What type of communication does USB use for connecting a programming device to a PLC controller module?

USB (Universal Serial Bus) technology is based on a serial communication method. In this type of connection, data is transmitted one bit at a time over a single channel, which is characteristic of serial communication. This allows for a more straightforward and efficient connection between the programming device and the PLC (Programmable Logic Controller) module.

In the context of a PLC, utilizing a USB connection helps facilitate programming, configuration, and data transfer between the controller and a computer or programming device. USB's serial nature allows for reliable data transmission with lower overhead, making it a common choice in many devices, including PLCs, where robustness and ease of use are prioritized.

The other communication types—such as Ethernet (which is used for networking and higher data transfer rates), wireless (which lacks the physical connection standard required for most PLCs in industrial settings), and parallel (which transmits multiple bits simultaneously but is generally less common in modern interfaces like USB)—do not accurately describe the method used by USB for connecting programming devices to PLC controller modules.