Bus Assignment
Replace specified bus elements
- Library:
Simulink / Signal Routing
HDL Coder / Signal Routing
Description
The Bus Assignment block assigns the values of a signal to bus elements. Use a Bus Assignment block to change bus element values without adding Bus Selector and Bus Creator blocks that select bus elements and reassemble them into a bus.
Connect the bus signal to the first input port. To other input ports, connect one or more signals whose values you want to assign to a bus element. Use the Block Parameters dialog box to specify the bus elements to be replaced. The block displays an assignment input port for each such element. For an example of a model that uses a Bus Assignment block, see Replace Signal Values of Bus Elements.
By default, Simulink® repairs broken selections in the Bus Assignment Block
Parameters dialog boxes that are due to upstream bus hierarchy changes. Simulink generates a warning to highlight that it modified the model. To prevent
Simulink from making these repairs automatically, in the Model Configuration Parameters > Diagnostics > Connectivity pane, set the Repair bus selections diagnostic to
Error without repair.
Limitations
When using arrays of buses with a Bus Assignment block, these limitations apply:
You can assign or replace a nested bus that is an array of buses. For a bus that is nested inside an array of buses, see Assign into Arrays of Buses.
To replace a signal in an array of buses, use a Selector block to select the index for the bus element that you want to use with the Bus Assignment block. Then, use that selected bus element with the Bus Assignment block.
Ports
Input
Output
Parameters
Signals in the bus — Bus element signals of input bus
list of signal names
List of the bus element signals of the input bus signal. An arrow next to a signal name indicates that the input signal is a bus. To display the signals in an input bus, click the arrow.
Click any item in the list to select it. To find the source of the selected signal, click Find. Simulink opens and highlights the system containing the signal source. To move the currently selected signal into the adjacent list of signals to be assigned values (see Signals that are being assigned below), click Select. To refresh the display to reflect modifications to the bus connected to the block, click Refresh.
Filter by name — Filter set of displayed signals
text
Specify a search term to use for filtering a long list of input signals.
Do not enclose the search term in quotation marks. The filter does a partial
string search. To access filtering options, including using a regular
expression for specifying the search term, click the 
button on the right of the Filter by
name edit box.
Enable regular expression — Filter set of displayed input signals
off (default) | on
Enable the use of MATLAB® regular expressions for filtering signal names. For
example, entering t$ in the Filter by
name edit box displays all signals whose names end with a
lowercase t (and their immediate parents). For details,
see Regular Expressions (MATLAB).
Dependencies
To access this parameter, click the button on the right of the Filter by
name edit box.
Show filtered results as a flat list — Filter set of displayed input signals
off (default) | on
By default, the list displays as a tree list of filtered signals, based on the search text in the Filter by name edit box. To use a flat list format that uses dot notation to reflect the hierarchy of bus signals, select this parameter.
Dependencies
To access this parameter, click the button on the right of the Filter by
name edit box
Signals that are being assigned — Names of bus elements to be assigned values
list of signal names
Names of bus elements to be assigned values. This block displays an assignment input port for each bus element in this list. The label of the corresponding input port contains the name of the element. You can order the signals by using the Up, Down, or Remove buttons. Port connectivity is maintained when you change the signal order.
If an input bus no longer contains a bus element, three question marks
(???) appear before the name of that bus element. The
bus has changed since the last time you refreshed the Bus
Assignment block input and bus element assignment lists. To
address this issue, either modify the bus to include a signal of the
specified name or remove the name from the list of bus elements designated
to be assigned values.
Programmatic Use
Block Parameter:
OutputSignals |
| Type: character vector |
Values:
'signal1'|'signal2' |
| Default: none |
Model Examples
Block Characteristics
Data Types |
|
Direct Feedthrough |
|
Multidimensional Signals |
|
Variable-Size Signals |
|
Zero-Crossing Detection |
|