Writable points have actions—by default, these appear in a right-click menu when you select a point in a Workbench view or in the Nav tree (Figure 93).
An action is a slot that defines a behavior. Some other control objects and extensions also have actions.
In the case of the 4 writable control points, default actions include the ability to:
-
Override the point at priority levels 8 (override) and 1 (emergency override), where control can be independently set or “auto’ed” at either level. A level 8 override can be for a defined (or custom) length duration, as specified in the action’s popup dialog. See About override actions.
-
Set the value of the point’s “Fallback” property. See About set (Fallback) action.
Often, you modify a writable point’s default actions—see Modifying default actions.
Whenever a writable point is controlled from an action issued at either override level, it has an “override” status. By default, override status color is magenta, as shown in Figure 93. For more point status details, see How status flags are set.
A manual (level 8) override action to a point (not “auto”) prompts for an override duration, see Figure 94.
Emergency overrides (level 1) do not have durations—these overrides are “permanent” (until auto’ed).
By default, a “Permanent” override is the first choice in the drop-down list—the override value will remain effective until the next time this action
is auto’ed. Other timed durations are available, including a “Custom” selection in which a user specifies a duration in hours, minutes, and seconds.
If needed, you can limit the maximum duration of manual override using facets—see Maximum override duration facet.
After clicking OK, the override action is issued to the point—if this is the highest effective priority level, the writable point operates under this control. If this is a timed override, the action is automatically auto’ed upon expiration of the override period.
Whenever a writable point has a “null” or “invalid” value at inputs In1—In16 (note this means that both override levels are currently “auto’ed”), the Out slot is set to the value of the Fallback property. For more details, see About the priority scheme.
By default, an operator-level user can change the Fallback property, using the “set” action. This produces a popup dialog that displays the current Fallback value (Figure 95).
From the set action prompt, a “Cancel” leaves the current Fallback property unchanged. Otherwise, the Fallback property is set to the value entered (or currently displayed value).
The set action prompt does not display (or accept) a “null” value for Fallback. However, a Fallback of null can be entered from the point’s property sheet.
A common application for this feature is with NumericWritables used as setpoints, particularly under a NiagaraNetwork. As Niagara proxy points are always read-only points (not writable types), yet inherit any actions of the source point, this feature provides user access to setpoints via px graphics without creating additional proxy points. In particular, this “set” action is designed to work well with “SetPoint” type widgets (found in the kitPx palette). For related details, see the NiagaraAX Graphics Guide section “About Widgets”.
Each of the four “constant” kitControl components also provides a “set” action that works in a similar manner, including with kitPx widgets. However, a constant object (NumericConst,
BooleanConst, etc.), has no priority inputs or Fallback property—the set action simply writes directly to the component’s
current Out slot. For details, see the “About Constant components” section in the kitControl Guide.
Unless all the “defaults” for actions of a writable point are acceptable (display names, all actions available, default user access), you may wish to modify action defaults. You can do this selectively from the slot sheet of the writable point. For general information, see About slots, and Using the slot sheet.
Or, using facets you can limit the duration of manual overrides—see Maximum override duration facet.
The following sections provide more details on slot sheet techniques:
-
Display names — Change how the point’s popup action menu lists available actions
-
Action access — Limit the actions that are made available, either by user level or for all users
As a “global” alternative to editing display names on slot sheets, you can edit the default values of lexicon keys, in this
case for the control module for action type slots. For details, see “Notes on English (en) lexicon usage” in the NiagaraAX Lexicon Guide.
You can also modify the display name of the same action in multiple points in a single operation, using the (default) “Batch Editor” view of the station’s ProgramService (Config > Services > ProgramService). This is one of many examples of using the Batch Editor, available in all NiagaraAX releases.Also, starting in AX-3.6, you can use the Batch Editor to modify a config flag of the same slot on multiple components in a single operation. For details, refer to the Batch Editor - Engineering Notes document.
By default, action display names are generic (“Emergency Inactive” and so on). You can change the display name for any action. From the slot sheet, click on an action’s Display Name for an editor (Figure 96). When you change a display name from defaults, it appears in listed in bold.
When a user invokes an action, the popup menu lists possible actions by more meaningful descriptors. For example, you could change the “set” action display name from “Set” to “Set Fallback.”
By default, for any writable point, all actions are available to any admin-level user, and all actions except emergency-level ones are available to an operator-level user. As needed, you can selectively “hide” actions (from any level user), or change default permissions for actions.
From a Px widget, you can also disable Px access to a bound writable point’s actions, by setting the “popupEnabled” binding
property of the widget to false. In this case, access to the point’s actions would still be available from the point’s property sheet or in the wire sheet,
unless otherwise changed from its slot sheet. For related Px details, see the NiagaraAX Graphics Guide section “Types of binding properties”.
From the slot sheet, do this by editing the action’s config flags (right-click the action and select , as shown in Figure 97).
In the Config Flags editor, you click to assign or remove config flags. As pertains to action slots, the following flags are most often changed:
-
Operator
If checked, only operator-level access is needed to invoke the action. If cleared, admin-level access is needed. For details on permission levels, see About permission levels.
-
Confirm Required
If checked, a second (confirmation) dialog appears after the action is invoked, before the action executes. An example confirmation dialog is shown in Figure 98. By default, this flag is cleared.
-
Hidden
If checked, the action does not appear (is hidden) from the action popup menu—for any user. You may wish to do this selectively for some actions, for example, the “set” action for Fallback access. (Note that a user with admin-level rights to the point may still access the point’s slot sheet.)
As previously noted, starting in AX-3.6, the Batch Editor lets you modify a slot’s config flag on multiple points in one operation. Refer to the Batch Editor - Engineering Notes document for details.