Compare To Constant (Simulink Reference)

Determine how a signal compares to the specified constant

Library

Logic and Bit Operations

Description

The Compare To Constant block compares an input signal to a constant. Specify the constant in the Constant value parameter. Specify how the input is compared to the constant value with the Operator parameter. The Operator parameter can have the following values:

== -- Determine whether the input is equal to the specified constant.
~= -- Determine whether the input is not equal to the specified constant.
< -- Determine whether the input is less than the specified constant.
<= -- Determine whether the input is less than or equal to the specified constant.
> -- Determine whether the input is greater than the specified constant.
>= -- Determine whether the input is greater than or equal to the specified constant.

The output is 0 if the comparison is false, and 1 if it is true.

Data Type Support

The Compare To Constant block accepts inputs of any data type supported by Simulink, including fixed-point data types. The block output is uint8 or Boolean as specified by the Output data type mode parameter.

For a discussion on the data types supported by Simulink, refer to Data Types Supported by Simulink in the Using Simulink documentation.

Parameters and Dialog Box

Operator: Specify how the input is compared to the constant value, as discussed in Description.
Constant value: Specify the constant value to which the input is compared.
Output data type mode: Specify the data type of the output, uint8 or Boolean.
Enable zero crossing detection: Select to enable zero-crossing detection. For more information, see Zero Crossing Detection in the Using Simulink documentation.

Characteristics

Direct Feedthrough
Yes

Scalar Expansion
Yes

Zero Crossing
Yes, if enabled.

Direct Feedthrough	Yes
Scalar Expansion	Yes
Zero Crossing	Yes, if enabled.

See Also

Compare To Zero

Combinatorial Logic Compare To Zero