watchdog signal

does the tiu only put out this when it is first given electricity.  I have two proto2 engines on a siding that I turn off center rail power to when not using and if the power is on the main line and I add  power to the siding both engines come on

Your engines are working fine.

From Page 25 of The DCS O Gauge Companion and Edition:

The TIU sends out a watchdog signal whenever the output of a TIU channel changes from zero to any higher voltage. This signal only lasts for a brief period of time, however, this is generally long enough for a PS2 engine's electronics to recognize the watchdog signal and cause the engine to come up in DCS stealth mode, dark and silent.

If a PS2 engine misses the watchdog signal, it can be forced into DCS mode by pressing either Start Up or Shut Down while the engine is displayed in the DCS Remote's LCD screen. If Start Up is selected, the engine will come up in DCS mode ready for operation, making sounds and displaying lights. If Shut Down is selected, the engine will become dark and silent in DCS stealth mode, waiting for a future Start Up command.

This and a whole lot more is all in "The DCS O Gauge Companion 2nd Edition", now available for purchase as an eBook or a printed book from MTH's web store site! Click on the link below to go to MTH's web page for the book!

There was some way of tricking it isn't there Barry?  Starting the VAR at 18v then going to 22v?  I managed to get it set up that way on one of mine althought I don't recall what buttons I pushed in what sequence to get it set that way.  Four tracks full of locomotives powers up without any of them starting up.  Usually.  Well, most of the time ...

Kerrigan,

There was some way of tricking it isn't there Barry?

I'm not certain that I understand your question.

It sounds like you're asking if you can turn on the power to a siding that is tapped into a powered section and get the PS/2 engines to come up in command mode.  Since the TIU only sends the watchdog signal out when the channel is initially powered, my sense is that won't happen, they'll always come up in conventional mode.  I have two sidings with separate power taps off the mainline, and that's how they always work.

John,

Actually, there is one "trick" that I've found that not only works on individual engines, but also works on lashups. This is important because, unlike single DCS engines, lashups appear to to go into DCS mode when a STARTUP command is issued, however, they cannot be made to actually move.

From page 102 of The DCS O Gauge Companion 2nd Edition:

Missing the Watchdog Signal

If individual PS2 engines miss seeing the watchdog signal, they can be either brought directly into DCS active mode by pressing the Start Up key or put into DCS stealth mode by pressing the Shut Down key. However, this is not the same for lashups.

If a lashup is powered on after the watchdog signal has come and gone, perhaps if its siding was toggled on after voltage appeared at the TIU channel outputs connected to its siding, there are two ways to put the lashup into DCS mode. One way to put the engine into DCS mode is to turn off power to the inputs for the TIU channel that is connected to the track upon which the lashup resides, toggle on the siding and then re-apply power. The other way is to first highlight the engine in the remote's Active or Inactive Engine list. Then, flip the toggle switch and immediately press the thumbwheel to select the engine. It will come up in DCS stealth mode, dark and silent. This also works with individual PS2 engines.

This and a whole lot more is all in "The DCS O Gauge Companion 2nd Edition", now available for purchase as an eBook or a printed book from MTH's web store site! Click on the link below to go to MTH's web page for the book!

Interesting on the MU configurations.  I knew that I could get individual locomotives back into DCS mode easily, but I never tried it with an MU configuration.

I guess I didn't get to that page yet.

If you have an unused DCS Remote Commander lying around, you can attach it to your siding in "passive" mode.  When you apply power to the siding, the DCSRC will generate the watchdog as its sole purpose in life keeping your 2 engines quiet.  I don't know if its worth buying a DCSRC to save a few button presses but if you migrated to the TIU from a DCSRC in a starter set...

Somehow (and I don't remember the "how" ...) I got my coach yard (which is now full of locomotives) to power-up with all the locomotives catching the watchdog signal.  The Track on the remote for it starts at 18v, the dial it up to the full 22v setting.  It works for some reason ....

Stan,

Very clever!

Cool Idea Stan, I do have one of those in the closet.

Stan, That does sound like the bullet proof answer.

Watchdog every time that way, and never have a engine come up conventional at power toggle again.

And also inexpensive to boot.

I forsee purchasing a couple more of these, I have one for the Christmas layout now.

Stan,

There is, of course, one issue regarding using the same DCSRC receiver to control more than one siding. That is, when one siding is powered on, all of the sidings are powered on.

So, following up on Stan's info,

If the siding power switch is a DPST switch, one pole of the switch could turn on the siding, and the other pole could connect the "red" wire from the DCSRS to the siding center rail.  The "black" wire from the DCSRC could be connected to the outside rails on all sidings.

