This USB to I2C module provides a complete interface between your PC and the I2C bus. The module is self powered from the USB cable and can supply up to 70 milliamps at 5V for external circuitry from a standard 100 milliamp USB port. The module is an I2C master only, not a slave.
Reading and writing an I2C packet generally follows a specific command structure. Often, one will send a structured packet to the virtual serial port with a I2C-USB command, followed by the I2C device address with address registers and informational bytes. Details and examples on usage can be found on the Technical Documentation page.