Column Headings for other Types of Filtered Value Map

Filtered Value Maps other than Filtered BIT Value Maps and Filtered String Value Maps contain the same column headings as Value Maps (see Column Headings for other Types of Value Map), plus these additional column headings:

• Event Change Detection—Filtered Value Maps can store events for the slave device. Use this column to specify which type(s) of event a Filtered Value Map is to store for each value. Choose from:
  • Filtered Chronological Update—The default option. The Filtered Value Map generates and stores events whenever a source value changes, provided that:
    • The source value either exceeds any of the thresholds specified in the Limit fields, or changes by the Sig Change Deadband or more.

    and:

    • The time stamp indicates that the value change is newer than the last update.
  • Generated on Update—The Filtered Value Map generates and stores events whenever a source value exceeds any thresholds specified in the Limit fields, or changes by the Sig Change Deadband or more (see below). This option will also generate events if the time stamp of the update is older than the previous update.

    Select either this option, or the Filtered Chronological Update option, if the data sources do not have historic data, or you do not want to use the source’s historic data. The Filtered Value Map will generate events for the source value changes.

  • Reason for Logging—The Filtered Value Map stores those source events that fulfill the criteria specified in the Reason Mask column (see below), rather than events generated by exceeding any thresholds specified in the Limit fields.

    Select this option if the data sources do have historic data, and Geo SCADA Expert is to use that historic data for the events.

The four deadband limits are used within each Filtered Value Map to indicate whether a change in value has caused a change in state—if so, this is stored as an alarm at the Value Map, and is reported to the Master as part of the ‘reasons for change’ for that value. You can specify four deadband limits:

• Low Low Limit—Specify the limit below which the value is deemed to be in the Low Low state. If the value changes and crosses this or any of the other limit deadbands (see below), the occurrence is raised as an alarm, and the alarm is reported to the Master as part of the ‘reasons for change’ for that value.
• Low Limit—Specify the limit below which the value is deemed to be in the Low state.
• High Limit—Specify the limit above which the value is deemed to be in the High state.
• High High Limit—Specify the limit above which the value is deemed to be in the High High state.

These column headings are also displayed for each Filtered Value Map:

• Sig Change Deadband—If a value changes by this amount or more, it is deemed to have changed significantly. If the value changes significantly, but does not cross one of the four limit deadband (for example, High), the occurrence is logged as an event. This is reported to the Master as part of the ‘reasons for change’ when the Master requests data from the Slave.
• Reason Mask—Only used when the Event Change Detection (see above) is set to Reason for Logging. A data source might store values historically for one of many reasons. Use the Reason Mask to specify which of those values a Filtered Value Map is to retrieve and store for an entry.The Reason Mask is a comma-separated list. By default, it lists each of the reason(s) for which the source might have stored a value historically. Use the list to specify which of those logged values the Filtered Value Map is to retrieve and store historically. The list varies, depending on the type of Filtered Value Map—delete any reasons that are not required.

  The types of event that a Filtered Value Map might store include:

  • Value Change—The Filtered Value Map stores the event that the source logs whenever a change in value occurs.
  • State Change—The Filtered Value Map stores the event that the source logs whenever a change of state occurs.
  • Report—The Filtered Value Map stores the event that the source logs on timed report (background logging that occurs at regular intervals).
  • End of Period—The Filtered Value Map stores the event that the source logs as an End of Period value.
  • End of Period Reset—The Filtered Value Map stores the event that the source logs due to an End of Period reset.
  • Override—The Filtered Value Map stores the event that the source logs whenever an outstation override occurs.
  • Release—The Filtered Value Map stores the event that the source logs whenever an outstation override is released.

  Example:

  For a Filtered Value Map to store those events that a source generates whenever a value changes state, is overridden, or has an override removed, set the Event Change Detection to Reason for Logging and specify the following Reason Mask:

  State Change, Override, Release

  In addition to the above, add CDR to the comma-separated list if you want the Filtered Value Map to store current values historically.

• Class—The type of data that the slave reports to its master has to be assigned a class. The class is used at the master to assess which type of data to retrieve from the slave. For example, on DNP3, Class 0 specifies static data (present values and states).

  Each Class row within a Filtered Value map is automatically assigned as Class 0 when a variable, point, or other value is allocated to that row. Alter from the default if a different class is required.