Optimal Start Attributes - Metasys - LIT-12011964 - Software Application - System Configuration Tool - 13.2

Metasys SCT: System Configuration Tool Help

Brand
Metasys
Product name
System Configuration Tool
Document type
User Guide
Document number
LIT-12011964
Version
13.2
Revision date
2020-01-21
Language
English

This object contains attributes common to many Metasys system objects. These common attributes are described in the Common Object Attributes section.

Table 1. Optimal Start Object Attributes
Name / View Group

Attribute ID Writable (W) Configurable (C)

Attribute Description

Enabled -- Object

673 W C

Indicates whether the Multiple Command object is enabled or disabled

OST Type -- Object

933 W C

Defines the OST supported configuration. When the zone is in a mode not supported by the OST object, the Present Value is idle. OST-supported modes include:

  • Heating and Cooling

  • Heating Only

  • Cooling Only

Adaptation Enabled -- Control

934 W C

Indicates whether OST uses adaptive learning to change the building heating and cooling constants and heating and cooling deadtimes.

Zone Schedule Obj -- Control

963 W C

Identifies the Schedule object, which schedules the Zone Occ Mode Obj. This object must be defined in the schedule and have valid start and stop times for the current day in order for OST to run. Otherwise, the OST object’s Present Value is Not Operational. Only one Start and Stop time can be defined per day, and the Start time must precede the Stop time. The Start time must be defined as binary State ON (1) and Stop time must be defined as binary State OFF (0).

Zone Occ Mode Obj -- Control

935 W C

Identifies the object used to command a zone to occupied or unoccupied. This object must be specified in the Zone Schedule Obj. This is commanded by scheduling to occupied and by OST if prestop is enabled.

Note: If the Zone Occ Mode Obj and the Warmup/Cooldown Mode Obj are the same point, then the point is commanded by the Scheduling at the scheduled time.

Zone WC Mode Obj -- Control

936 W C

Identifies the object used to command a zone to Warmup or Cooldown mode. This object may be the same as the Zone Occ Mode Obj. This object is commanded by the OST at the optimal start time. This object is released at the occupied time unless this object is also the value for the Zone Occ Mode Obj.

Heating Setpoint -- Control

937 W C

Identifies the attribute of an object used to define the zone occupied target heating temperature. This attribute may be the same as the Cooling Setpoint attribute.

Cooling Setpoint -- Control

939 W C

Identifies the attribute of an object used to define the zone occupied target cooling temperature. This attribute may be the same as the Heating Setpoint attribute.

Zone Temperature -- Control

941 W C

Identifies the attribute of an object used to determine the zone temperature.

Outdoor Air Temp -- Control

32092 W C

Identifies the attribute of an object used to determine the outdoor temperature:

  • If this attribute is not defined, or is offline, the outdoor air temperature is not used in the OST calculations and is assumed to be within the design temperatures.

  • If an Analog attribute reference is defined for the outdoor air temperature, it aids in determining if the Optimal Start object should adapt constants and deadtimes.

  • If the attribute is defined and outside the design temperatures, deadtime and constant calculations are skipped.

  • If the attribute is defined and is outside the design temperatures during Prestart, the optimal start time is set to early start time.

  • If the attribute is defined and outside the design temperatures during Prestop, do not Prestop.

Cooling Design Temp -- Setup

943 W C

Indicates the highest outside temperature at which the cooling system maintains zone comfort in the cooling mode.

Heating Design Temp -- Setup

944 W C

Indicates the lowest outside temperature at which the heating system maintains zone comfort in the heating mode.

Cooling Constant -- Setup

945 W C

Defines the rate at which the zone cools down after equipment startup. If adaptation is enabled, this constant is adapted without user intervention. If adapting and the OST object Cooling Setpoint and Heating Setpoint attributes reference the same object on a field controller, then the cooling constant is adapted even if the mode is not cooling, meaning both constants change.

Cooling Deadtime -- Setup

948 W C

Indicates the time required after startup to lower the temperature by one degree. This value is adapted by the OST algorithm, if adaptation is enabled. If adapting, cooling, and heating setpoints are the same attribute, the Cooling Deadtime is adapted even if the mode is not cooling, meaning both deadtimes change.

Heating Constant -- Setup

946 W C

Defines the rate at which the zone heats up after equipment startup. If adaptation is enabled, this constant is adapted without user intervention. If adapting and the OST object Cooling Setpoint and Heating Setpoint attributes reference the same object on a field controller, then the heating constant is adapted even if the mode is not heating, meaning both constants change.

Heating Deadtime -- Setup

947 W C

Indicates the time required after startup to raise the temperature by one degree. This value is adapted by the OST algorithm, if adaptation is enabled. If adapting, cooling, and heating setpoints are the same attribute, the Heating Deadtime is adapted even if the mode is not heating, meaning both deadtimes change.

Min Prestart Time -- Setup

949 W C

Indicates the minimum period of time before occupancy to start the heating/cooling system. This time allows for the required amount of air changes in the zone prior to occupancy (latest optimal start time).

Max Prestart Time -- Setup

954 W C

Indicates the maximum period of time required to bring the zone up to occupancy setpoint temperature under the worst conditions (earliest optimal start time).

Max Prestop Time -- Setup

957 W C

Indicates the maximum period of time that the heating/cooling system can be shut down and still maintain the occupied zone temperature until entering the unoccupied mode (earliest optimal stop time). By setting this time to zero (the default value), optimal stop is disabled.

Temp Differential -- Setup

962 W C

Indicates the value added and subtracted to the zone setpoint to define a temperature range.

Display Precision -- Setup

661 W C

Indicates the rounded position and decimal places to display for this object.

Temperature Units -- Setup

972 C

Indicates the units associated with the attributes for temperatures.

Relative Temp Units -- Setup

2167 C

Specifies the units associated with the Temp Differential attribute.