A DMX sniffer for USB is a device that allows you to capture and analyze DMX data. DMX (Digital Multiplex) is a protocol used to control lighting and other stage equipment. A DMX sniffer can be used to troubleshoot problems with DMX systems, or to simply monitor and analyze DMX data.
DMX sniffers are available in both hardware and software form. Hardware sniffers are typically more expensive, but they offer more features and capabilities. Software sniffers are less expensive, but they may not be as reliable or accurate as hardware sniffers.