Tag Editor

Data

Configures the generic tag parameters as well as the data retrieval/generation method. The following parameters are available:

Metadata

• Tag name
  Name of the tag that will be shown in the Portal and included into the full tag path as the suffix for where tag paths are of use (e.g., in Export and Import).
• Custom name
  An alternative name that can be displayed instead of, or together with, the standard tag name in the HMI.
• Description
  Localizable field with text to be displayed in the HMI for added convenience.

Name and custom name can also be set for devices and folders as articulated in Tags; these names behave identically to tag names as described above.

Type

Selects a subconfiguration for the HMI view of the tag, e.g., in Tag Lookup:

• Simple
  Basic variant with no additional display.
• Regulator link
  Creates a shortcut to the page selected under Editor page; the shortcut becomes visible when viewing the tag in the Tag Lookup interface.
• Time channel
  Deprecated.

Data type

Available for the following tags: Modbus, BACnet, TwinCAT ADS, MQTT, and Virtual Tag.

• integers (whole numbers), which can be encoded as 16-, 32-, or 64-bit data; listed as intX, where X stands for the wordWord
  A bit sequence of fixed length, referred as word size or bitness, that represents a complete minimum unit of handleable data. size.
• unsigned integers (positive-only whole numbers), which can be encoded as 16- or 32-bit data; listed as uintX
• boolean values (true or false)
• floats (32-bit numbers with support for decimal point)
• doubles (64-bit numbers with support for decimal point)

All these data types are supported as scalars (singular values) and arrays (ordered sequences of values); the latter are marked with brackets, [], in the dropdown menu. Certain device-specific parameters may limit the availability of data types, see sub-articles under Device-Based Tags for details. As a rule of thumb, array output for device tags is available only when the tag is configured to read a set of sequential data points, regardless of the data type. Such configurations also typically have a number of elements greater than 1.

Two device-based tags, OPC-UA and M-Bus, do not have this parameter due to protocol specifics; this also affects how the External data type is configured.

Request interval

Device-based tags only.

Determines how frequently the tag will be polling the device. The default interval is 0 minutes 5 seconds 0 milliseconds. Note that this option is not available if the tag is configured to receive notifications from the device on value updates; this feature is supported for BACnet and TwinCAT ADS.

Number of elements

Device-based tags only.

A positive integer — the number of consecutive values read/written by the tag. Only active if the selected data type is an array; otherwise, defaults and locks to 1.

Writable

Check to allow tag values to be overwritten manually from the HMI. The following terminology applies:

• A tag is said to be writable or made writable if its Writable parameter is checked. Such tags can be overwritten by the user when viewing a page in HMI or inspecting that particular tag via Tag Lookup.
• A tag is said to support writability if its configuration allows for two-way, read-write communication of data. Parameters that determine writability support in device-based tags include, for example, Modbus function or BACnet object type. Sub-articles under Device-Based Tags contain more information on configuration-specific writability.

Therefore, checking Writable makes the tag user-writable. Several important considerations apply:

• A tag cannot be made writable if it does not support writability. In such cases, the checkbox is either grayed out or not shown at all.
• A tag that supports writability does not have to be made writable in order to be affected by other tags:
  • In a generator tag, the output tag (usually a setpoint) must support writability but does not have to be made writable.
  • A Vector Element can be made writable, in which case it will accept user input in the HMI and overwrite the applicable index of the source tag as long as latter supports writability, regardless of whether it has been made writable.

General

Not available for Regulator tags.

External data type

Determines how the tag’s value should be rendered in Tag View and in the HMI. The following options are available:

• Integer
  Rounds the value to the nearest integer; can only show 0 or 1 if the data type is set to boolean.
• Float
  Presents the value as is; can only show 0 or 1 if the data type is set to boolean.
• Boolean
  Shows 1 if the value is true or a non-zero numerical, 0 otherwise; limits the options for, or completely disables several parameters covered further in this article.

External data type (EDT) selector respects the scalar-vs-array constraint of the data type. Thus, if the latter is set to be a scalar or an array, the EDT selector will only show scalars or arrays, respectively. Two exceptions exist: OPC-UA and M-Bus; since data type is not selectable on these device-based tags, EDT selection is unconstrained. Accidental mismatch is handled as follows:

• A scalar EDT will return index 0 value of the fed data array;
• An array EDT will return a single-value array containing the fed scalar.

