Using the explicit solver, a user can control the behavior of elements based on the condition in some other element using control rules set based on the SWMM program. These control rules are based on the syntax rules presented below and in the Help (”Control Set Formats’) and are not used by the other solvers.

A user indicates that a control set is to be used in a give scenario by setting "Apply SWMM control set" to True in the Calculation options for that scenario, then picking the appropriate control set from the drop down list in "SWMM Control Set". The control set must already have been created.

It is best to only specify either a SWMM control set or on/off controls for a model but not both as the two types of controls can conflict.

This dialog box allows you to create, view, and manage SWMM controls. Access it by selecting Components > SWMM Extensions > Control Sets.

This dialog box contains a toolbar, a list pane on the left that displays all of the controls that have been defined in the current model, and a control editor pane on the right that allows you to enter and edit the currently highlighted SWMM control definition. The toolbar contains the following buttons:

The Control Editor Pane allows you to define SWMM controls. Each control rule is a series of statements of the form:

RULE ruleID IF condition_1 AND condition_2 OR condition_3 AND condition_4 Etc. THEN action_1 AND action_2 Etc. ELSE action_3 AND action_4 Etc. PRIORITY value

where keywords are shown in boldface and ruleID is an ID label assigned to the rule, condition_n is a Condition Clause, action_n is an Action Clause, and value is a priority value (e.g., a number from 1 to 5).

Only the RULE, IF and THEN portions of a rule are required; the other portions are optional.

Blank lines between clauses are permitted and any text to the right of a semicolon is considered a comment.

When mixing AND and OR clauses, the OR operator has higher precedence than AND, i.e.,

IF A or B and C

is equivalent to

IF (A or B) and C

If the interpretation was meant to be

IF A or (B and C)

then this can be expressed using two rules as in

IF A THEN …IF B and C THEN …

The PRIORITY value is used to determine which rule applies when two or more rules require that conflicting actions be taken on a link. A rule without a priority value always has a lower priority than one with a value. For two rules with the same priority value, the rule that appears first is given the higher priority.