When must the ditch lights be on?

I'm not looking to get anyone in trouble, but lately I've noticed the ditch lights on the P32ACDM turned off. When must they be on, when the loco is leading the train? I noticed this while waiting for the train at Bedford Hills, as a northbound express had its ditch lights alternating as it passed the station, other times the lights were off. I caught this P32ACDM (#210 leading to Poughkeepsie),just north of Croton Harmon while waiting at Senasqua Road. http://naphotos.nerail.org/showpic/?pho ... &bydate%3A[/img][/url]

The Ditch lights need to be on all times on non automatic equipment like M1/M2/M3/etc.
the Genesis(p32acdm) has a automatic system were ditchlights come on flashing whenever the engineer uses the horn, like crossings/ platforms/ people on or about track etc.
There is a Bright plus Ditchlight setting on Genesis but its optional when to use this. The flashing will still work if the switch is in all lights on mode.

Ditch lights are also not required while a train is in the yard limits.

Linking the ditch lights to the horn activation was not something I would have thought of, but it does make sense. One less thing for the engineer to remember. Thanks