The following examples show different conditions for a data event trigger.
Example: Greater than and Tolerance Range
For a data event trigger using the Greater
than condition, the trigger will execute every
time the device variable is greater than the defined
value.
You can use the On Edge option with a
corresponding Tolerance Range to limit the
overall condition being met to include the concept of
resetting the event condition.
Example: The condition is Greater
than, the value is 10, and a tolerance range of
3.
Explanation:
- The trigger will execute when the condition is true, Local CPU1.D[5] > 10.
- Since a tolerance range is used, the trigger will not execute again until it is reset.
- The trigger will reset when the Local CPU 1.D[5]
reaches the condition value minus the tolerance range
value, which in this case is 7 (10 minus 3).
The following illustrates Greater than,
the value is 10, and a tolerance range of 3:
Where:
-
are sampled
values of Local CPU 1.D[5]. - Event indicates the trigger will execute.
- Reset indicates the trigger event condition has
been reset and the trigger will execute again when
Local CPU 1.D[5] > 10.
If you do not specify a Tolerance Range or a Deadband Range with the Greater than condition, the trigger will execute every time the variable is greater than the defined value.
Example: Less than and Tolerance Range
For a data event trigger using the Less
than condition, the trigger will execute every
time the device variable is less than the defined
value.
You can use the On Edge option with a
corresponding Tolerance Range to limit the
overall condition being met to include the concept of
resetting the event condition.
Example: The condition is Less
than, the value is 10, and a tolerance range of
3.
Explanation:
- The trigger will execute when the condition is true, Local CPU1.D[5] < 10.
- Since a tolerance range is used, the trigger will not execute again until it is reset.
- The trigger will reset when the Local CPU 1.D[5]
reaches the condition value plus the tolerance range
value, which in this case is 13 (10 plus 3).
The following illustrates Less than, the value is 10, and a tolerance range of 3.
Where:
-
are sampled
values of Local CPU 1.D[5].
- Event indicates the trigger will execute.
- Reset indicates the trigger event condition has
been reset and the trigger will execute again when
Local CPU 1.D[5] < 10.
If you do not specify a Tolerance Range or a Deadband Range with the Less than condition, the trigger will execute every time the variable is less than the defined value.
Example: Equal to
For a data event trigger using the Equal
to condition, the trigger will execute every time
the device variable is equal to the defined value.
Example: The condition is Equal
to and the value is 10.
Explanation:
- In the case of an Equal to
condition, the event condition will be reset on either
side of the condition.
Note that On Edge is always on when the condition is set to Equal to.
The following illustrates Equal to and
the value is 10.
Where:
-
are sampled
values of Local CPU 1.D[5].
- Event indicates the trigger will execute.
- The condition resets when D[5] = 10.
Example: Greater than and Deadband Range
For a data event trigger using the Greater
than condition, the trigger will execute every
time the device variable is greater than the defined
value.
You can use the On Edge option with a
corresponding Deadband Range to limit the
overall condition being met to include the concept of
resetting the event condition.
Example: The condition is Greater
than, the value is 100, and a deadband range of
2.
Explanation:
- If Local CPU 1.D[5] = 101, then the trigger will
execute since the condition is true.
Then if Local CPU1.D[5] assumes another value where current Local CPU 1.D[5] - previous Local PU 1.D[5] > 2, the trigger will execute.
The following illustrates Greater than,
the value is 100, and a deadband range of 2.
If you specify a Deadband Range value
instead of a Tolerance Range value, the
trigger will execute if the difference between any 2
successive values exceeds the deadband range value. The
deadband range value is an absolute value and not a
percentage.