Load Extension Attributes - Metasys - LIT-12011942 - "" - Software Application - Metasys Open Data Server - 10.1

Active Timer

None

Active Timer set

Indicates which Load timer is in effect: Minimum Shed, Maximum Shed, Minimum Release, or None. The Time Remaining attribute indicates how much time remains for the active timer.

Actual Shed Level

0

Indicates the level of power shed when a shed request is active. When the Present Value attribute value is Shed Compliant, the Actual Shed Level equals the value of the Shed Levels array element; otherwise, it equals zero.

Alarm Reference for Ineligibility

C,N,W

Prevents the Load from being shed if the reference is in alarm. This is an optional reference to an object that can be set to any object, including the output object. For example, if the referenced object is a room temperature sensor, and the object goes into alarm (a room becomes too warm), it prevents the supply fan (the Load object) from being shed. If the Load object is already shed when the referenced object goes into alarm, the shed expires as it would normally but cannot be shed again until the referenced object exits the alarm state.

Comfort Override

C,W

Inactive

Comfort Override set

Configures the Comfort Override command behavior for this load. From time to time, you may need to override a load to turn on lights in a normally empty conference room or provide more airflow to a zone. The Comfort Override command is meant for this purpose. You can issue this command directly from DLLR’s Load Summary to release loads if they are shed, and prevent them from being shed. The load cannot be shed again until the Release Comfort Override is issued.

This attribute can be set to the following values:

Inactive—No comfort override is in effect.

Override And Release Immediately—Comfort overrides the Load immediately and prevents it from being shed. If the Load is currently shed, the output write is immediately released.

Override But Release After Timer Expires—Comfort overrides the Load immediately and prevents it from being shed. If the Load is currently shed, the output write is released after the Load’s Minimum Shed Time expires. If the Minimum Shed Time has already expired when the command is issued, the output write is immediately released.

This attribute is synchronized to the Comfort Override/Release Comfort commands.

Current Available Energy Savings

Indicates how much energy would be saved if the Load were shed now.

Display Precision

C,W

10ths

Uses Display Precision (Set 0).

Indicates the rounded position and the number of decimal places to display for this extension.

Display Reference

C,W

Synchronized to the output object’s Display Precision.

Indicates the current display precision of the load’s output object.

Duty Window

W

0

1–65,535

Indicates the time window for determining shed compliance.

Eligibility

Load Eligibility set

Indicates to DLLR whether the Load can be shed and identifies for which strategy or strategies (DL, LR, or both) the Load can be shed.

Event State

Normal, Fault

Determines whether an active event state is associated with this extension. The value is set to Normal when there is no intrinsic alarming defined for this object. If intrinsic alarming is enabled (Enable Intrinsic Alarms = True), then this value is either Normal or Fault (problem occurred with the object subscribing for COVs). This attribute appears on the view when the site is defined as a BACnet site.

Expected Shed Level

0

Indicates the level of power that the Load object expects to shed when a shed request is active or pending. When the Present Value attribute value is Shed Request Pending or Shed Compliant, the Expected Shed Level equals the value of the Shed Levels array element; otherwise, the value of the Expected Shed Level equals zero.

Input Reference

C

Specifies the object and attribute monitored by this extension. The reliability of the Input Reference is monitored and sets the Reliability attribute of this extension.

Last Shed Date

Indicates the date on which the Load was last shed (since download).

Last Shed Time

Indicates the date on which the Load was last shed (since download).

Load Locked

W

False

Specifies whether the Load is locked. A Load that is locked while released cannot be shed until the Load lock is released. A Load that is locked while shed remains shed until the Load lock is released. This attribute is synchronized with the Lock/Unlock commands.

Load Priority

C,W

10

1–10

Indicates how critical the Load’s output is and determines the order in which loads are shed. You can define up to 10 load priorities: Priority 1 through Priority 10. Loads at Priority 10 are first to shed; loads at Priority 1 are the last to shed. The configured Load Priority is shown with the load on the Load Summary of the DLLR object. The shedding order is from top to bottom as listed in the Load Summary when the Load Priority column is sorted with the lowest priority loads listed first.

Load Rating

C,W

Enabled

W

True

Indicates whether the Load object responds to shed requests.

Maximum Shed Time

C,N,W

15

1–65,535

Undefined = 65,535

Units = Minutes

Specifies the maximum number of minutes that a load can be shed before it is automatically released. If the Maximum Shed Time value is not defined, the default value of 65,535 is used. The range is 0 to 65,535 minutes. It is possible for the Load to be released before this time. A Load does not remain shed longer than the maximum shed time unless the load has been locked shed.

Minimum Release Time

C,W

5

1–65,535

Units = Minutes

Specifies the minimum number of minutes that a load must be released from shed before it can be shed again. Although DLLR does not shed a load before this time expires, a load can be manually shed before this value expires.

Minimum Shed Time

C,W

5

1–65,535

Units = Minutes

Specifies the minimum number of minutes that a load must be shed before it can be automatically released. A load can be manually released before this value expires.

