Digitrax "Track Power" button

[Ed Kapuscinski]

Has anyone ever come up with a way to add a "track power" toggle button to their layout?

I know you're supposed to toggle it via the power button on throttles, but I wonder if there's another way to do it.

[John]

You could make it work with jmri or any device that can send a loconet command such as pi or arguing.   Push physical button and device sends. ..l in jmri it’s probably a Logix. 

[Sokramiketes]

Like a... power strip? 

What's the use case for the track power being toggled frequently enough to utilize a button on the layout?

[C855B]

You could make it work with jmri or any device that can send a loconet command such as pi or arguing.   Push physical button and device sends. ..l in jmri it’s probably a Logix.

Oo! Great idea! I might try that this afternoon when I make it over to the studio.

The Grand Plan was to have physical panic buttons in strategic locations. If it can be a virtual button on a soft panel controlling a yard or junction - which are being/to be implemented on tablets in several locations - those will do, as well. I could easily create a JMRI panel that is nothing but a big red button, the resulting web page sized for a discarded smartphone tacked to the fascia.

Certainly not the same as hardware interruption of power, but since the panels communicate with JMRI over Wi-Fi and are not on Loconet, it’s a 99-44/100% solution.

[John]

In JMRI - the easiest way would be to connect to a sensor input such as on a DS64, or SE8C or equivalent .. one side of the switch goes to the ground and the other to the input .. use a momentary switch ..


Here is the code . its found under the Jython directory in JMRI

# Turns layout power off.
#
# Invoke this from a Logix in response to your desired e-stop command,
# e.g. a panel button that operates an internal sensor
#
# Author: Bob Jacobsen, copyright 2013
# Part of the JMRI distribution

import jmri

powermanager.setPower(jmri.PowerManager.OFF)

[C855B]

What's the use case for the track power being toggled frequently enough to utilize a button on the layout?

For one, short-induced runaways. Bachmann decoders are notorious for that. Run into a switch set against you, and suddenly “parked” Centennials (or whatever) in the power district are doing their damnedest to take a nose-dive off the benchwork.

And collision prevention in moments of “Where’d I put that throttle?” while multi-tasking.

Both from hard experience.

[Rivet Miscounter]

Has anyone ever come up with a way to add a "track power" toggle button to their layout?

I know you're supposed to toggle it via the power button on throttles, but I wonder if there's another way to do it.

https://www.digitrax.com/tsd/KB529/ds54-emergency-stop-application

This is an Emergency STOP solution, but it won't turn it back on.  I'm not sure if you were simply looking for an extension to the track power or if the idea was as an emergency measure.  But a good thing to know regardless.

It would be neat if you could have both.   A large "RED PLUNGER" e-stop, and an adjacent smaller (harder to accidentally press) button(s) to reset, power up, etc.

Next level would be "ALEXA TURN OFF LAYOUT".... (you could accomplish that with a Smart Plug to cut power...not sure if that's the cleanest method.)

[jagged ben]

Making an assumption here, but I assume the code to turn it back on is.
(powermanager.setPower(jmri.PowerManager.ON)

Make it a toggle switch instead of a momentary button, or use two momentary uttons, or just keep the one.  Program logix accordingly. Done.

[DMU-Fan]

You mean like this?

https://www.rpc-electronics.com/tedp.php

[C855B]

You mean like this?

https://www.rpc-electronics.com/tedp.php

Interesting, but not what I'm after, which is a whole-layout master panic "smash" button in multiple locations. What you might not know (but the others here do) is my layout is 44'x40', multiple DCC power districts, running under JMRI with Wi-Fi throttles only.

That said, I have the solution already programmed, I just need to gussy it up for a web page on a discarded phone (I have several) to make it big and obvious.

It turns out power operators are already in LogixNG, so no need to do anything in Jython. This application is power off only, with no ability to reset from the panic button. I may or may not code a tell-tale (which button got smashed), but my philosophy is that somebody must have a throttle in-hand to restore operation, or is at the dispatcher console.

[DMU-Fan]

Interesting, but not what I'm after, which is a whole-layout master panic "smash" button in multiple locations. What you might not know (but the others here do) is my layout is 44'x40', multiple DCC power districts, running under JMRI with Wi-Fi throttles only.

That said, I have the solution already programmed, I just need to gussy it up for a web page on a discarded phone (I have several) to make it big and obvious.

It turns out power operators are already in LogixNG, so no need to do anything in Jython. This application is power off only, with no ability to reset from the panic button. I may or may not code a tell-tale (which button got smashed), but my philosophy is that somebody must have a throttle in-hand to restore operation, or is at the dispatcher console.

Got it! Yeah, my solution is for a MUCH smaller layout!

[greenwizard88]

My friend has an ancient NCE system, and occasionally if you send too many commands at once it gets confused, and all of the very expensive brass or BLI or BLI brass steam engines start moving at full speed.

His solution was not to buy a new DCC system.

His solution was to run a wire from the DCC system, all the way around his layout, back to the start, and then to the track. This wire has multiple decora style switches, and smashing any one of them will break the circuit, and remove power from one of the rails. Effectively it's multiple panic buttons.

[nickelplate759]

Clever and cheap!  I like it!

[mmagliaro]

Far and away, I like greenwizard88's solution the best.  If the intent here is to provide a panic button to cut the power in case "something goes wrong with the DCC system", the last thing you want is to be relying on the DCC system or any other computer or electronics to be in between your panic button and track.  This is a case where it should be as old school as possible.

The only downsides are that you have to run a big ol' loop of wire around the whole layout to wherever you want a panic button, and the buttons themselves have to be beefy enough to carry your full short-circuit worst-case booster current.  Another complication would be if you have multiple boosters going to different zones of track.   

You could handle muliple boosters with relays. Get some heavy current 15A relays (surplus automotive relays would work well for this, and you can buy them at places like jameco pretty cheap).  You need one relay for each booster.  Run one output lead of each booster through the normally-open contacts of a relay and then on to the track.     All the relay coils are wired together in parallel and powered from some handy separate power supply (SEPARATE FROM THE BOOSTERS)., and one leg of that separate power supply goes through  the loop around the layout with all the panic buttons.
When the layout powers on, all the relays close, so all your boosters are connected to the track.  If you push any panic button, it cuts power to all the relays, dropping them open and cutting all the boosters off from the track.  The number of relay activations is tiny (after all, how many times do you power your relay on and off), and the relay only flips on at startup when there will be no trains running, so no load through the contacts.  In other words, relay wear will be minimal and they will last "forever".

Now, the wire loop around the layout can be small gauge wire, there is no concern about voltage drop through that long around-the-layout loop because it's not carrying track power, and the panic switches can be any toggle or push-on-push-off type of switch - they don't have to be big heavy-current switches.



Whichever "old school" scheme you use, do set it up so that the track is only powered if the relays (or cut-out switches) are working.  In my example with the relays, notice that if something goes wrong (like the separate power supply for the relays get unplugged), then when you turn on the layout, all the tracks will be dead.  That's how you want it.  You don't want a system that relies on wiring or power being functional in order to cut off the power.