Condition
A logical variable that has a label and a value of TRUE or FALSE. The input to a condition can be the result of either a measurement range or another logical operator, and the result of the condition can become the input to either a logical operator or a rule. See UPC Scenarios.
Control (direct)
For direct control, a structure is controlled by a regulator with no input from external sources: for example, a pump may be switched on or off to control the flow to a reservoir.
Control (indirect)
For indirect control, the output from sensors elsewhere in the system can be used to modify the operation of a regulator. For example, a sensor downstream from a valve may be set up to check pressure; the current value from the sensor can be used to decide whether the valve should be opened or closed.
Controller
A device to control a regulator in order to achieve a defined setpoint. See Controllers.
Initial state
The value of the setpoint for a regulator at the start of the simulation. See Regulators.
Logic operator
The combination of the output from two ranges or logic operators to give a TRUE or FALSE result. See UPC Scenarios.
Measurement range
See Range.
Output condition
The logical result of a measurement range or a logic operator, which may be either TRUE or FALSE. See UPC Scenarios.
Range
The definition of a range of acceptable values for measured variables, such as flow or depth. If the input value is between the minimum and maximum specified, the range returns a logical output of TRUE; otherwise, the result is FALSE. See UPC Scenarios.
Regulated variable
The variable controlled by a regulator. This can be the opening of a Valve, or the speed of a Pump. See Regulators.
Regulator
A control structure that physically constrains the flow. Regulators can be either continuous, where the variable can take any value within a permitted range (such as a valve), or discrete, where the variable can only be off or on (such as a pump). See Regulators.
Rule
A rule controls the status of a regulator. When the conditions on which a rule depend are TRUE the rule takes effect. See UPC Scenarios.
Scenario
A UPC scenario contains details of structures, sensors and rules that together determine flows throughout the network. See UPC Scenarios.
Sensor
Location of measurement of flow or pressure for use with a controller.
Setpoint
The target value of a regulated variable that a regulator is to achieve. A rule sets the setpoint. See Regulators.
Variable
An expression that combines values (from a range, table, logic operator, variable or constant value) to derive a new value. See UPC Scenarios.