# VisSim/Block Reference

The Blocks menu lists the standard blocks provided with VisSim. When you click on the Blocks menu, most of the items that appear have a filled triangle (s) next to them. These items are block categories. Click on a block category and a cascading menu appears listing the additional blocks.

To make it easier to find blocks in this section, they are presented in alphabetical order, regardless of their block category. For most blocks, a mathematical function is included. The following table translates the symbols that may appear in the function:

Symbol |
What It Represents |

A | Amplitude |

e | Naperian constant |

dt | Derivative with respect to time |

lb | Lower bound |

mod | Modulus |

s | Laplacian operator |

t | Time |

ub | Upper bound |

ω | Frequency |

x | Input signal |

y | Output signal |

Input signals are represented as x1, x2, …xn where x1 represents the topmost signal entering the block. When n is omitted, x1 is assumed.

Output signals are represented as y1, y2, …yn, where y1 represents the topmost signal exiting the block. When n is omitted, y1 is assumed.