equation - Metasys - LIT-12011942 - Software Application - ODS Server - 10.1

Metasys Open Data Server Help

Product name
ODS Server
Document type
User Guide
Document number
Revision date

Valid characters in the Logic Equation string are:

*AND operator

+OR operator

(Open parenthesis (for grouping)

)Closed parenthesis (for grouping)

numbersMaster condition numbers

spacesSpaces are allowed for readability

Equation Syntax

  • Open and close parenthesis must match.

  • Empty parenthesis are not allowed ().

  • The equation must be at least 3 characters in length, not including spaces.

  • The numbers must not exceed the master condition numbers.

  • There is no implied precedence for the operators (*,+).

  • Any combination of different operators must be grouped with parenthesis to determine precedence.

  • Operators of the same type do not require the use of parenthesis.

  • A grouping may contain only one operator type.

  • Numbers or groupings must be separated by an operator (*,+).

  • Groups can be nested.

Table 1. Examples
Incorrect Correct
1+2+3*4 1+2+(3*4) or (1+2+3)*4
1*2+3*4 (1*2)+(3*4) or 1*(2+3)*4
1*2*3+4 1*((2*3)+4) or (1*2)*(3+4) or (1*2*3)+4
(1+2)*(3+4)+(6*7) ((1+2)*(3+4))+(6*7) or (1+2)*((3+4)+(6*7))
(3*4)(1*2) (3*4)*(1*2)
(3*+1) (3*1)
(3* (3*1)

Sample Logic Equation


Where the equation says that master condition ((1 OR 2) AND (3 OR 4)) OR (6 AND 7) results in a TRUE (Action Tbl 1) execution.

Objects are given numbers in the left column that correspond to the order you add them to the Interlock Definition list (the first added is 1, the second added is 2, and so on). Use these numbers to represent the corresponding objects in the Logic Equation.