Null modem - Wikipedia OverviewOriginsCables and adaptersApplicationsTypes of null modemNull modem is a communication method to directly connect two DTEs using an RS-232 serial cable. The name stems from the historical use of RS-232 cables to connect two teleprinter devices or two modems in order to communicate with one another; null modem communication refers to using a crossed-over RS-232 cable to connect the teleprinters directly to one another without the modems. It is also used to serially connect a computer to a printer, since both are DTE, and is known as a Printer Cable. ThSee more on enpedia · Text under CC-BY-SA license 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. Teardown: Inside a cable modem It is a single-chip cable modem made by Broadcom. A lot of cable boxes use it. This particular chip is the BCM3348. It isn’t the most up-to-date version of Broadcom’s single-chip cable modem offerings, but the architecture of the hardware on this board isn’t much different from what would surround the latest and greatest versions.