One DCSRC "shared" by all sidings?

Ed

Eddie,

One DCSRC "shared" by all sidings?

This necessitates connecting all of the multiple sidings to the output terminal (at least the red terminal) of the DCSRC, effectively shorting together all of the sidings. As I stated above:

There is, of course, one issue regarding using the same DCSRC receiver to control more than one siding. That is, when one siding is powered on, all of the sidings are powered on.

No,

The second pole of the DPST switch connects the red DCSRC terminal ONLY to the siding that is being powered (by the other pole of the same switch.)

When a siding switch is turned on, one pole powers the center rail and the other connects the DCSRC to the transformer, sending a watchdog.

All sidings are off.  When a siding switch is turned on, the DCSRC gets power and sends watchdog.  When a siding switch is turned off, another siding may be turned on, repeating the DCSRC powerup and a new watchdog.

IMHO,

Ed

I like that Ed, but one minor flaw.  If you have one siding on and then choose to startup another, you don't get the watchdog unless you first turn the first one off.  A cool way to insure this won't happen is a large rotary switch.

John,

 If you have one siding on and then choose to startup another, you don't get the watchdog unless you first turn the first one off.  A cool way to insure this won't happen is a large rotary switch.

Absolutely correct. If one siding is turned on, none of the other sidings can see a watchdog signal.

A cool way to insure this won't happen is a large rotary switch.

True, however, then you can only have one siding powered on at a time.

Right, there is no such thing as a free lunch.   It really depends on how you use the sidings and what flexibility you demand.

I agree John, I always use 1 siding at a time so it works well as described.

The rotary switch solves the one at a time thing, but to get to siding 7, you have to go from 1 to 7 activating all of the sidings momentarily... and it's exclusive.

For multi-siding users, I added a Normally Closed Pushbutton, so if a siding is already on, when a second siding is turned on, pressing the PB (and letting go) will generate a watchdog.

I didn't know about this "trick" but it seems to me to be a boon to layouts with lift out bridges.  Just connect a DCSRC under to bridge connected to the track so whenever the liftout is energized, the watchdog is sent.

Adding to an existing layout? just connect the DCSRC to the track with the NC PB, and press it when you switch on a siding, then release to send watchdog.

Ed

Pizza Ambassador and author of "Pizza Layout, Anyone?"

A nice way to address the sidings would be to use a multi-pushbutton switch for selection.  I know I have a 10 position one somewhere that has a number of contacts.  It insures only one connection and allows direct access to any of them.

I like the button idea, solves the issue of them coming up in conventional.

Ed, a very well-done diagram and explanation! 

I think many guys only run one siding at a time so your original covers many layouts and of course keeps those chronometers at bay on the unpowered engines .

In terms of "adding to an existing layout" a double-pole relay could be used in place of the DPST switches so that existing control panels using single-pole switches could apply this scheme.

For the determined DIY-er, a circuit using a relay, diodes, capacitors, etc. could automatically "press" the NC PB.  So for the multiple simultaneously-powered sidings scenario, when any siding is powered it would momentarily open a relay (instead of the NC PB).  I figure such a circuit would cost less than $5.

Gentlemen,

While quite elegant, this really seems to me to be an overkill solution to a somewhat trivial problem.

To place any unpowered engine or lashup into DCS stealth mode without turning off and on power to a TIU channel, it's only necessary to the following:

• Highlight the engine in the remote's Active or Inactive Engine list
• Flip the siding's power switch
• Immediately press the thumbwheel.

In order to turn on the siding and run the engine, you must do the above anyway, so there's no extra effort.

Why add any more effort, complexity or expense?  

Gee, what a kill-joy!  We were having so much fun designing this elaborate scheme.

I've been okay with the on-off tracks being connected to the VAR terminals, and using on-off switches for the individual tracks ... like in the 6-track yard: it's on VAR1 and also has toggle switches for each track of the 6.

No problems yet, but I'd like to figure out how I made the coach yard start at 18v then ramp up to 22v allowing all the engines sitting in it to come up quiet ....

Verily!

I think even Rube Goldberg might nod in approval of this even more complex Mouse Trap scheme:  When any siding is first powered, it would activate a switch on the DCSRC remote (simulating a button press).  The remote would send the Infrared command to the DCSRC receiver which would send out a track-signal command to a non-existent (factory default address) engine.  This command would effectively be a "watchdog" and keep any engine on that siding silent and in command mode.  This would eliminate the need to interrupt power to the DCSRC receiver.  How's that for elaborate?

C'mon, guys - someone has to remain firmly grounded in reality!  

My BEST solution:  CONVENTIONAL!

Ed