LEDs and bulbs may be powered and controlled by the AUX function outputs of the decoder. In general it is recommended to use LEDs, as these have very long lives and do not generally get hot.

LEDs should always have their positive terminal connected via a resister to the decoder's common positive (blue), and their negative terminal to one of the AUX function outputs e.g. white, yellow, green, purple etc.

Configuration of what Function Key controls each AUX output is detailed in the section on Extended Function Mapping.

In addition, a variety of lighting effects can be applied individually to each AUX output, as detailed in CVs 154 to 161. In addition, dimming may be applied to one or more AUX outputs using CV 54 to choose the dimming level and CV57 to choose which AUX outputs to apply this dimming to. You cannot dim different AUX outputs by different amounts - they are either 100%, or they have the value in CV54 applied.