Hi, I apologize if this has been asked previously. As an example I have two F-7a's Mu'ed back to back. Engine #111 is the lead unit with #120 in trail. I have re-programmed CV-29 to allow #120 to run reverse when operating in trail. Headlight function is normal with #111 (on in forward, off in reverse). How can I program this or any other back to back set so that the headlight comes on the rear unit when I reverse direction? How can this be accomplished with hood units so the rear headlights of the lead units do not come when direction is reversed but the trailing unit headlight DOES operate. I have heard this is not complicated but I am fairly new to DCC. Thanks for any help. A F Niederer Rock Island Modeler from NW Indiana
No need to apologise for asking a question, AFN. I think you're talking consisting here and I've been looking at the same thing. This is one slant - from what I have read, you can set CV33 and CV34 for each loco according to the direction they are consisted, given 111 is lead facing forward and 120 is trailing facing backward but considered forward in the consist. Therefore, I believe you will need to set CV33=1 and CV34=0 in 111 and CV33=0 and CV34=1 on 120. That way in forward 111's headlight will be alight but no lights in 120 and vice versa in reverse. If any additional units are placed in between these then CV33 and 34 needs to be 0 so no lights show. Reading between the lines, it seems some DCC systems take care of this for you, others don't and have to be set manually when consisting. This is the latest site I have found covering this - http://www.members.optusnet.com.au/nswmn2/DCC.htm#ConHL A question - do you have rear lights on your F-units? Mine have both up front being twin headlights with the top being a Gyralight and the lower a headlight in forward.
What Gats said will probably work, but you need to check your decoders and see if they use CV 33 and 34 for lighting control because not all decoders do. There are three types of consisting and light control varies depending on the type of consisting you use: 1. Basic consisting - This is where you progarm the locomotives to the same address. When doing this you have to configure the lighting the way Gats said. 2. Command station assisted consisting (goes by diffirent names, Digitrax calls it Universal Consisting) - When using this method, the command station keeps track of the engines in the consist and you can address the engines individually to control their lights. 3. Decoder assisted consisting - Not all decoders support this, but most of the newer ones do. This uses the consist address programmed into CV 19. To do this with the consist you described, first re-program CV 29 in the trailing unit to the original value. Then pick a consist address less than 128. Program this number into CV 19 on the lead loco. Program this number + 128 into CV 19 on the trailing loco(the + 128 causes the loco to run in reverse). Then program CV 22 to 1 in both loco's so that only the front headlight will respond to the consist address. If the rear loco was facing forward, you could program CV 22 with 2 and only it's rear headlight would respond, and if you have loco's in the middle, program CV 22 to 0 and none of their headlights will respond. One advantage to using this type of consisting is that if you want to run the engines individually, program CV 19 with 0 and the headlights go back to working normally and the engine reponds to it's normal address, program CV 19 with the consist address and the engines respond to the consist address and the headlights work as before. Remember to check your decoder manuals because CV19 and CV 22 (as well as CV 33 and 34) are optional, they are not required for a decoder to be NMRA compliant.
Thanks Gats and CSX Robert. As soon as I get a chance I will try the options listed and report back. Gats, RI freight F's had only the single headlight casting in the nose. Their passenger E's and F's had both the upper gyralight and lower standard headlight. I have several of the older P2K E-units that I have custom painted for the Rock Island but have not tackled installing decoders in them as they must be hard wired. There are some internal modifications necessary to do this I believe. The only rear light would have been a back up light offset to the right on the rear of the unit.(I think) I have seen pictures of some F's that had a larger light mounted on the roof above the rear door. I cannot remember what road might have had this feature. Again, thanks for the reply
Thanks for the advice!! I did manage to get my back to back set of F's to cooperate with the headlight issue. I also tried to program sets of GP-40's. It may take a little trial and error with different sets of power since some of my engines are factory ready and some of them I have installed decoders. Again, thanks A F Niederer
