Question on DCS and MTH HO

Is Fix 1 powered?  It needs to be since it powers the TIU.  G

I haven't looked, is there a diagram in the engine manual, or the DCS manual, or on the website that shows correct hookup for HO MTH engines. Would 2 rail O scale (MTH engines) be the same hookup?

Gentlemen,

 

The connection is the same as for 3 rail AC except that:

• DC + should go to the Red TIU input terminal
• DC - should go to the Black TIU input terminal.

It makes no difference which output terminal is connected to which outside rail. PS3 HO engines are insensitive to which rail has DC + and which one has DC -, and can pick up the DCS signal from either rail.

 

Regardless, as GGG stated above, either use Fixed Channel #1 or use another channel with power to the TIU's Aux. Power port.

 

If you just use Fixed Channel #2 without power into Fixed Channel #1 or the Aux. Power port, the power will get to the tracks, however, there won't be a DCS signal present at all.

 

Further, you cannot use Variable channels at all with DC power.

Barry, Since you cannot use the Variable channels with DC power would applying DC power to one of the variable channels cause any problems with the TIU or would it just not work?

Hi Barry.  I'm using a 2 rail track.   I have the power in Fixed 2 and running to the track on fixed 2 but the locomotive isn't being found.   Its strange because it was found immediately when I accidentally had it on AC.   Does the remote have to be set for fixed 2 as well and if so how?

 I have the power in Fixed 2 and running to the track on fixed 2 but the locomotive isn't being found. 

Regardless, as GGG stated above, either use Fixed Channel #1 or use another channel with power to the TIU's Aux. Power port.

 

If you just use Fixed Channel #2 without power into Fixed Channel #1 or the Aux. Power port, the power will get to the tracks, however, there won't be a DCS signal present at all.

Would I used Fixed #2 for my AC power because right now I have it on #1.

texmaster... The tiu need a power supply to function (turn on) operate.

 

Power to Fixed 1 or an aux power supply or both will turn the tiu "on". It's kind of like a radio, if you don't turn it on it won't work

 

 

Ah ha - I just remembered something!

 

Some time ago, Marty and I discovered that if you use DC with a TIU channel but power the TIU with AC through the Aux. Power port, the engine on Fixed #1 won't respond to DC voltage!

 

Try using only DC into Fixed #1 for the HO engine, with either DC power or no other power into the Aux. Power port. If that works, we can move on from there.

Wow.  That is interesting, never would have thought since FIX pass thru.  Does it not respond to DC or does the TIU prevent a DCS signal from being put onto Fix 1 output?  G

G,

Does it not respond to DC or does the TIU prevent a DCS signal from being put onto Fix 1 output?

As I recall (and it was some time ago) the power got to the engine, however, we couldn't do a sound file transfer. When the Aux. Power input was changed to DC, the same as track power, all was well.

 

I never did attempt to determine why things were that way.

       
       



Well Barry that worked putting the DC into fixed 1.  Now the question I have is where do I put the ac power for the three tracks?  Fixed 2?

Now the question I have is where do I put the ac power for the three tracks?  Fixed 2?

You can use the other 3 channels for AC or DC operation. Just be sure that, when using any of these channels, you do one of the following:

• Have power turned on into Fixed Channel #1 IN
• Have DC voltage connected to the TIU's Aux. Power port.

Hi Barry,

 

If I use the aux for DC, the only way so far I could get the HO engine to respond was to use Fixed #1 for power and for the track.   If I move DC power to the aux and plug in AC power to Fixed #2 will the TIU be smart enough to only send DC power to the HO engine via fixed #1 output?

 

Here is my current layout without the power plugged in for the AC side but you can see Fixed #2 has a power plug out there.  The Gold Banana plugs are for DC power and DC track.  All  3 AC tracks run through the block.

 

If I move DC power to the aux and plug in AC power to Fixed #2 will the TIU be smart enough to only send DC power to the HO engine via fixed #1 output?

It's not a matter of being "smart". Rather, each TIU channel passes the voltage that it's given, AC or DC. There's no way to convert one to the other.

 

If you want to use DC on either fixed channel (Variable channels do not pass DC voltage) you must also power the TIU itself with DC, either via Fixed #1 IN or the Aux. Power port.

There's a little pearl from you Barry!  I was wondering if it made a difference what I powered it with.  If I'm using AC through the track inputs, can I power it with DC via the AUX power, or must it be AC?

 

John,

I was wondering if it made a difference what I powered it with.  If I'm using AC through the track inputs, can I power it with DC via the AUX power, or must it be AC?

I've never tried it so be sure to let me know what you find out!

 

I'm not inclined to risk letting the magic smoke out of my TIU, thanks.

 

So if I understand you guys correctly I can't have AC and DC plugged in at the same time to power different tracks?

 

Because doesn't the AC need to be on fixed for DCS which would mean I can't power fixed #1 with DC and fixed #2 with AC?

You're understanding Barry, I'm riding along to find out the answer myself, I haven't used DC with the TIU at of now.

 

So if I understand you guys correctly I can't have AC and DC plugged in at the same time to power different tracks?