Converter type

Selects the data transformation method. The following options are available:

• No data transformation
  Passes the output value through as is.

• Linear numeric transformation
  Transforms the output value by applying a factor obtained by scaling the range specified under Channel data properties to the range specified under External data properties, see example below:
  +Example 1

  Parameters		Effect
  Channel data properties:		Original value:	Transformation result:
  Minimal value: 0 (default)	Maximal value: 65535 (default)	24322	37.11233
  External data properties		Explanation: with a range [0; 65535] being scaled to fit [0; 100], linear transformation applies a scaling factor equal to 1/655.35.
  Minimal value: 0 (default)	Maximal value: 100 (default)

  Certain limitations apply to external data types Integer and Float: the latter may contain up to 7 digits, including those after the decimal point, whereas the former may not have a decimal point at all. As linear transformation is likely to produce a non-integer with a long decimal part, rounding will be applied as necessitated by the selected External data type.

  Linear transformation is not available if the selected external data type is Boolean.

• Multiply numeric transformation
  Multiplies the output value by the value specified under Factor; not available if the selected external data type is Boolean. Fractional factor values are supported.

  +Example 2

  Original value	Factor	Transformation result
  280	0.1	28

  Table above shows transformation for a sensor that scales its output at 10:1; see sensor example.
• Bit transformation
  Retrieves the bit with the specified Index from the binary representation of the output value. Bit indexation starts with 0. Index value must be an integer within the range [0; 31].
  +Example 3

  The number 10245 converts into binary code as 0010100000000101; thus, index 2 will return 1 or true since the bit with this index is a 1.

Do not require a comment on value change

Check to allow users to manually overwrite the tag’s value from the HMI interface without commenting.

Limits

Specifies criteria for value acceptability. The following options are available for the Limit type:

• None
  Sets limits automatically based on the tag’s possible range of values.
• Range
  Defines a range between the values in the Minimum and Maximum fields.

• Set
  Defines a fixed set of values that users are allowed to write to the tag; enter values in any order and separate with commas.

  When using a Range or Set limit, receiving a non-compliantNot allowed by the provided limit configuration value from the device will cause the nearest possible compliant value to be displayed and logged instead. Attempts to manually write a non-compliant value in HMI will return an error specifying the allowed range or set.

• Dynamic range
  Suppresses the display and logging of outliersOutlier
  A data point that significantly deviates from the mathematical expectation for the given distribution. if observed within a limited timeframe:
  • Cutoff Time Unit
    Specifies the unit to define suppression duration in.
  • Cutoff Time
    Specifies the suppression duration in the earlier selected units.
  • Top Cutoff
    Specifies the positive deltaIn this context, the difference between the updated value and its predecessor, exceeding which will initiate suppression.
  • Bottom Cutoff
    Specifies the negative delta, exceeding which will initiate suppression. Both cutoff values should be non-negative.

  Positive and negative deltas effectively define the non-compliant data points, or outliers. Table below shows the default values, followed by an explanation.

  Cutoff Time Unit	Cutoff Time	Top Cutoff	Bottom Cutoff
  Seconds	20	100000	0

  With this default configuration, dynamic range limit will follow the algorithm:

  1. Test each newly updated value $X_1$ against the preceding value $X_0$ for the requirement: $X_1 - X_0 < 100000 \vee X_1 - X_0 > 0 $; should $X_1$ fail the test, consider it an outlier and proceed to the next step.
  2. Initiate a countdown for the specified duration (in this case, 20 seconds) and continue to test the subsequent values $X_3,\space X_4…X_n$ against $X_0$ without logging them.
  3. If a newly updated value passes the test before the countdown expires, log it and erase the previously observed outliers.
  4. If the countdown expires before observing a compliant value, log all the previously observed outliers and reset the countdown.

  Non-compliant values will not be displayed unless the algorithm reaches Step 4 above.

  Figure below shows data logged with (green) and without (red) dynamic range limiting.

  

  Fig. 1. Effect of dynamic range limiting.

Limits cannot be configured if the external data type is set to Boolean.

