It is sometimes useful to have signals that can apply to all models. These may be signals from devices, or from other systems that are presented as if they were signals from a device. Analytics Builder thus supports devices that are referred to as broadcast devices and signals from these devices are available to all models across all devices.

Broadcast devices can be used as inputs in any model, together with either specific device inputs or device group inputs. The diagram below illustrates how a broadcast device applies to all devices within a device group. It is possible to combine signals from devices in a device group with signals from a broadcast device by providing them as different inputs into a processing block such as the Expression block.

Unlike other devices, a broadcast device can only be used for synchronous output of a model that only consumes data from broadcast devices. Broadcast output of the asynchronous type can be generated by a model consuming non-broadcast inputs.

It is also not possible to connect models together using synchronous data from a broadcast device output (that is, no model may use a measurement from a broadcast device that is the output of a different model). Models can be connected together using asynchronous outputs from a broadcast device (that is, models may use an operation from a broadcast device that is the output of a different model).

Broadcast devices are identified by the presence of a property on the device object in the inventory for that device; the presence of either the pas_broadcastDevice or c8y_Kpi property. Thus, whether a device is considered a broadcast device or not is global for that device across all models. It is not permitted to use a device group that contains a broadcast device. c8y_Kpi objects are typically used with the KPI block. Thus, it is possible to use a KPI object to compare measurements from a group of devices - one KPI object is used for all devices in the group.