Dual decoder help required please?

[Deleted]

Guys I'm relatively new to DCC in so much as I only really discovered it a few years ago and I have some questions.

I intend to have a roster of 5 or 6 loco's, which, initially I will add a motor decoder to to get myself DCC'd up. Later on I would like to add Soundtraxx Tsunami decoders to all of my locomotives (bar one Atlas D8-40CW). Being an NS modeller I would like front and rear ditch lights that flash alternatively when the horn sounds. I have read about multiple decoders used where you need extra lighting functions as I will and so I am researching my options.

Basically does anybody know if it is ok to use a Tsunami sound chip just for sound and lighting functions and use a different decoder for motor and other lighting functions?

[navy4422]

I believe the set ups I have seen would use the tsunami by its self and a chip that does the ditch lights(not a decoder) I am interested in doing a similar thing on my Sd70 Mac so I'll do a little more research

[lyled1117]

Absolutely possible and doable. However, I would recommend using the Tsunami to drive the loco, make sound, and do the lights it is capable of and then add a function-only decoder to control additional lights. A TCS FL2 or FL4 function decoder is quite flexible as well as small. The Tsunami can control four lights (functions) which could be headlight, backlight, left FWD ditchlight, and right FWD ditchlight. To add the two rear ditchlights, the 2 function decoder (FL2) would do fine. More lights, use the FL4. The main reason I suggest this is .... a motor decoder is going to be moderately sized (not necessarily big tho) and the function decoder is likely smaller. If you use an N or Z scale decoder however, they'd be close in size so maybe you could let one of those be the motor drive. However I see no advantage in that and you'd pay a little (not a lot) more to add a SMALL motor decoder. You're adding circuitry and cost for something you're not going to use. Just my opinion, you mileage may vary

Lyle

[Deleted]

When you say a chip to do ditch lights but not a decoder, what do you mean? I wondered if an accessory decoder for ditch lights (and in some cases marker lights) might be the answer? But as I will have a decoder in the units anyway I thought it would be better to keep this.

[navy4422]

Sept 20, 2012 13:51:26 GMT -5 @thesd80macbeast said:

When you say a chip to do ditch lights but not a decoder, what do you mean? I wondered if an accessory decoder for ditch lights (and in some cases marker lights) might be the answer? But as I will have a decoder in the units anyway I thought it would be better to keep this.

Sorry I'm rather new to DCC as well it is called a decoder but it pretty much controls just the lights.

[Deleted]

Well this thought had occurred to me. Rather than complicate the issue can a decoder (motor or accessory) be used just to control certain lighting functions?

However, I have come to the conclusion that it may be easier to use the sound decoder for the ditch lights so that they activate with the horn but I don't know how all of this works so I am not sure if using a seperate decoder for lighting functions will work. I guess so long as you controlled the headlight independant of your direction it would work fine.

[Mark R.]

The problem is the fact Tsunami decoders only have two or four function outputs (depending on the model). For front and rear headlights, plus front and rear alternately flashing ditchlights, you need a minimum of six function outputs. To do this with a Tsunami sound decoder, you will have to piggy-back a two-function accessory decoder with it - which could be the DCC only decoder you are currently using.

You could use the Tsunami decoder for your motor / sound / lights as a start and use your current decoder for the additional functions. Whichever decoder you are not using for motor control will need the speed table set to all zeros so it is not trying operate a motor output that isn't there. Depending on the decoder, you will also need to add a 100 ohm resistor across the motor terminals in order to program it as most decoders require an ackwowledgement pulse from the motor to accept the program commands.

For prohramming two decoders in a single engine, you have a couple options. You can program them both to the same address providing at least one decoder has a lock feature so you can program the other without altering the CVs in the first. If neither have a lock feature, you can give them each their own address for programming purposes, then just mu the two addresses to function as a single unit. Remember to program the mu'd decoder to respond to the appropriate commands for the additional lighting when in a consist.


Mark.

[Deleted]

So using the Tsunami for motor control would be better then using the decoders already installed? Can it be done either way or will the Tsunami not accept notching commands if the speed table is set to zero all the way.