String formatting

Controls how the tag’s value is presented in the HMI as well as in Tag View. Three parameters are available:

• Format string
  Determines the length of the decimal part for floats; the following characters are accepted: 0-9, #, .. The syntax is as follows:
  • The number of characters after the decimal point determines the length of the decimal part.
  • Use of the hash character (#) results in omitting the decimal part if the output is an integer.
  • Use of numbers results in preserving the decimal part even if the output is an integer, in which case the decimal part is shown to be zero.
  • At least one character should precede the decimal point; however, the number of characters before the decimal point does not affect string formatting.
  +Example 4. String formatting for an integer (100)

  Format string	Value	Displayed value
  0.00	100	100.00
  #.##	100	100

• Engineering unit
  Selects a unit to be appended to the value in the displayed string; alternatively, any string can be entered in the field if the desired unit is not on the list.

• Add unit
  Check to append the selected or entered engineering unit to the tag's value as displayed in the HMI or in Tag View. The selected engineering unit also affects graph generation under Reports.

String formatting cannot be configured if the external data type is set to Boolean.

Process always

See Virtual Tag.

History

Not available for Regulator tags.

Configures whether and how the values of the tag are logged, making a record referred to as the tag’s history.

General history parameters

• Store history
  Check to enable tag data logging. Default value varies by tag type.
• Use project history preferences
  Check to use project-wide history settings as configured under Preferences » History. Requires history storage to be active. Enabled by default.

Disabling history storage does not delete the existing data records. For history deletion, see Cleanup.

History aggregation

Requires history storage to be enabled without using project history preferences. Not available if the Data type is set to boolean

If Aggregate the tag values before storing is checked, data will be stored in an aggregated formData aggregation
Condensed representation of data produced by splitting the data into subsets and substituting each with a single representative value. determined by the following parameters:

• Request interval
  Length of the sampling period. Aggregation merges data points collected over a single sampling period.

• Function
  Selects the method by which data is aggregated. The following methods are available:

  • Average
    Returns the arithmetic meanTotal value of the aggregated data points divided by their number.
  • Median
    Returns the medianA value such that 50% of the aggregated data points have a lower value, and the remaining 50% have a higher value.
  • Percentile X
    Returns the X^th percentileA value such that X% of all data points in the aggregation sample have a lower value, and the remaining points have a higher value. of the aggregation sampleData points subject to aggregation, collectively..

    A percentile value always corresponds to a data point. Percentile 50 is equal to the median if the aggregation sample has an odd number of points. Otherwise:

    • the median is calculated as the arithmetic mean of two adjacent data points: the highest value in the lower half of the sample, and the lowest value of the upper half;
    • the 50^th percentile is the highest value in the lower half of the sample.

  • Maximum, Minimum
    Returns the highest or the lowest value recorded during the sampling period.
  • First, Last
    Returns the first or the last value recorded during the sampling period, chronologically.

Aggregation method and sampling period cannot be configured unless aggregation is enabled.

Exclude duplicate values: Deadband is a non-negative numeric value that constitutes the minimum difference between two consecutively logged tag values; value updates are not stored in the history if the difference is smaller than the deadband.

Switch tags

Check This tag depends on switch tags to create a logging suppressionLogging suppression
Conditional deliberate omission of tag values from the recorded history. rule:

• Switch tags
  Opens a tag selector to add one or more tags whose change of value will be monitored; only tags with a scalar boolean output can be selected.
• Invalid period before switching, Invalid period after switching
  Logging suppression period before and after an observed change of value in any of the monitored switch tags.

Enabled accumulate value

Not to be confused with value accumulation.

If checked, requires each new value to exceed the preceding value and will not store it in tag history otherwise.

Chart settings

If Interpolate points is checked, values between data points will be generated automatically to fit the distribution should the graph viewer in the HMI be zoomed in to an extent that requires a higher data resolution than the history sampling configuration allows; this produces a smoother curve but might introduce an unnecessary distortion.

Cleanup

• Enable history cleanup
  Check to enable automatic erasure of tag value entries from the logs stored locally on the Edge server; only affects local HMI.
• Delete history older than:
  Sets the time coverage of preservable log data in days preceding the latest value update.
  

• Also delete from cloud
  By default, history cleanup only affects the data viewable when using the HMI locally; accessing it on the web shows full history. Check this box to apply history cleanup to both local and cloud-based storage.