Ditch Lights
Home Up Marker LED Sources Ditch Lights Effects

 

Desired Ditch Light Operation

Head light Ditch lights Normal use
off off Not in use or not lead unit
on off Switching or meeting vehicle traffic
dim off Meet opposing train
on on Normal operation
on flashing Grade crossing (not all railorads do this)

Also I want the rear headlight to be independenty controled with independent dimming if possable.

Here are the GECOR headlight rules:

5.9 Headlight Display
Turn the headlight on bright to the front of every train, except when the light must be dimmed as outlined in Rule 5.9.1 (Dimming Headlight) or turned off as outlined in Rule 5.9.2 (Headlight Off).

5.9.1 Dimming Headlight
Except when the engine is approaching and passing over a public crossing at grade, dim the headlight during any of the following conditions:
1. At stations and yards where switching is being done.
2. When stopped close behind a train.
3. When stopped on the main track waiting for an approaching train. However, when stopped in block system limits, turn the headlight off at the radio request of the crew of an approaching train, until the head end of the train passes.
4. When approaching and passing the head end of a train on the adjacent track.
5. At other times to permit passing of hand signals or when the safety of employees requires.
6. When left unattended on a main track in non-signaled territory.

5.9.2 Headlight Off
Turn the headlight off under either of the following conditions:
1. The train is stopped clear of the main track.
2. The train is left unattended on the main track in block system limits.

5.9.4 Displaying Headlights Front and Rear
When engines are moving, crew members must turn on the headlight to the front and rear, but may dim or extinguish it on the end coupled to cars.

5.9.5 Displaying Ditch Lights
Display ditch lights, if equipped, to the front of the train when headlight is on bright.
Locomotives must not be operated as the lead unit out of a train’s initial terminal unless both ditch lights are operating. However, if no units are equipped with ditch lights, do not exceed 20 MPH over public crossings until occupied.

Not all CVs shown, CVs not directly need for ditch light/dimming operation not shown.   Other decoder from the same manufacturer should have same settings if they support the lighting effects.  There may be other ways to achieve the same results (i.e. on decoders that support function remaping, other functions could be used for a particular feature with corresponding CV changes).

Digitrax FX

Dimming not available a the same time as ditch lights if you want independent lighting.  All FX class decoders, tested on DH142.  Note the ditchlight logic is hard coded to F0, if you want to have the headlight on without the ditchlight on, then you need to put the headlight on different function.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Ditch light 1 49 106 6A right ditch light
yellow Rear light 50 0 00 no effect
green Head light 51 0 00 no effect
purple Ditch light 2 52 107 6B left ditch light
  61 1 01 independent lights

Function Mapping

Head light Ditch lights Functions
off off none
on off F1
dim off N/A
on on F0  F1
on flashing F0  F1  F2

Rear light on F4, no dimming

Digitrax FX3

Dimming not available a the same time as ditch lights if you want independent lighting.  All four or more function FX3 class decoders, tested on DH163D.  Note the ditchlight logic is hard coded to F0, if you want to have the headlight on without the ditchlights on, then you need to map the headlight on different function.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Head light 49 0 00 no effect
yellow Rear light 50 0 00 no effect
green Ditch light 1 51 106 6A right ditch light
purple Ditch light 2 52 107 6B left ditch light
  33 0 00 F0f no output (hard coded to effect)
  34 0 00 F0r no output (hard coded to effect)
  35 1 01 headlight mapped to F1
  36 0 00 F2 no output (hard coded to effect)
  37 2 02 rear light mapped to F3

Function Mapping

Head light Ditch lights Functions
off off none
on off F1
dim off N/A
on on F0  F1
on flashing F0  F1  F2

Rear light on F3, no dimming

Lenz XF/XS

All four (or more) function XF class decoders.  I only had a LE102XF available to test, this decoder only has three outputs, but it has all the programming stuff and the three functions it does have worked as expected. Table is  for earlier versions, later versions of Lenz decoders changed how CV54 & 55 worked when CV53 is setup for ditch light operation.  Early versions hard coded F2 to trigger the alternating flashing and both CV54 & 55 had to be programmed to the same F number.  Later versions, CV54 specifies which F number turns on/off the ditch lights and CV55 specifies which F number triggers the alternating flashing.  Early version used in table below.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Head light 51 15 0F Independent lights and dimming
yellow Rear light 52 64 40 Dimming value
green Ditch light 1 53 4 04 Output C & D to ditch light effect
purple Ditch light 2 54 4 04 Set output C to F3
  55 4 04 set output D to F3

Function Mapping

Head light Ditch lights Functions
off off none
on off F0
dim off F0  F4
on on F0  F3
on flashing F0  F3  F2

Rear light is on F1, with F4 dimming.

