User Manual

Calendars and schedulers
Schedule
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The switching value is output to [PrVal] and to the objects to be switched
(commanded objects list). A schedule block can only contain switching values
of the same data type (binary or analog or multistate or boolean or unsigned or
real or enumerated). It is therefore not possible to switch two different data
types in sequence.
In Desigo PX the CAL (calender) and SCHED (schedule) function blocks can be
created online.
Commanded objects
The schedule can influence other commandable objects, irrespective of
whether or not they are in the same automation station.
The schedule is thus a grouping object and contains a list of group members, in
the form of a list of name references [NamrList]. These group members are the
commanded objects, that is, the objects to be switched. The list can contain up
to five entries.
The referencing of group members is resolved at runtime.
The grouping and the information flow only go in one direction (forward
referencing).
The information flows inside one automation station or across several
automation stations. The scheduler object recognizes the flow of information
and knows where to send information and what data type is required by the
group members. The information transmitted covers only the present value
[PrVal] or the values for the Optimum Start/Stop functions [PrVal], [NxVal] and
[NxTi].
In Desigo PX the function block variable Heartbeat [Hrtbt] determines the
period measured in seconds at which the current value (Present_Value) is
written.
In Desigo PX the function block variable Enable_Repeat_Command [EnRptCmd]
defines if the switching action is executed if the Present_Value does not
change:
● EnRptCmd = TRUE: Switching action is executed if Present_Value does not
change.
● EnRptCmd = FALSE: Switching action is NOT executed if Present_Value
does not change.
Referencing
Information flow
Heartbeat [Hrtbt]
Enable_Repeat_
Command [EnRptCmd]