DMX Terminator connects to the termination of DMX devices to improve DMX signal reliability and prevent instability caused by signal reflection. Built-in LED lamp makes it easy to check the wrong connections such as unconnected, short circuit, reverse phase, etc. [Line Check Feature] Position: 3 - DMX + 2 - DMX - Red and Green lights are on simultaneously: PASS LED OFF: There may be faults such as disconnection, unconnected, etc. Only 1 Red OR Green Light: The pin wire of the DMX cable may be reverse phase.