BACnet Editor
The BACnet Object Editor allows you to browse, edit, and delete a wide range of BACnet objects in the management station. It also allows you to create new notification class and event enrollment objects. BACnet objects are accessed in the System Browser through the Management View (Field Networks > BACnet Network) or a User-defined View.
For related procedures or workflows, see the step-by-step section.
Prerequisites:
- You have Engineering mode access rights.
- System Manager is in Engineering mode.
The BACnet Object Editor supports many standard BACnet object types and their associated properties. In the BACnet Object Editor, you can create event enrollment and notification class objects. For other BACnet objects, you can use Scheduler for creating schedules, command, and calendar objects, and the Trends application to create trend logs and trend log multiple objects. All other objects are created outside Desigo CC and imported by one of two methods:
- The object is created in the network device and automatically imported with the BACnet Auto-Discovery feature.
- The object is created with the APOGEE Commissioning Tools and imported using the SiB-X Import application.
Default Properties
BACnet objects imported into the Desigo CC system have properties not coming from the system set to common default values and settings, and in many cases no further action is needed other than to specify specific values such as a setpoint, high and low alarm limits, and so on. Likewise, new event enrollment and notification class objects are created with common defaults.
In the following example, the fields in the Definitions section are defaulted to common settings for a new event enrollment object:
By default, the Reference Property and Event Type fields are filtered and provide only the most common options for an event enrollment object. However, by clicking the All check box, an advanced user can select from an unfiltered list of properties.
BACnet Alarming
Two methods of BACnet alarming are available: intrinsic and event enrollment (algorithmic change reporting).
Intrinsic Alarming
Intrinsic alarming is relatively simple. The object is defined as alarmable and configured with a few basic user-supplied alarm criteria. See the following table to see which BACnet objects support intrinsic alarming.
BACnet Objects Supported by BACnet Object Editor | ||||
Object | Intrinsic |
| Object | Intrinsic Alarming |
Accumulator | Yes |
| Integer Value | Yes |
Alert Enrollment | Yes |
| Large Analog | Yes |
Analog Input | Yes |
| Life Safety Point | Yes |
Analog Output | Yes |
| Life Safety Zone | Yes |
Analog Value | Yes |
| Load Control | Yes |
Binary Input | Yes |
| Loop | Yes |
Binary Output | Yes |
| Multistate Input | Yes |
Binary Lighting | Yes |
| Multistate Output | Yes |
Binary Value | Yes |
| Multistate Value | Yes |
Bit String Value | Yes |
| Network Security | No |
Calendar | No |
| Notification Class | No |
Character String | Yes |
| Notification Forwarder | No |
Command | No |
| Octet String Value | No |
Date Pattern Value | No |
| Positive Integer | Yes |
Date Time Pattern | No |
| Program | No |
Date Value | No |
| Pulse Converter | Yes |
Device | No |
| Schedule | No |
Event Enrollment | No |
| Structured View | No |
Event Log | Yes |
| Time Value | No |
File | No |
| TrendLog | Yes |
Global Group | Yes |
| TrendLog Multiple | Yes |
Group | No |
| — | — |
Event Enrollment (Algorithmic Change Reporting)
Event enrollment is an enhanced alarming feature more flexible and powerful than intrinsic alarming. It employs an event enrollment object (stored separately from the BACnet object being monitored) which can be combined with a notification class object to provide multiple messages to multiple locations (devices).
BACnet objects can have one or more event enrollment objects associated with them. However, an event enrollment object can only be associated with one BACnet object.
Algorithmic change reporting uses an event enrollment object, which references another source object, to generate alarm or event notifications. A property of the referenced object is applied to a standard algorithm (event type) to determine if there should be a change report. Occurrences of change are then reported to destinations based on a notification class object. For example, changes to the value of a referenced object can trigger event notifications to be sent to multiple management stations.
