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Editing of all objects in the process D2000 CNF is being performed in the configuration dialog box, a specific part of which is common for all editable objects and another part depends on the type of edited object.
Configuration The configuration dialog box of eval tags consists of several parts (tabs) that contain similar parameters.
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A text string describing the eval tag. Maximum: 128 characters.
Possibility to use the Dictionary (to open press CTRL+L).
Status Text
Defines a status text for the eval tag. Status The status text allows to redefine redefining values' identifications of the eval tag.
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Technical units of the eval tag. Maximum: 12 characters. Possibility to use the Dictionary (to open press CTRL+L).
Limits
Technological limits may be defined for eval tags of the Ce - integer, Ae - analog and TmR - time interval type. There are four limits: VHL, HL, LL and VLL. Limit The limit may be specified either directly - by entering a value into the input field, or its value may be defined by a system object (dynamic limit) - the button placed right from the input field.
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If the option is checked, it will remove invalid values when evaluating one of the defined process alarmalarms.
Example: value change from S1 to S2 is executed as follows: S1 --> invalid --> S2.
If the parameter is checked, the alarm evaluation will be: S1--> S2.
If the parameter is not checked, the alarm evaluation will be: S1 --> invalid --> S2.
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- Alarm - the column contains all possible causes to raise process alarm for the object of Eval tag type.
- State - the radio buttons allows to select allow selecting just one of the State, Transition or None options. Enabled State option means, that process alarm starts when the value of the I/O tag is, at least within the period defined by the Timeout parameter, in the particular state (the name of a particular state is placed in the particular row, in the Alarm column - pa_ValueStateName).
- Transition - checked Transition option means, that the process alarm starts when the I/O tag value will pass to a particular state (the name of a particular state is placed in the particular row, in Alarm column - pa_ValueStateName).
- None - if checked, process alarm is not evaluated.
- ACK - checked ACK option means, that the process alarm must be acknowledged by the operator in the process D2000 HI. "Transition" process alarm must be always acknowledged.
- Critical - flag of critical process alarm.
- Monitor - the option will write a particular change of a an I/O tag value state into the log database as a spontaneous value change.
- Display mask - selection of a display mask, that will be used in process D2000 HI (the Alarm list window - the Event description column) after changing the status of one of the defined process alarms into a particular state.
Raise SIGNAL
Raise signal parameter contains three checkboxes with the following function:
- the first checkbox - is placed below the State and Transition columns. Enabling the option, the system generates the signal, if any of configured process alarms occursoccur.
- the second checkbox - is placed below the Critical column. Enabling the option, the system generates the signal, if any of configured critical process alarms occursoccur.
- the third checkbox - is placed below the Monitor column. If checked, the system will generate the signal, if any of logged changes of defined process alarms is are written into the log database.
Generating the signal means, that the system tag Signal_Trigger is set to a TRUE value.
| Kotva | ||||
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The arithmetical expression that determines the eval tag value. The expression may contain the contain extended syntax, may could be written in several lines, and may contain a comment. Comment The comment begins with the character ';' and finish finishes at the line end. For example:
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Note: Typing the character '^' after the name of an object of the Structured variable shows the list of all structure columns.
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If checked, all invalid values of the objects defined in the expression will be replaced with the value of 0. The feature can be used to prevent the expression from getting invalid valuevalues.
There are converted just the values of input objects, invalid values of intermediate data are not converted. Values of inputs objects are converted as follows:
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Buttons to select an object of the D2000 system. Selected The selected object is inserted into the expression on the current cursor position.
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Buttons to select a constant. Clicking it , opens opens the dialog box containing the list of predefined constantconstants. Selected The selected constant is inserted into the expression in the current cursor position.
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Buttons to select a function. Clicking it , opens the List of the functions dialog box. Selected The selected function is to be inserted into the expression at the current cursor position.
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Buttons to select an attribute. Clicking it , opens the dialog box containing the list of attributes. Selected The selected attribute is inserted into the expression at the current cursor position.
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Start value is saved in a text form. During the system start, the Server assigns values to individual objects according to the start value definition. In case of the successful conversion of a start value (text) to the required type, a value of the eval tag will be valid. If the conversion is not successful, then this value will be invalid. It is possible to save a start value that cannot be converted to the required type. The button Start value checkout (
) checks the start value and, in case of unsuccessful conversion, reports it.
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If no target column is defined, the value of the expression (the input field Expression) will become the value of an eval tag. If it is defined, it must contain the reference to a column of an object of Structured variable type in form: ObjectName[0]^ColumnName. This notation defines a structured variable column, which will contain the results of the expression evaluated.
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Note:
If a constant expression of value 1 is defined, the process D2000 Calc (admistrator administrator of objects of Eval tag) type ) ensures that all fields of a defined column will have the same value of 1.
If there is an expression Sec+1, the process D2000 Calc (admistrator administrator of objects of Eval tag) type ) ensures that all fields of a defined column will have the same value, which corresponds to the value of system variable Sec increased by 1.
A reasonable use of this option is the possibility to use a reference to a column of a structured variable in an expression, where in brackets (row index) is a value of 0. Such reference will be reffered referred to as a reference to a column of a structured variable. This ensures that when evaluating an expression, the value of which is inserted into e.g. 3rd row, all the indeces indices with the constant value of 0 will be replaced with the value of 3.
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| Column | Type | Meaning |
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| ProductsALL | Int | Number of products |
| Rejects | Int | Number of rejects |
| ProductsOK | Int | Number of good-quality products |
Obviously, the following equation can be formed:
ProductsOK = ProductsALL - Rejects
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- Periodically - expression is calculated periodically according to the given period (Period option) and offset (Offset option).
- On change - expression is calculated when a value of at most one object placed in the expression notation, has changed.
- Trigger - definition of a trigger (condition) that causes the expression to be re-evaluated. Object The object representing the trigger may be either of a simple type (unstructured) or a column of a Structured variable object. Object The object may be defined in several ways:
- entering the object name into the input field,
- selection of the object from the list of objects - the list is opened by clicking the button placed right to the input field,
- creating a new object - the button Create a new object.
It is also necessary to determine a given object state when the trigger is valid. The list box placed bellow below the input field to enter the object name contains a list of admissible object value states. This list is different for individual object types. Trigger of expression's re-evaluation will become valid , when the object passes into the selected state. If the option Inverse function is checked, the trigger is valid, when the object is in another state than the selected one.
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Expression evaluation period (hour:min:sec). It is defined only for the periodical evaluation method of an eval tag.
Offset
Time The time offset of the basic time interval (hour:min:sec). It is defined only for the periodical evaluation method of the eval tag.
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The parameter can be defined for the evaluation method On change. It allows to restrict restricting the evaluation of a given expression so that the expression will be evaluated once within the defined time. It is used especially in cases , when the values of the objects defined in the expression are often changed and immediate calculation of the expression is not required.
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