All that I know for sure is that if you have AC on either Fixed #1 or the Aux. Power port, you canot operate using DC on any channel.

 

I suspect that as long as the Aux. Power port has a DC power supply, one can use DC or AC on the fixed channels, and AC on the variable channels.

 

Thanks Barry!   I'll give it a shot!   I was only concerned if I used the aux port for the DC current and plugged the AC current in would the tiu know to only send DC power to the HO train and not AC.

Since HO draws so little current, you may want to let FIX1 be DC and forgo even using Aux Port.  Just let your good DC power Supply feed the TIU.  G

G,

Since HO draws so little current, you may want to let FIX1 be DC and forgo even using Aux Port.  Just let your good DC power Supply feed the TIU.

The only problem with that, is that if Fixed #1 goes off the air (derailment, breaker trips, fuse blows), Fixed #2 loses control and both Variable channels go dead. Not really a good idea.

I understand how FIXED #1 might interact if fed DC to power the TIU, but I would think that the aux power type would not matter to the TIU power channels.  Hard to believe it doesn't get converted to DC pretty early anyway to power the logic.

John,

 

I'm not writing the news, I'm just reporting it.

Good Point.  G

I called MTH and they couldn't understand why Fixed 2 did not work for DC power but Fixed 1 would.  They claim both are isolated so it shouldn't be a problem.

I called MTH and they couldn't understand why Fixed 2 did not work for DC power but Fixed 1 would.  They claim both are isolated so it shouldn't be a problem.

I would agree. When you tried Fixed #2 with DC, what else was connect to Fixed #1 and the Aux. Power port?

Surely he doesn't have an original TIU version "G"?

 Hmmm, I didn't take the time to figure it out. I just got a second TIU when I switched the G scale layout to DC. There were some weird things happening and it's funny now to look back at this conclusion. At first, I blamed the type of power supply which later worked great. I was told that it probably had too much noise, and it did not. Unfortunately that cost me a lot to replace it and the TIU only to find this out later.

Nothing since I was adding the HO engine

That's a good point and I have checked.  Its an "L"

Nothing since I was adding the HO engine

In that case, of course it couldn't work because the TIU wasn't powered up.

       
       


Ok so the tiu only gets power through fixed 1 or the aux.  That was my error

First off I want to thank everyone especially Barry for being so patient with me and my questions.    I was able to run the HO in Fixed #1 and the AC O guage in Fixed #2 using the power supplies plugged into the respected Fixed inputs.

 

However the joy did not last long.   I first powered up the HO and then connected power to the AC trains on fixed 2 and everyone was working for about 2 minutes.    I looked over and the HO engine had stopped.    The headlight off and just sitting there with no sound.  The horn and bell still worked but it did not budge and did not respond to start up or power down commands.

 

I had the exact same issue on fixed 1 when I had all 3 of my AC O guage MTH engines running without the HO track.  (see this thread for details  https://ogrforum.com/t...67#22970455006463067 )   One of them after about 2-3 minutes simply stopped dead in its tracks.   Headlight off and only would respond with horn and bell.   No matter how many times I powered down the TIU it never got it to move.   Not until I hooked up that track to a  more basic MTH controller.   Then it began to move again with a lot of coaxing and when hooked back up to the TIU began to respond again.

 

I'm really starting to wonder if my fixed #1 channel is simply bad.   I'm scared to death to run the O guage engines for any long period of time now because of what happened earlier.    Is this a bug in the TIU or the software anyone has heard of?

I'm really starting to wonder if my fixed #1 channel is simply bad...Is this a bug in the TIU or the software anyone has heard of?

If you can start up an engine on a channel, however, you can only do some DCS functions after starting up the engine (bell, horn or whistle, sounds) but not others, my best guess would be that the problem is the engine. The next time this happens, try doing a track signal test.

 

Now, as to the cause of the problem, that's more difficult to say. It could be a defect in the engine, something in the layout's wiring or track work, or power supply. You'll need to provide more detailed information as regards exactly what you do and exactly what is the result in chronological order.

 

One question: do the engines recover their complete functionality sometime after the problem event?

For clarification this has happened on 3 different tracks with 3 different engines.  2 O and 1 HO.

 

The symptoms are very clear.   The engine will simply stop dead in its tracks.   All outside lighting from cars will work so the track is getting power but the engine itself will not move and will not respond to any commands other than the whistle and bell.

 

When this has happens the most important thing is if you remove the engine from the remote you will never get it back in its current state.  ie you can never re add it because it will never be found.  When this happened to two different o gauge engines both times a more basic MTH controller was needed to clear whatever DCS interference was preventing normal operation.   After about 5 minutes of messing with the back and forth and doing the bell and whistle code clearing, functionality returned to both O guage engines and then after reconnected to the TIU they were re added and continued normal operation.   Now that its happened to my HO I will probably have to find a basic HO controller to power it up and clear the DCS issue.

Just for giggles, connect the TIU's Remote Input port to the port at the bottom of the  remote with a 4-conductor telephone handset cable. That's the curly one that goes between the phone base and the handset, not the one between the wall and the phone base.

 

If the problem doesn't recur, we can talk about how to make things right.