I do kinda figure that the Tsunami would be best set up normally and then use the other decoder for the extra lighting functions. Would it be best to use another Soundtraxx decoder to do this so I can get the lock function?

[lyled1117]

Sept 20, 2012 17:58:59 GMT -5 @thesd80macbeast said:

So using the Tsunami for motor control would be better then using the decoders already installed? Can it be done either way or will the Tsunami not accept notching commands if the speed table is set to zero all the way.

That depends mainly whether you have the room to do it or not. If there's already a full decoder installed and you have space for the Tsunami (and lighting resistors if required), then let the Tsunami be a sound/additional-lighting decoder. If you're tight for space, you might have to pull the existing decoder and replace it with the Tsunami and then use a smaller function only decoder. All of the scenarios explained will work if you have the space.

Sept 20, 2012 17:58:59 GMT -5 @thesd80macbeast said:

I do kinda figure that the Tsunami would be best set up normally and then use the other decoder for the extra lighting functions. Would it be best to use another Soundtraxx decoder to do this so I can get the lock function?

There's no reason you have to have the lock, its a personal preference. When I do a dual decoder install I set the short address of one decoder to "3" (factory default) and the other to "4", then give them both the same long address. If I need to alter only one, on the mainline you can tell the long address loco to convert to short address (change CV29) at which point you can program either loco 3 or loco 4 as desired (on the main). When done, tell each short address loco to use its long address and they're both back in 'consist'. However, if you use the program track, both locos will be changed as the program track is a 'blind' method. Any and all locos will change regardless of address on the program track.

If you feel the lock method is preferable, several decoder manufacturers (but not all) have a 'lock' function. Just check and see if the decoder you'd like to use does.

Lyle

[Deleted]

I've no preference towards lock functions but I was reading about it in a kalmbach book so thought it was a requirement especially when it was mention above.

If you can only programme on the main is it possible to re-map the CV's so that the functions are arranged as desired across the two boards?

Talking of consisting, are there are any problems consisting dual decoder loconotives? I've heard of and experienced problems consisting sound and non-sound loco's. Does a dual decoder loco have any issues consisting with other loco's whether they are sound powered or not?

[lyled1117]

Sept 21, 2012 3:36:17 GMT -5 @thesd80macbeast said:

I've no preference towards lock functions but I was reading about it in a kalmbach book so thought it was a requirement especially when it was mention above.

This is strictly my opinion, but the lock function I feel is aimed at those who feel the need to protect themselves from themselves doing something accidental to change their decoders. However, there is legitimate use for the feature as in the dual decoder subject we're discussing here.

Sept 21, 2012 3:36:17 GMT -5 @thesd80macbeast said:

If you can only programme on the main is it possible to re-map the CV's so that the functions are arranged as desired across the two boards?

Absolutely. However you need to be able at times to talk to only one decoder or the other so you have to have a way to make that happen. You could have a way to disconnect one decoder or the other from the track (power) so only the powered decoder makes the changes. You could use the lock as described, but you might want locks in BOTH decoders so you can unlock the one you want to change and relock it when done. You could do the long address to short address back to long address method I described.

Sept 21, 2012 3:36:17 GMT -5 @thesd80macbeast said:

Talking of consisting, are there are any problems consisting dual decoder locomotives? I've heard of and experienced problems consisting sound and non-sound loco's. Does a dual decoder loco have any issues consisting with other loco's whether they are sound powered or not?

If your issues have been in speed matching two (or more) locos with respect to when they start to move , then there are no issues in consisting dual decoders. There can be delays in sound changes (engine exhaust) relative to a motor starting to turn, but that's true even in some single decoder installs and is true for Tsunamis. Adding some momentum can disguise that to a degree if you dislike that. However (real world) locos are capable of moving in notch 1 so a loco can move with out an apparent change in engine RPM.

Lyle

[Deleted]

To be honest I am probably one of those people who needs the lock function to save myself from doing something!

