This DataType is a union that represents the event parameter. Its composition is formally defined in Table 236. If the event parameter is None-event, the value is set to NULL. Event state transitions are also indicated if the value of the mode parameter changed since the last transition indicated. In this case, any time delays are overridden and the transition is indicated immediately.

Table 236 – BACnetEventParameter Structure

Name

Type

Description

BACnetEventParameter

union

Change-of-bitstring

BACnetEventParameterChangeOfBitstring

The CHANGE_OF_BITSTRING event algorithm detects whether the monitored value of type BIT STRING equals a value that is listed as an alarm value, after applying a bitmask.

Change-of-state

BACnetEventParameterChangeOfState

The CHANGE_OF_STATE event algorithm detects whether the monitored value equals a value that is listed as an alarm value. The monitored value may be of any discrete or enumerated data type, including Boolean.

Change-of-value

BACnetEventParameterChangeOfValue

The CHANGE_OF_VALUE event algorithm, for monitored values of datatype REAL, detects whether the absolute value of the monitored value changes by an amount equal to or greater than a positive REAL increment.

Command-failure

BACnetEventParameterCommandFailure

The COMMAND_FAILURE event algorithm detects whether the monitored value and the feedback value disagree for a time period. It may be used, for example, to verify that a process change has occurred after writing a property.

Floating-limit

BACnetEventParameterFloatingLimit

The FLOATING_LIMIT event algorithm detects whether the monitored value exceeds a range defined by a setpoint, a high difference limit, a low difference limit and a deadband.

Out-of-range

BACnetEventParameterOutOfRange

The OUT_OF_RANGE event algorithm detects whether the monitored value exceeds a range defined by a high limit and a low limit. Each of these limits may be enabled or disabled. If disabled, the normal range has no higher limit or no lower limit. In order to reduce jitter of the resulting event state, a deadband is applied when the value is in the process of returning to the normal range.

Extended

BACnetEventFaultParameterExtended

The EXTENDED event algorithm detects event conditions based on a proprietary event algorithm. The proprietary event

algorithm uses parameters and conditions defined by the vendor. The algorithm is identified by a vendor-specific event type that is in the scope of the vendor's vendor identification code. The algorithm may, at the vendor's discretion, indicate a new event state, a transition to the same event state, or no transition to the Event-State-Detection. The indicated new event states may be NORMAL, and any OffNormal event state. FAULT event state may not be indicated by this algorithm. For the purpose of proprietary evaluation of unreliability conditions that may result in FAULT event state, a FAULT_EXTENDED fault algorithm shall be used.

Buffer-ready

BACnetEventParameterBufferReady

The BUFFER_READY event algorithm detects whether a defined number of records have been added to a log buffer since start of operation or the previous notification, whichever is most recent.

Unsigned-range

BACnetEventParameterUnsignedRange

The UNSIGNED_RANGE event algorithm detects whether the monitored value exceeds a range defined by a high limit and a low limit.

Double-out-of-range

BACnetEventParameterDoubleOutOfRange

The DOUBLE_OUT_OF_RANGE event algorithm detects whether the monitored value exceeds a range defined by a high limit and a low limit. Each of these limits may be enabled or disabled. If disabled, the normal range has no lower limit or no higher limit respectively. In order to reduce jitter of the resulting event state, a deadband is applied when the value is in the process of returning to the normal range.

Signed-out-of-range

BACnetEventParameterSignedOutOfRange

The SIGNED_OUT_OF_RANGE event algorithm detects whether the monitored value exceeds a range defined by a high limit and a low limit. Each of these limits may be enabled or disabled. If disabled, the normal range has no lower limit or no higher limit respectively. In order to reduce jitter of the resulting event state, a deadband is applied when the value is in the process of returning to the normal range.

Unsigned-out-of-range

BACnetEventParameterUnsignedOutOfRange

The UNSIGNED_OUT_OF_RANGE event algorithm detects whether the monitored value exceeds a range defined by a high limit and a low limit. Each of these limits may be enabled or disabled. If disabled, the normal range has no lower limit or no higher limit respectively. In order to reduce jitter of the resulting event state, a deadband is applied when the value is in the process of returning to the normal range.

Change-of-characterstring

BACnetEventParameterChangeOfCharacterString

The CHANGE_OF_CHARACTERSTRING event algorithm detects whether the monitored value matches a character string that is listed as an alarm value. Alarm values are of type BACnetOptionalCharacterString, and may also be NULL or an empty character string.

Change-of-life-safety

BACnetEventParameterChangeOfLifeSafety

The CHANGE_OF_LIFE_SAFETY event algorithm detects whether the monitored value equals a value that is listed as an alarm value or life safety alarm value. Event state transitions are also indicated if the value of the mode parameter changed since the last transition indicated. In this case, any time delays are overridden and the transition is indicated immediately.

Its representation in the AddressSpace is defined in Table 237.

Table 237 – BACnetEventParameter Definition

Attributes

Value

BrowseName

BACnetEventParameter

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

Other

Subtype of Union defined in OPC 10000-5.