The USB DMX interface uses a FT245BM USB device from FTDI. They supply drivers for most O/S, and you should start by visting the driver download page, and installing the driver for your O/S.

Communication with the USB DMX interface is asynchronous, that is you do not need to wait for a command response before sending the next command, and an interface generated response (such as a change to a DMX channel value) may be received before the response to your command. However command responses will always be in the order the commands were sent to the interface.

The protocol has been designed to be as efficient (fast) as possible, this means that it is based around unsigned bytes and not ascii characters, therefore a lot less bytes need to be sent. For example to set a DMX channel value only 3 bytes need to be sent to the USB DMX interface.

The full protocol including commands and responses is available for download as a PDF document. If you have any problems understanding the protocol then please email me and I will add more explanation to the document.

The dmxtester application source is a project builder project including all source files for a simple application to test every feature of the USB DMX interface. Further details of the usbdmxtester application can be found in the Software section.

protocol.pdf (24KB) (Updated 25/02/2007)

usbdmxtester_source.dmg (144KB)