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To set up the driver
Number of poll retries before
Network Input Microblocks
indicate failure
Periodic rebinding interval
BACnet COV Throttling
Enable COV Throttling
Trend Sampling
Collect a daily midnight
sample for all points in this
controller that are sampling
on COV
Notification Classes
Alarms in the i-Vu® application use Notification Class #1. A BACnet alarm's Notification Class defines:
Alarm priority for Alarm, Fault, and Return to Normal states
Options for BACnet alarm acknowledgment
Where alarms should be sent (recipients)
Priorities
Chilled Water System Optimizer v2
Installation and Start-up Guide
The maximum number of retries after the initial attempt that a Network
microblock will attempt to communicate with its target device. If unsuccessful, the
point will transition to an idle state for 30 seconds before attempting to
communicate again. Change this field only if directed by Technical Support.
If a microblock uses a wildcard in its address, this timer determines how often the
microblock will attempt to find the nearest instance of its target. For example, if
an outside air temperature address uses a wildcard, a VAV application will look for
the outside air temperature on the same network segment or on the nearest
device containing that object.
Under normal circumstances, COV Throttling should be enabled to prevent
excessive network traffic if an object's COV Increment is set too low. See
EXCEPTION below.
When enabled, if an object generates excessive COV broadcasts (5 updates in 3
seconds), the driver automatically throttles the broadcasts to 1 per second. Also,
if the object's value updates excessively for 30 seconds, an alarm is sent to the i-
Vu® application listing all objects that are updating excessively. A Return-to-
normal alarm is sent only after all objects have stopped updating excessively.
EXCEPTION: In rare circumstances, such as process control, a subscribing object
may require COV updates more frequently than once per second. For these
situations, clear this checkbox, but make sure that your network can support the
increased traffic. You will also need to disable the Excessive COV alarms under
the driver's Common Alarms.
For values that change infrequently, select to verify at midnight daily that the
point is still able to communicate trend values.
NOTE BACnet defines the following Network message priorities for Alarms and
Events.
Priority range
Network message priority
00–63
Life Safety
64–127
Critical Equipment
128–191
Urgent
192–255
Normal
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