If your database contains Data Grid items, you can reference their cells in expressions. You can reference an individual cell or you can reference a range of cells (an array).
NOTE: Data Grid expressions do not support indirect tags.
The grammar for data grid expressions is an extension of the grammar for Standard Expressions :
<cell> <field><row>
<cell-block> <field><row> ":" <field><row>
Where:
- <cell> or <cell-block> is a <factor> in the definition of <term> (see Standard Expressions ).
- <field> is a field in the data grid
- <row> is a row in the data grid.
NOTE: All functions support values from single cells, but only the AVERAGE, MAX, MIN, PRODUCT, and SUM functions support values from blocks of cells.
Example:
Referencing single cells:
DATA1 + DATA5
This calculates the sum of the values that are stored in row 1 and row 5 of the field named DATA.
Referencing a block of cells from the same field:
MAX(DATA1:DATA6)
This calculates the maximum value of the values that are stored in rows 1 to 6 inclusive of the field named DATA.
Referencing a block of cells from different fields:
AVERAGE(A1:C6)
This calculates the average value of the values that are stored in the cells between row 1 of the field named A and row 6 of the field named C. The same expression could be defined as AVERAGE(C6:A1) as ClearSCADA automatically determines the range of cells, even if the last cell is defined first.
NOTE: Be careful to avoid recursive expressions that create circular references, for example, A1 = B1 + C1, B1 = A1 + D1.