NumericPoints with “CV” attribute

PUP proxy points that are type Numeric Point (read-only) configured with an Attribute property of “CV” have a special behavior. Figure 20 shows an Add dialog in the Pup Point Manager configured to create a Numeric Point with the CV attribute.

Figure 20. Adding NumericPoint with CV Attribute

In this case, the special behavior is the addition of a command (action) to set an override value to the point. However, this requires some additional configuration to perform correctly. In particular, the “Prewrite Attribute” property of the proxy extension must be set to the appropriate value, as shown being done in Figure 21.

Figure 21. Prewrite Attribute value being selected

This property is invisible until an attribute value of “CV” is entered, whereupon it is listed in the property sheet of the proxy extension. The value of Prewrite Attribute defaults to “None”. If the value is changed to “Oi” or “Am”, then a dynamic action is added to the proxy point to allow setting of the CV value.

These are the basic rules to be able to use the set action:

The PUP proxy point Type must be Numeric Point (Numeric Writabledoes not work).
The “Attribute” property must be set to “CV”. This makes the “Prewrite Attribute property visible in the PupNumericProxyExt.
The “Prewrite Attribute” property must be set to “Oi” or “Am” depending on whether the OI attribute or the AM attribute must be written before the CV value can be written. This varies from channel-to-channel, and/or device-to-device.
If the “Prewrite Attribute” is “Oi” or “Am”, than the appropriate pair of actions is added to the proxy point, as follows:
- If the Prewrite Attribute is set to “Oi”, then the actions “Override” and “CancelOverride” are added to the proxy point, as shown in Figure 22.
  
  Figure 22. Override actions from “Oi” value for Prewrite Attribute
  - Invoking the “Override” action sets the “OI” attribute in the PUP controller to 1, and writes the user-entered value to the attribute “CV”.
  - Invoking the “CancelOverride” action resets the “OI” attribute in the PUP controller to 0.
- If the Prewrite Attribute is set to “Am”, then the actions “Manual” and “Auto” are added to the proxy point, as shown in Figure 23.
  
  Figure 23. Manual/auto actions from “Am” value for Prewrite Attribute
  - Invoking the “Manual” action sets the “AM” attribute in the PUP controller to 1, followed by a write of the user-entered value to the attribute “CV”.
  - Invoking the Auto action resets the “AM” attribute in the PUP controller to 0.