How do I set the LonWorks send and receive heartbeats settings for localLonDevice in an I/A Series R2 UNC station?
TAC I/A Series
I/A Series R2 UNC
There may be a need to change the settings for the LonWorks send and receive heartbeats settings in an I/A Series UNC station (for faster or slower updates).
To change the send heartbeat of the localLonDevice:
Go to the UNC station's lonLonDevice properties Config tab. The maxSendTime and minSendTime is the send heartbeat settings for the localLonDevice (LLD).
As per the Niagara LonWorks Integration Reference page 9-4 to 9-6 (which is installed together with the installation of I/A Series WorkPlace Pro software), maxSendTime and minSendTime are defined as follows.
maxSendTime: Specifies the maximum amount of time (in seconds) that the LLD waits to write an output value—if the value has not changed in this amount of time, the LLD will send it anyway. Maximum send time ensures that network variable updates are received by destination nodes (whether they change or not) within the limits set by that node's receive heartbeat limit.
minSendTime: Restricts the number of network variable updates placed on the wire. Regardless of the rate at which the network variable is updating, it will only be sent at this rate. This property prevents the network from being congested by values that are oscillating at an abnormal rate.
To change the receive heartbeat of the localLonDevice:
Go to the UNC station's lonLonDevice properties Config tab and expand the nvoStatusProps property. The Receive Heartbeat is used to ensure timely network variable updates are transmitted and received. If this property is set to zero, the local LON device does not expect periodic updates of its linked inputs - it simply waits until the value changes.