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Elements of filter formulas, Table 7-2, Elements of filter formulas -9 – SMC Networks EliteView 6.20 User Manual

Page 93

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D

EFINING

F

ILTER

F

ORMULAS

7-9

Logical_Operator – Legal values include:

AND

– Both expressions must be true to meet a given condition

OR

– One true expression is enough to meet a given condition

Elements of Filter Formulas

Notes: 1. The equal to (==) and unequal (!=) expressions follow C language syntax.

2. If more than one expression is used to define a filter, first enclose each expression in parentheses and

then combine them with AND or OR. Parentheses are used to maintain the order of evaluation.
Otherwise conditions are evaluated from left to right.

3. If you want to test a log process without saving data into the database, set the filter formula to an

impossible condition; for example, (TIME<000000).

Table 7-2 Elements of Filter Formulas

Parameter

Example

Description

Variable

VALUE

Value of the data

Date when the value is reached

Time when the value is reached

Relation

>

<

>=

==

!=

Greater than

Less than

Greater than or equal to

Less than or equal to

Not equal

Value

256

200040520

132201

Positive number (4 byte unsigned integer)

Date format (YYYYMMDD) for 20 March 2004

Time format (HHMMSS) for 01:55:01pm

Logical_Operator

AND

OR

Both statements must be true

Either statement may be true