The following event-type algorithms are specified in the BACnet standard:
BACnet Event Type Algorithms | ||
Event Type | Parameters | Description |
CHANGE_OF_BITSTRING |
| Occurs when the value of the referenced property becomes equal to one of the values contained in the List_Of_Bitstring_Values. This event type generates a TO-OFFNORMAL transition and is cleared when the value of the referenced property is no longer equal to one of the value contained in the List_Of_Bitstring_Values. |
CHANGE_OF_STATE |
| Occurs when the value of the referenced property becomes equal to one of the values contained in the List_Of_Value, and this value remains equal for Time_Delay seconds. The type of event may only be applied to properties that have discrete or enumerated value, including Boolean. This event type generates a TO-OFFNORMAL transition. |
CHANGE_OF_VALUE |
| Occurs when the absolute value of a referenced property changes by an amount equal to or greater than the Referenced_Property_Increment, and this condition remains for Time_Delay seconds. This event type generates TO-NORMAL transitions. |
COMMAND_FAILURE |
| Occurs if the values of the referenced property and the Feedback_Property_Reference disagree for a time period greater than the Time_Delay parameter. It may be used to verify that a process change has occurred after writing to a property. The type of event only applies to properties that take on discrete value. This event type generates a TO-OFFNORMAL transition. |
FLOATING_LIMIT |
| Occurs if the referenced property leaves a range of values determined by the current value of the Set_Reference, High_Diff_Limit, Low_Diff_Limit, and Deadband. This type of event generates a TO-NORMAL transition. |
OUT_OF_RANGE |
| Occurs if the referenced property leaves a range of values defined by the High_Limit and Low_Limit parameters and remains there for Time_Delay seconds. If the transition is to a value above the High_Limit or below the Low_Limit, the object generates a TO-OFFNORMAL transition. |
BUFFER_READY |
| Occurs when a number of records specified by the Notification_Threshold have been entered into the log since the start of operation or the previous notification, whichever is most recent. This type of event generates a TO-NORMAL transition. |
UNSIGNED_RANGE |
| Occurs if the referenced property leaves the range of values from Low_Limit through High_Limit parameters and remains there for Time_Delay seconds. This type of event generates a TO-NORMAL transition. |
CHANGE_OF_LIFE_SAFETY |
| Occurs when the value of the referenced property becomes equal to any of the values in the List_Of_Life_Safety_Alarm_Values and remains within the set of values in the list for Time_Delay seconds. This type of event generates a TO_OFFNORMAL transition. |
DOUBLE_OUT_OF_RANGE |
| 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 |
| 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. A "match" of the monitored value with an alarm value is defined as follows: |
For more information about BACnet algorithmic change reporting, see Section 13.3 of the ANSI/ASHRAE Standard 135-2008 (or later) and the documentation provided by the manufacturer of the BACnet device (field panel) providing the algorithmic change reporting.
Copying Alarms to Other Objects
The Copy All feature allows you to copy the intrinsic alarm and the associated event enrollment objects of a selected object to one or more target objects. This process creates new event enrollment objects for each target object, and overwrites the intrinsic alarm properties of the target objects with the intrinsic alarm properties of the selected object.
You can begin a copy procedure and then work with any other management station features, since the Copy All feature runs in the background. This includes starting a second alarm copy operation.
A notification class object is required for both types of BACnet alarming. It directs alarm or event notifications to specific recipients (devices or management stations). This object also defines which alarm and event notifications a device can receive, the priorities of the event-notification messages, and whether acknowledgments are required.
The following table shows specification suggestions for priority ranges:
Notification Class Priority Ranges | ||
Message Group | Priority Range | Network Priority |
Life Safety | 00 – 31 | Life Safety Message |
Property Safety | 32 – 63 | Life Safety Message |
Supervisory | 64 – 95 | Critical Equipment Message |
Trouble | 96 – 127 | Critical Equipment Message |
Miscellaneous Higher Priority Alarm and Events | 128 - 191 | Urgent Message |
Miscellaneous Lower Priority Alarm and Events | 192 – 255 | Normal Message |
The Copy All feature overwrites the intrinsic alarm information of the target objects. If the notification class object in the source object does not exist in the target object, then a notification class object is created.
