A point in a MicroSmart controller is receiving its input value from the global broadcast table and it's fluctuating every few seconds by 20 degrees.

Issue

A point in a MicroSmart controller is receiving its input value from the global broadcast table and it's fluctuating every few seconds by roughly 20 degrees.

Product Line

TAC I/A Series

Environment

DMS

Niagara R2

Niagara G3

Cause

Two MicroSmart points are broadcasting on the same global channel.  The two points can be from the same controller or from different controllers on the bus.  One is broadcasting a value around 50°F and the other around 70°F.  This is causing the 20 degree fluctuation every few seconds.

Resolution

The two points must be identified and then given unique broadcast channel numbers.  This will prevent the fluctuation.

The global table will identify one point but not the other one.  The process of manually checking each controller's global table and points database may be required.  The point configuration screen will identify the broadcast channel assigned.  Once the duplicate is found, assign it an unused channel number.