How often is a SNVT in a Lon device polled if an alarm monitors that variable?

Issue

How often is a SNVT in a Lon device polled if an StruxureWare Building Operation alarm monitors that variable? What happens if a shunt variable is used - is the polling rate still the same?

Product Line

SmartStruxure Solution

Environment

Lon Device

StruxureWare Building Operation

Cause

Alarms are to monitor SNVTs in a Lon device put polling may overload the network.

Resolution

An alarm monitoring a SNVT will be polled every 100 ms. If a shunt variable is then activated the pollrate will drop to 5 000 000 ms. This can be seen in the variable manager:

  • Go to Server 1/System/Modules/RuntimeDBManager/VariableManager/Variables in Workstation
  • Locate the variable in question and ensure that the Imposed Pollrate column is shown.