Analog input.

 Configures an analog input signal in the Plant
 Configuration.

 Put the object below a $PlantHier object in the
 development environment in such a way that it belongs
 to the same target node as its associated channel
 object.

 Optional text, e.g. name of the signal or what it
 represents.

 Name of the associated channel object.

 Index in the AIValue array of the Ai_Value_Base objects
 that are used for base frequency and partial frequency
 samples. Initiated at boot time by rs_init.

 Pointer to the engineering value, named ActualValue.

 InitialValue specifies starting value of the signal at
 so called 'cold start'. Which value that is used as
 starting value at warm restart ( = change of PLC
 program ) depends on whether the signal is new or not.
 If the signal has exist in the last program its last
 value will be used as starting value, otherwise InitialValue

 Engineering unit of ActualValue.

 Number of decimals at presentation of ActualValue.

 The lower respectively upper limits in the bar graph at
 presentation of ActualValue in the object display.

 Signal value.

 Raw value, i.e. normally the bit pattern of
 A/D-converter.

 Xtt method configuration.
 Specification of the available methods for the object.
 If Flags.IsConfigured is set, the methods can be specified in
 the development environment. Otherwise they will be calculated
 in runtime.

 A XttGraph object that will open a graph that contains data for
 this object. This graph can be opened from the popup menu for
 this object.

 A DsTrend or PlotGroup object that contains a trend for this object.
 The trend can be opened from the popup menu for this object.

 A help topic in the xtt help file that contains help for this hierarchy.
 The help can be displayed from the popup menu for this object.

 An URL to the data sheet for the equipment in this hierarchy.
 The data sheet can be displayed from the popup menu for this object.

 An URL to the circuit diagram for the equipment in this hierarchy.
 The circuit diagram can be displayed from the popup menu for this object.

 If the attribute is empty, the CircuitDiagram method will look at the
 closest ancestor that has supplied a value in CircuitDiagram and use this
 URL instead. If this behavior is unwanted, put the string 'Disabled' in the
 attribute. This will disable the CircuitDiagram method for this object, and
 for any child with empty CircuitDiagram attribute.

 A photograph of the plant.
 A URL to a photo of the equipment.
 The photo can be displayed from the popup menu for this object.

 A note of the current status of the object.
 Notes are used to exchange information between operators. It is handled
 by the Note method.

 The internal filter function concerns only local
 Ai-signals.
 Specifies the selected filter. The possible types of
 filters are:

 0 -- No filtering.

 1 -- Exponential filter.
    The filtering is done on the engineering value,
    ActualValue, before storage in rtdb according:

    ActualValue(t) = ActualValue(t-1) + a * (InValue - ActualValue(t-1))

    where
    - ActualValue(t-1) is the engineering value stored at the
      former sample
    - nValue(t) the current engineering value before filtering.
    - a = ScanInterval * ScanTime / FilterAttribute[0]
      and 0 < a < 1.0

    If a >= 0 no filtering is done. The less a the harder
    filtering.

    The product ScanInterval * ScanTime specifies the updating
    period of the signal

 Defines filter constants in selected function, see
 FilterType. The constants are specified in seconds.
 Only if FilterType = 1 and FilterAttribute[0] >
 ScanInterval * CycleTimeBus (= the updating period of
 the signal) is filtering done.