Expression Item General Properties
|Name||The name of the OPC item in the group. There cannot be duplicate names within a group.|
|Value||The static value of this Expression item. This will be overwritten by an Expression/SQL binding.|
|Datatype||The datatype values are stored as.|
Which property of the OPC item you want to use.
- Value - Item value
- Quality - Quality code of the expression/SQL Query (192 = GOOD_DATA)
- Timestamp - The last time the item value changed.
- Name - The SQLBridge Item Name property of this Item.
Options for displaying values based on the Item value.
- Direct Value - Item value
- Hour Meter - Record the amount of time the Item value is non-zero. This accumulation will reset to zero when the item value goes to zero. The datatype should be set to integer or float when using an Hour Meter regardless of the OPC Item type.
On Zero - Use a zero value to accumulate time instead of a non-zero value
Retentive - Retain the Hour Meter value when it is not accumulating.
Units - The time units to display.
- Event Meter - Record the number or times the Item value is non-zero. The datatype should be set to integer when using an Event Meter regardless of the OPC Item type.
On Zero - Use a zero value to accumulate events instead of a non-zero value
|Evaluation Mode||Run-always (ignore Trigger) - When selected, this causes the group to evaluate at each group interval, before the trigger state is evaluated.|
Target Type - This is the selection for what the Item will write to when the group executes.
- None, read-only item - Do not write this value to the database.
- Database field - Write the Item value to the specified column in the database table.
- Other Tag - Write the Expression Item's value back to an OPC item or Tag Reference.
|Target Name||The name of the column in the database that this Item will write to when the group executes. The Target Name list will populate with all the OPC Item and Tag Reference names from this Group, or the column names from the Group's target table depending on the Target Type selected.|
These are the Numeric properties for Expression Items. For a full description, see Tag Scaling Properties.
These are the Alarming settings for the OPC items. See Alarming Properties for a full explanation.
These are the Expression/SQL Query options for Expression Items. See Expression/SQL Properties for a full explanation.