Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Turning Off A Specific Signal

1798 views
12 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September 2013
  • 2,505 posts
Turning Off A Specific Signal
Posted by caldreamer on Tuesday, March 22, 2022 8:35 PM

Is it possible to turn off all of the signal heads of a specifc signal signal to make it look like the signal has failed.  I will be using DCC to control the signal aspects.

  • Member since
    August 2020
  • 84 posts
Posted by MrMe on Tuesday, March 22, 2022 10:12 PM

There are lots of combinations of hardware/software that can be used to drive signal heads, so I would imagine it depends on the specific combination you're going to use. 

But since approach-lit signals are a thing, it should certainly be possible.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, March 23, 2022 6:13 AM

caldreamer
Is it possible to turn off all of the signal heads of a specifc signal

of course it's possible

there's no reason you couldn't add a switch to simply unpower the LED if not add a pseudo aspect that results in a lamp being black

greg - Philadelphia & Reading / Reading

  • Member since
    September 2003
  • From: Omaha, NE
  • 10,621 posts
Posted by dehusman on Wednesday, March 23, 2022 6:38 AM

caldreamer

Is it possible to turn off all of the signal heads of a specifc signal signal to make it look like the signal has failed.  I will be using DCC to control the signal aspects.

The question is, why would you want to do that?  Its a relatively rare thing.

Dave H. Painted side goes up. My website : wnbranch.com

  • Member since
    September 2013
  • 2,505 posts
Posted by caldreamer on Wednesday, March 23, 2022 8:14 AM

I am writing a program to run my railroad that will incorporate everything that a real railroad encounters including weather.  One of the things that I will incorporate is defects such as a signal going dark, any or all of the defect detectors or a bad switch, etc.

  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, March 23, 2022 8:39 AM

caldreamer
I am writing a program to run my railroad that will incorporate everything that a real railroad encounters

i'm curious when your program would decide to create such a problem?   1 in a 1000 times?

as suggested, some software determines aspect to generate (STOP, APPROACH, CLEAR, ...) and relies on other hardware to determine how to indicate it (red, yellow, green, ....).   you could also inclulde pseudo aspects (e.g. CLEAR-DARK) that indicate a dark lamp.   (what about a faulty semaphore.

besides determine that a detector is faulty, do you also want to randomize what it reports: false occupied or false unoccupied.

presuambly a faluty switch is similarly handled by misreporting it's position.  does this mean the interlocking logic simply forces a STOP indication because the desired switch position doesn't match the reported position.

 

seems that a "defect simulator" would be a separate module that interfaces between the control program and the layout peripherals and randomly cause these defects.   presumably a defect simulator could easily be removed or disabled

greg - Philadelphia & Reading / Reading

  • Member since
    April 2004
  • From: Ontario Canada
  • 3,574 posts
Posted by Mark R. on Wednesday, March 23, 2022 8:58 AM

For signals to be dark due to a failure is rather rare. In case of line power failure, there is normally battery chests to minimally keep the lamp powered. By default, the signal mechanism drops to the red lens when power is lost, so the crew would at least get a red indicator regardless of actual track conditions.

Some railroads at one time did go to a dark indicator when there was no activity within two (or more) blocks in either direction from the signal. The concept was nothing more than a conservation attempt. 

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
    September 2013
  • 2,505 posts
Posted by caldreamer on Wednesday, March 23, 2022 9:04 AM

The frequency of a signal losing inication has not been determined since I have not written that piece of code yet. The indication of when a block is occupied will be handled by a block occupancy detector which will report back to the ctc display showing where the train is.  That module is already written.  BTW:  I am writing my program using the Java programming language and using a sql database to store all of the data that is used by the program.

  • Member since
    September 2002
  • 7,486 posts
Posted by ndbprr on Wednesday, March 23, 2022 12:46 PM

Well if realism is what you are after you could always cut the wires. Then you could station a flagger there until the signal maintainers could troubleshoot and fix it. Maybe not.

  • Member since
    August 2020
  • 84 posts
Posted by MrMe on Wednesday, March 23, 2022 2:16 PM

Maybe I'm missing something here, but how can you be writing the program to control the hardware if you don't know what the hardware's capabilities are?

Also, you do know that an open source project written in Java to do all this (and a whole lot more), with a good number of prototype-specific signaling systems included, already exists?  See https://www.jmri.org/xml/signals/

  • Member since
    September 2013
  • 2,505 posts
Posted by caldreamer on Wednesday, March 23, 2022 3:49 PM

I do know wht the capabilities of the hardware are (Digitrax has everything that I need).  I will be using pieces of the JMRI code.  I wil incorporate the CTC capabilites and have written parts of my program to use for example a python script to stop a train if it violates the PTC rules.  The full PTC module logic has already been written.  

  • Member since
    August 2020
  • 84 posts
Posted by MrMe on Wednesday, March 23, 2022 5:20 PM

Okay, I guess it must be me, because I'm having a hard time understanding why you'd be asking this:

caldreamer

Is it possible to turn off all of the signal heads of a specifc signal

...if you're also telling us this:

caldreamer

I do know wht the capabilities of the hardware are

Oh well, doesn't matter. Question asked and answered.

  • Member since
    January 2009
  • From: Maryland
  • 12,897 posts
Posted by ATLANTIC CENTRAL on Wednesday, March 23, 2022 5:42 PM

caldreamer

Is it possible to turn off all of the signal heads of a specifc signal signal to make it look like the signal has failed.  I will be using DCC to control the signal aspects.

 

As already mentioned prototype systems have had a number of redundant safety features going WAY back.

Component failure, like a bad relay, almost always just results in a restrictive indication. Batteries back up the regular power supply, lamps are/where replaced on schedules before typical failure age.

Do what ever makes it fun for you, but I don't model disaster, or crime.

Sheldon 

    

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!