User Manual

Calendars and schedulers
Alarm message texts
10
CM110664en_07 165 | 353
10 Calendars and schedulers
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.
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.
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.
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.
The effective period [EfPrd] property defines the time period for which the
schedule is active.
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.
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.
The BACnet property Relinquish_Default is the default value [DefVal] for the
present value output [PrVal].
Standard BACnet
objects
Function blocks
[WeekSchd] [EcptSchd]
[Prio]
[EfPrd]
[PrVal] [NxVal] [NxTi]
Commanded objects
[DefVal]