Clocks in a LON system are integrated in the same network that is used for e.g. illumination control and alarm control in a building. This means that all the ingoing units in the network are connected on the same cable pair.

Westerstrand equipment for LON-systems comprises time bases (master clocks or time centrals) analogue clocks and digital clocks. The master clock WDP-LON is a time base for the entire LonWork-net and provides the net with correct time in selectable intervals.

The clocks include automatic detection of the hands positioning and several control functions to guarantee safe and accurate operation. In case data messages fail to be delivered the clock starts operating independently from the system. Clocks are then controlled by a built in quartz crystal time base. The time period accepted for independent operation is programmable. When the configured time is out, the clock sets position of the hands at 12:00 and stops.