On Release

C,W

Release Immediately

Comfort Override Type set

Specifies how soon the Load should be released when a Release Load command is issued or when the Shed command attribute is set to Release. If this attribute is set to Release Immediately, the load releases immediately even if its Minimum Shed Timer is active. If this attribute is set to Release After Timer Expires, the load remains shed until the Minimum Shed Time expires. If a release is issued but the Load remains shed until the Minimum Shed Time expires, the Load’s Shed Status attribute indicates this using one of the following states. The state that is used depends on whether the Load was shed for demand limiting or load rolling.

Shed For DL—Release Issued

Shed For LR—Release Issued

Output Shed Command

Set is specified by output’s States Text attribute.

The state that is written to the output’s Present Value attribute when the Load is shed. DLLR does not shed the Load if the output’s Present Value equals the Output Shed Command value, as no energy would be saved.

Inactive

Uses BACnet Shed State set.

Indicates the current Load shedding state of the Load object.

Rate Units

C,W

kW

Units set

Specifies the energy units used for the Load Rating Energy Savings display.

Reliability

Reliable

Uses Reliability (Set 503).

Represents the reliability of the Present Value. If the Input Reference goes unreliable, the extension monitoring the input goes unreliable.

Requested Shed Level

W

0

1–65,535

Controls the desired level of Load shedding for one shed. Specifying a value greater than the value configured in the Shed Levels attribute sheds to the Shed Levels value. Specifying a value less than the value configured in the Shed Levels attribute (such as zero) cancels a shed.

The DLLR object writes this attribute to one and sheds the Load object. Once the shed completes, the Load object resets this value to zero.

If the Load object sheds through a non-BACnet method, such as the Shed command, the Load sets this attribute to one and returns it to zero after the shed completes.

Shed Command

W

None

Shed Command set

Indicates the current shed/release state of the Load. This attribute also offers the option of shedding or releasing a Load.

Release—Releases the Load. The On Release attribute determines when the Load is released. If the Load is already released, there is no change.

Shed—Immediately sheds a released Load regardless of its Minimum On Time. If the Load is already shed, there is no change.

Shed Duration

W

0

1–65,535

Indicates the number of minutes to shed the Load. Writing this attribute to a value less than the current time minus the Start Time attribute value cancels a shed.

The DLLR object sets this attribute to shed the load. After the shed completes, the Load sets it to zero.

If the Load object sheds through a non-BACnet method, such as the Shed command or Shed Command attribute, it sets this value to the Max Shed Time and returns it to zero when the shed completes. If no Max Shed Time is defined, the Load sets this value to its maximum value (0xFFFF), which is the maximum number of minutes that a Load can shed without being locked shed.

Shed Level Descriptions

Shed All Load

Uses Shed Level Descriptions set.

Provides a description of the shed level supported by the Load object.

Shed Levels

C,W

1

1–65,535

Specifies the shed levels used for the Requested Shed Level attribute. Set this attribute to a value of one (1) for the DLLR to automatically shed the Load. If this attribute is set to another value, the DLLR does not shed or release the Load; although the Load can be shed and released manually or by another feature, the Load is automatically released upon expiration of its Maximum Shed Time, unless the Load is Locked Shed.

Shed Status

Released

Shed Status set

Indicates if the Load is shed or released, and, if shed, which strategy was used to shed the Load (DL or LR).

Shed Ineligibility

Load Ineligibility set

Indicates whether a load is eligible to be shed at the current time, and, if ineligible, the cause of ineligibility.

Shed Strategy

C,W

0

Shed Strategy set

Indicates which strategy is permitted to shed the Load (DL, LR, or both).

Time Remaining

C,W

Indicates how much longer a Load timer is in effect. The Active Timer attribute indicates which timer is in effect.

Start Time

W

BACnet Date Time structure

Indicates the date and time that the Load sheds. Writing this attribute to a wildcard releases a shed load.

The DLLR object sets this attribute to shed the Load. Once the shed completes, the Load object sets the value to date and time wildcards (NONE_FFFF).

If the Load object sheds through a non-BACnet method, such as the Shed command, it sets this attribute to the current time, and returns it to NONE_FFFF after the shed completes.

Status Flags

False, False, False, False

In Alarm, Fault, Overridden, Out of Service

Indicates the general status of the object in BACnet terms and contains four independent states.

The four flags are:

In Alarm—False if the Event State attribute value is Normal; otherwise, the In Alarm flag is True. (Set only by BACnet Intrinsic Alarming.)

Fault—True (1) if the Reliability attribute is not reliable; otherwise, the Fault flag is False.

Overridden—Overridden flag is True if the Present Value is overridden from the hardware source level.

Out of Service—Out of Service flag is True if the Out of Service attribute value is True; otherwise, the Out of Service flag is False.

Units

C,W

IP

SI

Indicates the measurement units of this extension.