# Vehicle Spy Tour 4: Node/Vehicle Simulation

![](/files/6ZOAmRqlClaGiV2Yf2S8)

Node/Vehicle simulation is simulating an electronic module or car on a network. Many times a development engineer needs to develop the network software interface but has no network or car to talk to. The modules intended to communicate with may not be available at all. Using Vehicle Spy's simulation features, engineers can perform their test without those modules.

Responding to a message received is a very common task in node simulation. This means that when a module receives a specific message, it should respond with a message within a certain period of time. This response can be a function of the message received. For example, the value responded with can be the same as received with a few bits of the message received changed.

The Vehicle Spy playback feature allows vehicle traffic to be simulated. For instance, data can be collected in the car and stored. Later, this same data can be played back to a module. Captured problems can be repeated and tests can be accomplished.

Vehicle Spy is also able to generate messages periodically or when specified events occur, two more features often useful for Node/Vehicle Simulation.

[**Introduction**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction.md) **-** [**Overview**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction/vehicle-spy-overview.md) **-** [**Applications Tour**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction/vehicle-spy-overview/vehicle-spy-tour/vehicle-spy-tour-1-bus-monitor.md) **-** [**Users**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction/other-vehicle-spy-users.md) **-** [**Specifications**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction/vehicle-spy-specifications.md) **-** [**Required Hardware**](/vspy-3-documentation/3.9.17/vehicle-spy-introduction/vehicle-spy-required-hardware-pc-system-requirements.md) **-** [**Website**](https://intrepidcs.com/products/software/vehicle-spy/vspy-float/)


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