FieldServer FS-8700-73 - Manual (Page 24)

FS-8700-73 BACnet MSTP Driver Manual Page 24 of 48
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Appendix A.6.3. Using Intrinsic Reporting for a Multistate Value
To use Intrinsic Reporting for a Multistate value, it is necessary to classify each of the states as either Normal,
Alarm or Trouble. This is done by adding another column to the Offset_Table, called Table_User_Value. Each state
is then classified by inserting one of the following values in its row:
0 = normal
1 = alarm
2 = fault
//set up a look up table
Offset_Table
Offset_Table_Name , Table_String , Table_Index_Value , Table_User_Value
FIRE_ALRM_TEXT , SYSTEM READY , 1 , 0
FIRE_ALRM_TEXT , ALARM , 2 , 1
FIRE_ALRM_TEXT , MAINTENANCE , 3 , 2
FIRE_ALRM_TEXT , OFF-LINE , 4 , 2
FIRE_ALRM_TEXT , IN SERVICE , 5 , 0
FIRE_ALRM_TEXT , OTHER , 6 , 2
Note: The state value (Table_Index_Value) is an enumerated value between 1 and 16. Zero is not a valid value, but
since many client side configurations will wake up with values of zero, the BACnet server will treat a value of zero
as a normal value (i.e. not as an alarm or fault value)
Appendix A.7. COV and Intrinsic Reporting
The COV (Change of Value) and Intrinsic Reporting services are two distinct ways in which point values can be
reported to a client workstation as they change, i.e. in an event-driven opposed to a polling method. This can
increase performance dramatically compared to polling method alone. It also reduces network traffic significantly.
For BACnet/MSTP, only MSTP Master Nodes support COV and Intrinsic Reporting
The services are suited to different purposes:
COV is suited to value updates. On analog points the sensitivity can be set using the COV_Increment property.
Only changes larger than the COV_Increment value will be reported.
Intrinsic Reporting is used for alarming. It is implemented via Notification_Class objects, which can receive
subscriptions from client workstations that add themselves to the RecipientList property of a
Notification_Class
object. Notifications are done using ConfirmedEventNotification or
UnconfirmedEventNotification. Intrinsic Reporting also allows for alarms to be acknowledged (using the
AcknowledgeAlarm service) and for all subscribed client workstations to be notified of alarm
acknowledgements (using EventNotifications of type ACK_NOTIFICATION)..
Appendix A.7.1. Notes on COV configuration:
COV functionality is not enabled by default for MSTP. The Node_Option parameter can be configured to
enable or disable COV. An example configuration is presented in Appendix A.7.4. Systems using