FairNET Broadcast

Operator Menu Location: Generic Hardware Operators Networking FairNET

Operator Bitmap:
 

Functional Description:
The FairNET Broadcast generic hardware operator provides access to a networking channel resource in the physical hardware. When the generic operator is linked to a specific networking hardware resource, it will broadcast a message over that channel resource using the FairNET protocol.

FairNET Broadcast operators encode their input signal x into a communication message that they broadcast over a controller network. All devices connected to the network will receive the broadcasted message. But, only those controllers with a receiver operator "tuned" to that broadcast will actually decode the message.

Design Pad supports two types of broadcast operators: analog and digital.
Analog FairNET Broadcast operators transmit encoded floating-point signals. They have two inputs---one analog and one digital. Analog input x is the signal that the operator is to broadcast. Digital input b disables (HIGH) or enables broadcasting (LOW). If the digital input is not connected, broadcasting is always enabled.
Analog broadcast operators use a 16-bit integer to encode the analog input signal. A 16-bit integer can assume distinct values (0-65535). The communication message m---the 16-bit integer that the analog broadcast operator transmits is determined from:

where is the minimum value that x is expected to assume and is the maximum value that x is expected to assume. The signal mappings and are properties of the broadcast operator.

Digital FairNET Broadcast operators transmit boolean signals. They have two digital inputs. Digital input x is the broadcast signal and digital input b is the disable pin. To minimize bandwidth utilization, the FairNET protocol packages multiple digital messages (bits) originating from the same device into a single message.

User-Defined Properties:
Signal Name. A string label that identifies the broadcast signal. It is used to associate this FairNET Broadcast operator in one schema with FairNET Receiver operator(s) in other schemas.

Initial Broadcast Value. The signal value transmitted initially.

Broadcast Priority. This parameter indicates if the network signal is critical or non-critical. Critical signals are deterministic; a FairNET network guarantees that consecutive critical broadcasts occur within a specified time interval (the critical broadcast interval is a property of the FairNET network that the operator is part of). Non-critical signals are non-deterministic; consecutive broadcasts generally occur within a specified time-interval but may occasionally take more time (the non-critical broadcast interval is a property of the hardware module that the operator is linked to).
0% Mapping. The lower limit of the x input signal range,
100% Mapping. The upper limit of the x input signal range, .

Display Enable Input. This property determines if the enable input pin b is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked).

Comments: None.

See Also: FairNET Receiver