The XLR or Cannon is a type of connector that usually connect balanced lines. In fact, it is more balanced connector used for professional audio applications, and is also the standard connector used in entertainment lighting equipment to transmit the digital control signal "DMX". His nickname cannon, for which he is best known in Spain is that the first to be used in this country, were made by theITT/CANNON brand, and carried "cannon" stamped on the chassis. It has three pin plug and European standard for audio signals is as follows: for the earth or mesh. for one-phase signal, known as a living or hot to the back or push-pull signal, known as return or cold. It is available in version 3-pin and 5-pin.