Modem Circuits - Electronics Tutorial and Schematics Here is the schematic diagram of the modem circuit. Power Line Modem Circuit for Home Automation Application - Imagine you have a master controller device that control other devices in your house, and you don’t need to install any additional wires to facilitate the data communication between the master controller and the controlled devices. 11.0 Wiring Diagrams and Schematics - DSLReports Home Modem Test at the INI (Indoor Network Interface) Below is a basic schematic for testing your modem at the INI (Indoor Network Interface). For detailed instructions please reference the INI Test FAQ. NOTE: If you live in a standard residential home please reference the NID Test FAQ and NID Test Schematic .