General

The
General
 group contains the following point attributes:
Use this attribute
To
Name
Name the point, following these rules:
  • The name must be unique.
  • The first character must be alphanumeric or the percent sign (%).
  • The name must not contain:
    • Control characters (such as line feeds or tabs).
    • The following characters: * ' ? ; : { } [ ] | \ / ( ) ` "
Descriptor
Type a basic description of the point. The description will be displayed in client applications and user reports.
Extended Description
Specify a relevant expression or a tag name. For details, see Configure Trigger Input and Output points.
Use this attribute only with trigger input and output points.
Instrument Tag
Provide a full path to the controller and the tag from which the data is coming. If you replace the controller with a different one that measures the same process value, it is usually best to continue using the same point. Edit the point as required so that it will collect the new data.
Use the following format of the path:
[<controllerprojectname>_1_<controllerslotnumber>][<controllertagname>]
When a source tag receives events from the controller, the tag that you set in this attribute reads (or writes back) events from the controller.
Note:
  • It is recommended that you do not change the tag name in the attribute, since it may make the tag invalid, and make it stop collecting data.
  • If the full path points to a controller in a remote chassis, and the tag from which data is coming is a high-speed or an output tag, the configuration will not be supported.
Source Tag
Type the trigger tag name. If you type a tag name, the source tag referenced must not be high-speed or have a scan rate of faster than 1 second. Otherwise, the module will generate an error and you will not be able to save the point.
Use this attribute only with the Trigger Input or Output tags.
Type
Set the data type of the point values. When you change the point type, the archive subsystem closes the current archive record, and starts a new one with the new type information in the header. For points collected automatically, use the point type that most closely matches the point type in the source system.
Choose from the following:
  • Int16
    For points whose values are 16-bit integers.
  • Int32
    For points whose values are 32-bit integers.
  • Float16
    For points whose values are 16-bit floating point values.
  • Float32
    For points whose values are 32-bit floating point values.
  • Float64
    For points whose values are 64-bit floating point values.
  • String
    Used to store string data up to 1000 characters.
    Note:
     Strings are not supported for high-speed data collection.
  • Digital
    For points whose values can only be one of several discrete states, such as ON/OFF. You can define digital set contents.
  • Timestamp
    For points whose values are timestamps.
Digital Set
Select the type of digital set for the point.
Choose from the following:
  • SYSTEM
  • BatchAct
  • Phases
  • Modes
  • RABoolean
Use the System Management Tools of FactoryTalk Historian SE to create additional digital sets. For more information, refer to the
PI Data Archive 2015 R2 Introduction to System Management Guide.pdf
.
This attribute only appears if the point is of type
digital
.
Scan Type
Determine the scan type for the point.
Choose from the following:
  • Polled
  • Advised
  • Trigger Input
  • Output
  • High-speed
Note:
 For details, see Configure scan types.
Scan On
Identify active tags. The active tags are updated. If you want a point to be the active point, set this attribute to
On
 and the point source to
FHTME
.
Typical Value
Type a reasonable value for a point.
For a numeric tag, it must be greater than or equal to the value of the
Zero
 attribute, and lower than or equal to the sum of the
Zero
 and
Span
 attribute values.
The typical value range is between 0 and 100.
The typical value range for the points of type
Digital
 is between 0 and 1.
Point Source
Identify the interface to which the point belongs.
When you configure an interface, you specify a point source for the interface. All the points that belong to the interface must use that point source code as the value for the
Point Source
 attribute.
The default point source is
FTME
. Other options include:
  • T, for the Totalizer utility subsystem in PI.
  • C, for the Performance Equation tags.
Scan Rate
Set the time in seconds, which tells FactoryTalk Historian ME how often to collect the data.
For the Trigger Input and Output scan types, it is recommended that the scan rate is defined as two seconds or longer.
For details, see Use scan classes.
Span Value
Set the difference between the top and the bottom of the range.
This attribute is required for all numeric data type points.
For
Float16
point types, the
Span
value is used with the
Zero
value for scaling values in the archive. The
Span
property must be a positive value. If the value for a
Float16
 point type is greater than the top of the range, it is recorded in the archive as
Over Range
.
For other point types, the
Zero
 and
Span
 values do not affect the values recorded in the archive. The
Span
property is also used when defining a FactoryTalk Historian ProcessBook trend with a vertical scale of database. This attribute is not used for non-numeric points.
Zero Value
Type the lowest value possible.
This attribute is required for all numeric data type points. It does not have to be the same as the instrument zero, but that is usually a logical choice.
The zero value range is between 0 and 100.
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