Applies toThis topic lists the available transitions for each type of variable.
Bit or Alarm Variables
The expression for bit and alarm variables may contain a number of transitions under which the event may be triggered. The syntax used is as follows:
State1 > State2, State3 > State4, .....StateN-1 > StateN
where 'StateN-1 > StateN' defines a transition from one state to another.
For bits, the states available are:
|
State |
Meaning |
|
0 |
false |
|
1 |
true |
|
S |
significant (valid) |
|
NS |
non-significant (invalid) |
|
ALL |
any State |
For example,: ALL>NS, ALL>1.
For alarms, the available states are:
|
State |
Meaning |
|
S |
significant (valid) |
|
NS |
non-significant (invalid) |
|
ALL |
any state |
|
ACKON |
on and acknowledged |
|
ACKOFF |
off |
|
NOACKON |
on and not acknowledged |
|
NOACKOFF |
off and not acknowledged |
For example,: ACKON>ALL, ACKOFF>ALL.
Text Variables
The expression for a text variable may contain only one transition.
|
Transition |
Meaning |
|
ALL>S |
Transition from any state to a significant (Valid) value. |
|
NS > S |
Transition from a non-significant (Invalid) value to a significant value. |
|
S > S |
All changes of significant value. |
|
S>ALL |
Transition from a significant (Valid) value to any other state. |
|
S > NS |
Transition from a significant value to non-significant (Invalid). |
|
= string |
Equal to the given string. |
|
> string |
The ASCII value of the text variable is greater than that of string. |
|
< string |
The ASCII value of the text variable is less than that of string. |
Register Variables
The expression for a register variable may contain only one transition.
|
Transition |
Meaning |
|
ALL>S |
Transition from any state to a significant (Valid) value. |
|
NS > S |
Transition from a non-significant (Invalid) value to a significant value. |
|
S > S |
All changes of significant value. |
|
S>ALL |
Transition from a significant (Valid) value to any other state. |
|
S > NS |
Transition from a significant value to non-significant (Invalid). |
|
= value |
Equal to "value". |
|
+ value |
The variable increases by an amount equal or greater than value. |
|
- value |
The variable decreases by an amount equal or greater than value. |
|
> value |
The variable is greater than value. |
|
< value |
The variable is less than value. |