Если item выходит за рамки timeout, он становится unsupported.
Кстати, в версии 3.2 все немного по-другому:
5.17 Trigger functions
Several functions are now calculated for unsupported items as well:
nodata()
date()
dayofmonth()
dayofweek()
now()
time()
Host and item, however, must be enabled as before.
5.18 Unsupported items and unknown values in triggers/calculated items
Previously any unsupported item in trigger expression or error in function evaluation immediately rendered the whole expression value to Unknown. Triggers became Unknown, calculated items became unsupported.
In the new version there's a more flexible approach: unsupported items and errors in function evaluation continue to take part in expression evaluation as unknowns.
Advantage - logical OR and AND expressions are evaluated, if possible, to known values. For example:
'1 or Unsuported_item1.some_function()' is evaluated to '1' (True)
'0 and Unsuported_item1.some_function()' is evaluated to '0' (False)
See Expressions with unsupported items and unknown values.
Кстати, в версии 3.2 все немного по-другому:
5.17 Trigger functions
Several functions are now calculated for unsupported items as well:
nodata()
date()
dayofmonth()
dayofweek()
now()
time()
Host and item, however, must be enabled as before.
5.18 Unsupported items and unknown values in triggers/calculated items
Previously any unsupported item in trigger expression or error in function evaluation immediately rendered the whole expression value to Unknown. Triggers became Unknown, calculated items became unsupported.
In the new version there's a more flexible approach: unsupported items and errors in function evaluation continue to take part in expression evaluation as unknowns.
Advantage - logical OR and AND expressions are evaluated, if possible, to known values. For example:
'1 or Unsuported_item1.some_function()' is evaluated to '1' (True)
'0 and Unsuported_item1.some_function()' is evaluated to '0' (False)
See Expressions with unsupported items and unknown values.
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