SWMM - Control Rules - Named Variables

Named variables are nicknames used to represent the trio of <object type | object name | object attribute> (or a doublet for simulation times) that appear in condition clauses of control rules. They allow condition clauses to be written as:

 variable relation  value 

Or:

 variable relation  variable

Where the variable is defined on a separate line before its first use in a rule using the format:

 VARIABLE  name = object id attribute

Here is an example of using this feature:

VARIABLE  Dabc  =  NODE  abc  DEPTH
VARIABLE  Defg  =  NODE  efg  DEPTH
VARIABLE  P45   =  PUMP  45   STATUS

RULE 1
IF    Dabc > Defg
AND   P45 = OFF
THEN  PUMP 45 STATUS = ON

RULE 2
IF   Dabc < 1
THEN PUMP 45 STATUS = OFF

Note: A variable cannot have the same name as an object attribute.

Named variables are required when using arithmetic expressions in rule condition clauses.

On SOLIDOS (command SWMMCONTROLS) , the variables are created in the table below:

See also: SWMM Rules Controls