It represents four 0:Boolean flags that represent the general health of an analog input. The flags are IN_ALARM, FAULT, OVERRIDDEN, and OUT_OF_SERVICE.
When the Enable value is true, logging is enabled. When the Enable variable value is false, logging is not enabled. Logging occurs if and only if the Enable variable value is true and the device Local_Time.
The Start_Time value indicates the date and time at or after which logging shall be enabled by this variable. The variable is O, and if unspecified is ignored for the purpose of determining whether or not logging is enabled. If Start_Time specifies a time and date that is equal to or later than the Stop_Time then logging shall be disabled.
The Stop_Time value indicates the date and time at or after which logging shall be disabled by this variable. The variable is O, and if unspecified is ignored for the purpose of determining whether or not logging is disabled. If Stop_Time indicates a date and time that is earlier than the Start_Time, then logging is disabled.
When the Stop_When_Full value is true, logging shall cease when the serialization buffer is full. When logging ceases because the next event would fill the buffer, an event indicating that the buffer is full is logged and the Enable variable shall be set false.
The Buffer_Size value indicates the number of records that may be contained by the buffer.
The Record_Count value indicates the number of records that are currently present in the buffer. When a value of zero is written to this variable, all records in the buffer shall be deleted and the Records_Since_Notification variable value shall be reset to zero.
The Total_Record_Count value indicates the total number of records that have been logged since the object was created. When the count is incremented past the maximum 32-bit integer value, the next value of the variable shall be 1.
The Records_Since_Notification indicates the number of records that have been logged since the buffer was last cleared (notification), or since the beginning of the logging process if no notification has been delivered.
The FaultEvaluation Object contains status and configuration information for the fault evaluation of the BACnetLoopType. The BACnetFaultEvaluationType is defined in 8.23. The Object is optional and is not present if fault evaluation is not activated for the BACnet object.
The EventReporting Object contains status and configuration information for the event reporting of BACnetTrendLogType. The BACnetEventReportingType is defined in 8.8. The Object is optional and is not present if event generation is not activated for the BACnet object.
The EventAlgorithm component is changed to TypeDefinition BACnetFloatingLimitAlgorithmType and ModellingRule Mandatory if used in the BACnetLoopType. The BACnetBufferReadyAlgorithmType is defined in 8.14.
The Properties TimeDelay and TimeDelayNormal are set to 0 and shall be read only since they do not exist on a BACnet Trend Log object.
On the EventAlgorithm instance of the BACnetBufferReadyAlgorithmType the BACnet property Notification_Threshold is mapped to Threshold. The BACnet property Last_Notify_Record is mapped to PreviousCount.