inputs

Define component inputs, that is, Physical Signal input ports of block

Syntax

inputs in1 = { value , 'unit' }; end  
inputs in1; end

Description

inputs begins a component inputs definition block, which is terminated by an end keyword. This block contains declarations for component inputs. Inputs will appear as Physical Signal input ports in the block diagram when the component file is brought into a Simscape™ model.

Each input can be defined as:

  • A value with unit, where value can be a scalar, vector, or matrix. For a vector or a matrix, all signals have the same unit.

  • An untyped identifier, to facilitate unit propagation.

Specifying an optional comment lets you control the port label and location in the block icon.

The following syntax declares a component input, in1, as a value with unit. value is the initial value. unit is a valid unit string, defined in the unit registry.

inputs
    in1 = { value , 'unit' };
end

If you declare an input without a value and unit, as an untyped identifier, it propagates the signal type (size and unit) based on the component connections in the model. Use the following syntax to declare a component input, in1, as an untyped identifier.

inputs
    in1;
end

Note

During ssc_build validation, or when an input is unconnected in a model, untyped inputs receive the type of unitless scalar, that is, {0, '1'}. Therefore, a component with an untyped input must support the type of the input being resolved to unitless scalar.

You can specify the input port label and location, the way you want it to appear in the block diagram, as a comment:

inputs
    in1 = { value , 'unit' };  % label:location
end

where label is a string corresponding to the input port name in the block diagram, location is one of the following strings: left, right, top, bottom.

Examples

The following example declares an input port s, with a default value of 1 Pa, specifying the control port of a hydraulic pressure source. In the block diagram, this port will be named Pressure and will be located on the top side of the block icon.

inputs
    s = { 1, 'Pa' };   % Pressure:top
end

The next example declares an input port I as a row vector of electrical currents. The three signals have a default value of 1 A. The signal initial values may be different, but the unit has to be the same.

 inputs
   I = { [1 1 1], 'A'}; 
 end

You can also reference component parameters in input declarations. For example, you can control the signal size by using a block parameter:

component MyTransformer
     parameters 
         N = 3; % Number of windings
     end
     inputs
         I = {zeros(N, 1), 'A'}; 
     end
     ....
 end

The following example declares an input port I as an untyped identifier. The unit and size of the input physical signal at port I are propagated from the connected output port.

 inputs
   I;
 end
 

Introduced in R2008b