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Ground unconnected input port

  • Library:
  • Simulink / Commonly Used Blocks

    Simulink / Sources

    HDL Coder / Sources


The Ground block connects to blocks whose input ports do not connect to other blocks. If you run a simulation with blocks that have unconnected input ports, Simulink® issues warnings. Using a Ground block to ground those unconnected blocks can prevent these warnings.

Working with Fixed-Point Data Types

When working with fixed-point data types, there may be instances where the fixed-point data type cannot represent zero exactly. In these cases, the Ground block outputs a nonzero value that is the closest possible value to zero. This behavior applies only to fixed-point data types with nonzero bias. These expressions are examples of fixed-point data types that cannot represent zero:

  • fixdt(0, 8, 1, 1) — an unsigned 8-bit type with slope of 1 and bias of 1

  • fixdt(1, 8, 6, 3) — a signed 8-bit type with slope of 6 and bias of 3

Working with Enumerated Data Types

When working with enumerated data types, the Ground block outputs the default value of the enumeration. This behavior applies whether:

  • The enumeration can represent zero

  • The default value of the enumeration is zero

If the enumerated type does not have a default value, the Ground block outputs the first enumeration value in the type definition.



expand all

The Ground block outputs a scalar signal with zero value, and the same data type as the port to which it connects.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean | fixed point | enumerated | bus

Block Characteristics

Data Types

Boolean | bus | double | enumerated | fixed point | integer | single | string

Direct Feedthrough


Multidimensional Signals


Variable-Size Signals


Zero-Crossing Detection


Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion
Convert floating-point algorithms to fixed point using Fixed-Point Designer™.

Introduced before R2006a