Different direction?


A

Alan Curtis

Member
I just installed a decoder in a Kato Alco Rsc2 and a Atlas Alco C425. Both have 8 pin sockets for the plug in decoders I used (non-sound). HO scale.

Strange thing is, although they are plug in type, the locomotives go in opposite directions! I would have expected all dcc ready locos to operate the same way?
 
I have a few locos that ran opposite of the others.
There is a CV that sets normal direction of travel, can't remember which one but it should be in the instructions.
 
This is not an uncommon occurrence with DCC apparently. It is easily corrected when setting up the loco with your cab. Don't know how it is with other brands, but with my NCE, when setting basic decoder configuration (CV29), the direction bit-normal or reverse is the first option. Press Enter for normal (forward) or 1 for reverse. Could be different for other systems. Out of the 6 locos I've set up so far only 1 has been the wrong way round. The ability to change this setting at will is necessary for tail to tail consisting in order to change the trailing engines direction, unlike DC where it would obey the track current's direction.
 
Last edited by a moderator:
Gee, is that the reason the Burlington Route ran many of their E-units "elephant style"? They couldn't find the right CV? ;)
 
Did it actually run the wrong way ? The C425 is obvious which way is forward, but for the RSC2, different railroads may have had different ideas as to which way they were labelled as forward. There should be a little "F" on the side sill to indicate which way was forward.

Mark.
 
Alan Curtis said:
Yes, but when both locos were placed on the track, regardless of which is Front, when run went in different directions.

BTW, the Andersley Western runs Alcos RS's long hood forward ;)

Alan
www.andersley.co.uk
Click to expand...

Maybe I'm not quite following .... you say they went in different directions, you mean when running them together on the same address ? If you turned one around, they would both run in the same direction. With DCC, front is always forward regardless which way it's facing on the track, unlike DC. That's why I asked if the engine(s) were moving forward based on the "F" displayed on the side sill or not.

Mark.
 
In DC, the direction of travel is determined by which rail is positive and which is negative and the loco motors react accordingly. If I place locos together facing the same direction with the direction switch facing in their forward direction, they will both travel in that direction. If I turn one loco around in consist, it will still travel in the direction that the direction switch is pointing.

In DCC you have to instruct each loco via each ones decoder which way you want it to go. This is why when setting up a consist (where the last loco is reversed) you have to "tell" it to travel in reverse while it is part of that consist address.
 
I realise that if a locomotive is turned around it will still run in the same direction according to track direction. But if say, left to right is forward on the controller, all locomotives must move left to right at the forward setting.

This is why I needed to change the CV29 setting to make the particular locomotive behave as the others.

Alan
www.andersley.co.uk
 
tootnkumin said:
In DC, the direction of travel is determined by which rail is positive and which is negative and the loco motors react accordingly. If I place locos together facing the same direction with the direction switch facing in their forward direction, they will both travel in that direction. If I turn one loco around in consist, it will still travel in the direction that the direction switch is pointing.

In DCC you have to instruct each loco via each ones decoder which way you want it to go. This is why when setting up a consist (where the last loco is reversed) you have to "tell" it to travel in reverse while it is part of that consist address.
Click to expand...

I know that. What I was trying to understand from Alan was how he determined they were "backwards". Two DCC engines with the front facing away from each other WILL run in opposite directions .... turn one engine around and they both run in the SAME direction. I was just curious regarding the RSC2 if when in forward, it was moving in the direction indicated by the "F" on the side sill or not. Depending on the railroad, either the long hood or the short hood could be considered "forward", just like numerous other engines / railroads. NS considered the long hood forward on most all their diesels for many years, and the DCC wiring from the factory for NS engines was configured as such.

All I'm saying is that Alan's engine may not necessarily be running "backwards" based on its proto-type.

Mark.
 
Alan Curtis said:
I realise that if a locomotive is turned around it will still run in the same direction according to track direction. But if say, left to right is forward on the controller, all locomotives must move left to right at the forward setting.

This is why I needed to change the CV29 setting to make the particular locomotive behave as the others.

Alan
www.andersley.co.uk
Click to expand...

Not with DCC. There is no "track direction" with DCC. If you are running left to right in forward. then pick that engine up and turn it around, you would then be running forward right to left without doing anything on your throttle.

Direction.JPG

Unless this is just your personal preference in that left to right is forward .... so what do you do if your engine is FACING to the left ? To run the engine in reverse, you press forward ? Sounds awfully confusing to me ....

Example using this picture of yours. In the picture, the UP RSC-2 should be moving to the right when in forward. The C-425 should be moving to the left when in forward ....

gallery001H.jpg

Mark.
 
Last edited by a moderator:
Hmmm... will have a play with them tomorrow. I guess it is because I have been running European trains for so long, and they have cabs at both ends, so front and back are not so important. I just used to look which end had the headlights on to see which way it would go!

Just started using US locos on DCC, so guess I have to think differently. Several more locos to fit with decoders, so will pay attention when doing so. Thanks for the input :)

Alan
www.andersley.co.uk
 
So long as the direction CV's are set to the direction you want each to run as forward in each loco, that is the way each will run. That may mean, that in the case of the RSC-2, that's it's CV is set to reverse. It will then respond to a "Forward" command from your cab by running long hood forward, if previously it was running short hood forward. The decoder really doesn't care which way forward or reverse is so long as we the operator have set which way we want it to be.
 
As far as those prototype double ended locos, they would have a mirror set of controls in each cab and I guess when the engineer sits in his seat and activates them, then as far as the mechanicals/control systems are concerned that cab is now the front. Which basically is all we do when we change CV29 from "normal" to "not normal" (my words) by choosing the alternative command indicated in your DCC system's manual. In the case of NCE you press button #1. Just don't forget to exit programming mode to have the decoder action the command.
 
You must log in or register to reply here.



Back
Top