Multifunction Decoder Programming Lock
Summary: Multifunction Decoder Programming Lock is a technique to lock multifunction decoders to prevent accidental programming or to enable programming two decoders in the same locomotive separately which share the same address. This allows one decoder to be locked, defeating the ability to program it, while allowing the other to be programmed. This feature can also be used to prevent accidental programming of a multifunction decoder. This feature uses CVs 15 and 16.
Multifunction Decoder Programming Lock is an optional feature, used when a multifunction decoder was installed in a locomotive and the modeller desired more functions than it supported. An additional decoder, such as a sound or function decoder sharing the same address, could be added and programmed independently. In operation all the decoders would respond to the same address. Today it would be rare to see such an arrangement, as multifunction decoders support a wide range of functions and sound effects. It could be used today with multiple function decoders installed for lighting or other effects in rolling stock, enabling control with one address of multiple decoders.
Another application is to prevent the accidental altering of the CVs in a multifunction decoder by an operator, such as adding or deleting a consist address.
For more information see the Decoder Programming Lock page.