A named set is a group of system or user-defined, mutually exclusive named states that are assigned a numeric value. The named state is a text string that represents a single numeric value from 0 to 255. The named set is a group of such numerically valued named states that forms a list from which the operator or configuration engineer selects an item.
Named sets are used in function block parameters where it is important to define a value or set of values from which only one value at a time is used (for example, motor states, valve states, module states, and so on) or any item where discrete values are used.
Use the named set to select the value in Control Studio (when configuring the control logic for the block or module) or in the operator environment (as part of the operator input).
The DeltaV software has default, preconfigured named sets that are accessed by selecting DeltaV_System/Setup in DeltaV Explorer. User-defined named sets are configured in DeltaV Explorer. Named set names are case sensitive. Names can include upper case and lower case letters, but all future references to the named set must be as originally defined (upper/lower case).
The Browse window for named sets displays only sets containing the same values and number of states that match the definition of the associated parameter. A user defined named set must contain the same values and number of states, but the named states (strings) can be different.
By selecting the named set mtr2-sp for the SP of the control block for the motor, you can customize the operator environment to allow the operator to choose the motor's state. This gives the operator the control of starting or stopping the motor when the need arises.
Selecting STOP for the SP sets the value to 0. Selecting START for the SP sets the value to 1. STOP and START are the only two values that are visible to the user and that the user can select for this named set.
The named set does not have to be visible to or selectable by the user. However, if you want the set to be selectable by the user, it must also be visible to the user. In addition, named set states have to be configured as user selectable for the state names to be available for use within the controller.
To configure named sets, start DeltaV Explorer and select Setup/Named Set. Right-click, and then select New Named Set from the context menu. Name the set (for example, FILL _LEVEL). Named sets are case sensitive. Right-click the new named set in the Contents window (right window pane in Explorer), and then click Properties. Set the properties and click OK. When configuring the control module for that tank and level indicator, use the named set FILL_LEVEL to indicate the current level of the tank.
CAUTION!