It is normal for a BACnet network port's Poll Service 'Busy Time' property to be greater than 100%?

[Product_Support]

Issue

It is normal for a BACnet network port's Poll Service 'Busy Time' property to be greater than 100%?

Eg:

Product Line

I/A Series

Environment

G3 BACnet

Cause

The Poll Service is a common component for typical field bus drivers including BACnet. 

The Niagara Ax Drivers Guide defines the Poll Service's Busy Time property as:

Displays a percentage of time spent by the poll thread actually polling points, across all poll buckets. Includes (in parentheses) a ratio of “(time spent polling/total time since statistics were restarted)”. Given a small amount of time is spent transitioning between poll buckets, and with the thread sleeping to evenly space out polling messages, it is unlikely to ever see Busy Time reach exactly 100%. However, any percentage above 95% indicates that the poll thread is basically spending all of its time actually polling. 

Resolution

In the case of the Poll Service for a BACnet network port, because two threads are used for polling, it is possible to see a Busy Time approaching 200%. In this case, divide the Busy Time in half to get an average busy time for each thread.

In the case of the Poll Service for a Bacnet network port, because two threads are used for

polling, it is possible to see a Busy Time approaching 200%. In this case, divide the Busy Time in half

to get an average busy time for each thread.

actually polling.

However, any percentage above 95% indicates that the poll thread is basically spending all of its time

actually polling.

to evenly space out polling messages, it is unlikely to ever see Busy Time reach exactly 100%.

However, any percentage above 95% indicates that the poll thread is basically spending all of its time

actually polling

to evenly space out polling messages, it is unlikely to ever see Busy Time reach exactly 100%.

However, any percentage above 95% indicates that the poll thread is basically spending all of its time

actually polling.

Given a small amount of time is spent transitioning between poll buckets, and with the thread sleeping

to evenly space out polling messages, it is unlikely to ever see Busy Time reach exactly 100%.

However, any percentage above 95% indicates that the poll thread is basically spending all of its time

actually polling.

Includes (in parentheses) a ratio of “(time spent polling/total time since statistics were restarted)”.

Given a small amount of time is spent transitioning between poll buckets, and with the thread sleeping

to evenly space out polling messages, it is unlikely to ever see Busy Time reach exactly 100%.

However, any percentage above 95% indicates that the poll thread is basically spending all of its time

actually polling.