User Manual

Calendars and schedulers
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10
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10 Calendars and schedulers
Standard BACnet objects
The standard BACnet objects Schedule and Calendar are used for time scheduling functions in the Desigo
system. These objects can be used to configure and operate time scheduling functions at different
operating levels within the system and via BACnet-compatible operator units from other manufacturers.
The local PXM10 operator unit can also be used to operate the standard BACnet objects for the connected
automation stations and PXC.
Function blocks
The time scheduling functions are implemented as function blocks in CFC charts of automation stations.
Each automation station and each switching operation requires one schedule block. The pins of the
function blocks are mapped to standard BACnet properties.
There are four versions of the schedule block, with an analog, binary or multistate output or with a variable
data type (Boolean, Unsigned, Real or Enumerated). A schedule block can only contain schedule values of
the same data type.
[WeekSchd] [EcptSchd]
The scheduler program consists of a weekly schedule [WeekSchd] and an exception schedule [EcptSchd].
The weekly schedule contains a 24-hour profile for each day. The exception schedule contains up to 20
profiles, which can be activated for a date or date range. The date or date range can be defined both in the
schedule itself and in the calendar object.
[Prio]
A priority must be assigned to each of the profiles in the schedule. Based on the priority level assigned, the
scheduler program determines from the priority [Prio] which profile is to be processed. The weekly
schedule has the lowest priority.
[EfPrd]
The effective period [EfPrd] property defines the time period for which the schedule is active.
[PrVal] [NxVal] [NxTi]
The present value [PrVal], next value [NxVal] and next time [NxTi] are available at the output of the time
schedule. [NxVal] and [NxTi] are used for optimization purposes.
Commanded objects
The time schedule also incorporates a list of references to BACnet objects and (optionally) a property
which is to be controlled by the scheduler program via BACnet.
[DefVal]
The BACnet property Relinquish_Default is the default value [DefVal] for the present value output [PrVal].