NCE SR

All four (or more) function SR decoders.  Tested on P2K-SR.  Note the ditchlight logic is hard coded to F0, if you want to have the headlight on without the ditchlight on, then you need to map the headlight on different function, not F0.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white (1) Head light 120 32 20 F4 Dimming
yellow (2) Rear light 121 36 24 F8 Dimming
green (3) Ditch light 1 122 60 3C Type 1 right ditch light
purple (4) Ditch light 2 123 56 38 Type 1 left ditch light
  33 0 00 F0(f) to no output (ditch on)
34 0 00 F0(r) to no output (ditch on)
35 1 01 F1 to output 1
36 12 0C F2 to outputs 3 &4 (flash)
37 2 02 F3 to output 2
38 0 00 F4 to no output (used for dim)

Function Mapping

Head light Ditch lights Functions
off off none
on off F1
dim off F1  F4
on on F1  F0
on flashing F1  F0  F2

Rear light is on F3, with F8 dimming.

Soundtraxx Diesel DSD

The LC series do not have four functions and the DSX does not have any, so this work only for the original DSD with diesel sounds.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Head light 49 1 01 Rule 17 dimmable light
yellow Rear light 50 1 01 Rule 17 dimmable light
green Ditch light 1 51 41 29 Type 1 ditch, grade x'ing, phase A
purple Ditch light 2 52 57 39 Type 1 ditch, grade x'ing, phase B
  33 1 01 FL(f) to output HL, head light
34 1 01 FL(r) to output HL, head light
35 2 02 F1 to BL, backup light
36 8 08 F2 to horn and flash ditch lights
40 24 18 F6 to F5 & F6 outputs
41 16 10 F7 to dim headlight

Function Mapping

Head light Ditch lights Functions
off off none
on off F0
dim off F0  F7
on on F0  F6
on flashing F0  F6  F2

Rear light is on F1, with F7 dimming.

Train Control Systems

All four (or more) function decoders.  Tested on TH-141P version 9.  TCS does frequent software changes, this may effect programming.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Head light 49 40 28 Rule 17
yellow Rear light 50 40 28 Rule 17
green Ditch light 1 51 42 2A Ditch light A
purple Ditch light 2 52 43 2B Ditch light B
  61 1 01 Independent lights

Function Mapping

Head light Ditch lights Functions
off off none
on off F0
dim off F0  F5  and
F0 + stopped
on on F0  F1  F3
on flashing F0  F1  F3  F2

Rear light is on F1, with F4 dimming.
Note:  F5 (dimming) will also cause the ditch lights to flash if they are on (which is OK as you should not need dimmed headlight with ditch lights on anyway).  If the head light or rear light are on and the loco is at speed step 0 ( stop) the lights will be dimmed automatically.

Zimo

All Model 2000 four (or more) function decoders with software version (CV7) 11 or later.  Tested on MX61/N.

Physical Connections and CVs

Wire Use CV Dec Hex Description
white Head light 125 0 00 Standard on/off
yellow Rear light 126 0 00 Standard on/off
green Ditch light 1 127 33 21 Ditch light type 1 right
brown Ditch light 2 128 37 25 Ditch light type 2 left
  33 1 01 F0 forward controls white
34 1 01 F0 reverse controls white
35 2 02 F1 controls yellow
36 0 00 F2 controls none (ditch flash)
37 3 03 F3 controls green & brown
114 0 00 full time dimming off
119 1 01 F6 dims white
120 2 02 F7 dims yellow

Function Mapping

Head light Ditch lights Functions
off off none
on off F0
dim off F0  F6
on on F0  F3
on flashing F0  F3  F2

Rear light is on F1, with F7 dimming.