ModSim is described as '32 is a very simple but powerful application for simulating data from modbus slave devices. ModSim is an MDI application which allows you to define multiple blocks of data points which may then be accessed from a connected modbus master' and is an app in the development category. There are more than 10 alternatives to ModSim for a variety of platforms, including Windows, Linux, Web-based, Flathub and SaaS apps. The best ModSim alternative is ModPackQT, which is free. Other great apps like ModSim are CoreBus, ModScan, QModBus and Modbus Poll.