The Update Interval attribute (Figure 1) is provided for every LonWorks output point object. This attribute enables a recurring heartbeat message from the network engine to controllers that require periodic contact. If a heartbeat message is not present, some LonWorks devices revert to local control.
Update Interval takes an integer value in seconds. The default is 0 seconds, which disables the heartbeat. The network engine can issue one heartbeat per second (maximum).
Once you enable the Update Interval, you must activate it by commanding the point to a different value or state, restarting the network engine, or taking the LonWorks device offline temporarily. You should also make sure the point is set for Auto Restore by assigning a value of True. Auto Restore restores the last command on the field device when the point returns from an offline condition, or when it is first starting up.