The issues I have had may have revolved around speed matching, I hadn't really considered that. I did consist a sound and non-sound loco, this immediately resulted in no response and when I got my loco's home to the program them I had no problems setting up the non-sound loco. The sound loco, however, took days for me to figure out what to do (and I cannot remember it now) but I eventually managed to reset it and get it working, but all the set-up I had done had changed and it never worked the same.. I sold it on evilbay, the buyer seemed happy but I wasn't. That loco ran a Digitrax decoder so I don't know how different a Tsunami will be.

[nssd70m2]

Your best bet is the FL2 paired with the Tsunami. I'm in the process of getting my MTH SD70M-2 converted to Soundtraxx (it's a pain in the butt by the way) but I am considering the FL2 as it is exactly what I need to run just the rear ditch lights. I may end up getting the FL4 if I want to wire the number boards to come on with a button but we will see.

[tpwillie]

I think the Tsunami with an add-on lighting decoder is a big pain. I have done some work with dual decoders and it only frustrated me.

I would suggest that you get a QSI Titan decoder. It will solve your requirement questions. It has 10 lighting outputs on the one board. Plus it will support 2 speakers in stereo mode. This allows you to have the horn and bell in the front where it belongs plus a whole host of other sounds. Take a look at the installation manual to get an idea of what it can do:
www.qsisolutions.com/pdf/titan/Titan_U_Diesel_Rev_C_3-15-12.pdf

I think this is the easiest solution and takes up the least amount of space. They do have an Atlas style board also if that is what you need.

Lou

[Deleted]

Jan 3, 2013 1:59:10 GMT -5 nssd70m2 said:

Your best bet is the FL2 paired with the Tsunami. I'm in the process of getting my MTH SD70M-2 converted to Soundtraxx (it's a pain in the butt by the way) but I am considering the FL2 as it is exactly what I need to run just the rear ditch lights. I may end up getting the FL4 if I want to wire the number boards to come on with a button but we will see.

Pardon my ignorance but what are FL2 and FL4?

[Deleted]

Jan 3, 2013 21:48:24 GMT -5 tpwillie said:

I think the Tsunami with an add-on lighting decoder is a big pain. I have done some work with dual decoders and it only frustrated me.

I would suggest that you get a QSI Titan decoder. It will solve your requirement questions. It has 10 lighting outputs on the one board. Plus it will support 2 speakers in stereo mode. This allows you to have the horn and bell in the front where it belongs plus a whole host of other sounds. Take a look at the installation manual to get an idea of what it can do:
www.qsisolutions.com/pdf/titan/Titan_U_Diesel_Rev_C_3-15-12.pdf

I think this is the easiest solution and takes up the least amount of space. They do have an Atlas style board also if that is what you need.

Lou

I recently saw these and have been mulling them over because it seems so much easier but I think Tsunami sound so much better. In the end I may just have to compromise!

[lyled1117]

Jan 4, 2013 6:48:19 GMT -5 @thesd80macbeast said:

Pardon my ignorance but what are FL2 and FL4?

These are function only decoders made by TCS (Train Control Systems). Quite flexible in my opinion.

Lyle

[Deleted]

Jan 4, 2013 9:50:55 GMT -5 lyled1117 said:

Jan 4, 2013 6:48:19 GMT -5 @thesd80macbeast said:

Pardon my ignorance but what are FL2 and FL4?

These are function only decoders made by TCS (Train Control Systems). Quite flexible in my opinion.

Lyle

That's food for thought, might have to look into those before I look into the Titan.

Sent from my GT-I9100 using proboards

[nssd70m2]

It seems a lot of people in the model railroad world have issues with having 2 decoders installed in their locomotives. (I actually placed my order for the Tsunami and FL4 today by the way.) The easiest way to get around having the dual decoder issue is to install a 2 pin quick connector to the power inputs of each decoder. That way if you need to re-program a decoder after it's already installed, all you have to do is open the engine up and disconnect the plug. My plan of attack is to initially program each decoder separately before I connect them both up to track power. That way all of my CV's I want changed are exactly what they should be, and my locomotive addresses for each decoder can match.

[nssd70m2]

Actually let me take that back. Tsunami and TCS support the decoder lock feature! Use JMRI and programming them separately will be a piece of cake.