Help needed using TIU Variable input 1/2

Set your variable channels to fixed. It's also explained in Barry's book. Been a long time since I did this or I would provide more details, but you may have to set the voltage to 18 volts too, sorry, I can't remember exactly without digging out Barry's book.

Not sure how you have your Legacy control wire connected, but I have mine connected to ALL commons on my TIU outputs. You just have to make sure the Legacy signal gets to the tracks on your new electrical district.

RTR12 many thanks

Eliot

You are welcome. I was hoping Barry would be by to comment, or GRJ or someone that's done this a few times.

Also, I don't remember ever setting up a TIU track to get fixed outputs on the variable channels? I am not sure that is needed.

RTR12,

I was hoping Barry would be by to comment,

No need, you handled it just fine - thanks!  

Thank You! Even a blind hog gets a piece of corn once in a while. 

RTR12 . . . . With your advice and Barry's book I was able to change Variable Input1 on the TIU to Fixed and it now works fine as do Fixed Inputs 1 and 2. All functions of my locomotives are operational. Variable Input 2 was switched to Fixed also (confirmed by the remote) but the loco does not respond although it lights. Any suggestions for what I might do or what the problem could be? Could one channel be having a problem?

Eliot

Eliot,

but the loco does not respond although it lights.

Some questions:

• Is this a Legacy engine or PS2/PS3?
• Does it run OK on any of the other TIU channels?
• Do other engines of the same work OK on this channel?

Barry,

Many thanks for reading this thread and taking the time to respond.

1) Loco I am referring to in this thread is Legacy. DCS locos run fine on the other channels (Fixed 1 or 2)

2) Loco in this thread runs fine on the other channels

3) Yes, other Legacy locos work fine using all other channels including Variable 1 changed to Fixed.

The only problem right now is Variable 2 and using it converted to Fixed. Locos light up but do not respond.

BTW, I checked power output from the ZW-L handle BU which I am using to feed the TIU and output is fine. I connected handle BU to other circuits with 100% function.

A mystery . . I do have a second, new, TIU I can use for additional channels. I was planning that anyway.

eliot

Eliot,

The only problem right now is Variable 2 and using it converted to Fixed. Locos light up but do not respond.

Since all of your Legacy engine exhibit this bad behavior only on this TIU channel, this does not appear to me to be related to either track power, the engines, the TIU or DCS. I would, instead. look at how you're getting a Legacy signal to the tracks connected to that variable channel.

Unless your TIU is an original, Rev. G, model, it's TIU channel's AC Common outputs are not connected internally. This could cause that variable channel to not have a Legacy signal present unless you took steps to ensure that it does.

Is the Legacy engine, perhaps, coming up in conventional mode?

I will defer to Barry on this one, he's much more qualified than I am. Glad you got most of it working though.

Barry,

For each of the three channels working properly, I have connected the Legacy base to a bus bar and from the bus bar I have run a wire to each TIU Input. That works for the other three channels and I did the same for Variable2.

I will revisit the wiring to be certain there is proper contact.

Embarrassing to say, I do not know if the Legacy loco is coming up in conventional. It does not move nor have any function beside a light in the cab.

Thanks again

Eliot

Eliot,

I have run a wire to each TIU Input.

First, the connection should be to the TIU's output, not it's input. No good can come of passing the Legacy signal though a DCS signal generator.

do not know if the Legacy loco is coming up in conventional. It does not move nor have any function beside a light in the cab.

It would be very good to know this.

You will want to put the Legacy signal on the output of the TIU.

Thanks, Barry.

I will reroute the Legacy base signal to the TIU outputs and let you know what happens. Thanks for your suggestions.

Eliot

Depending on the version of Legacy loco, the older locos will come up in forward. At full voltage they will take off like a bat out of hell

Most TMCC and Legacy locomotives will take off the second time they are power cycled in conventional.  Upon power on the very first time after running command mode, the locomotive will come up in neutral.  The next power cycle if there's still no TMCC track signal, then the locomotive will come up in forward, and as Matt says, with 18 volts, it'll take off at a pretty good clip until the first curve.