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Getting started with DCC

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Posted by gregc on Monday, September 26, 2022 7:58 AM

the topic is does DCC require less and simpler wiring? 

it certainly can, both in terms of # of wire as well as length of wire (as explained)

ATLANTIC CENTRAL
But you would still have to build and wire the panel? That's the hard work?

not if your willing to use a graphics screen such as JMRI

you haven't explained the connections between the CTC and your layout

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Monday, September 26, 2022 8:37 AM

gregc

the topic is does DCC require less and simpler wiring? 

it certainly can, both in terms of # of wire as well as length of wire (as explained)

 

 
ATLANTIC CENTRAL
But you would still have to build and wire the panel? That's the hard work?

 

not if your willing to use a graphics screen such as JMRI

you haven't explained the connections between the CTC and your layout

 

And I would be happy to do that later, or with you directly off the forum, but right now I am rebuilding an 1885 porch.

Sheldon

    

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Posted by SeeYou190 on Monday, September 26, 2022 10:53 AM

The DCC layouts I have seen using signals have employed various optical sensors to get the job done.

It seemed pretty simple to me, though I do not know all the ins-and-outs.

-Kevin

Living the dream.

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Posted by gregc on Monday, September 26, 2022 12:03 PM

SeeYou190
The DCC layouts I have seen using signals have employed various optical sensors to get the job done.

It seemed pretty simple to me

as Sheldon suggests, signals indicate the occupancy of a block by any part of the train.   Even basic signaling systems will not only indicate STOP, but APPROACH if the next block is occupied.

but with dispatching or CTC, block occupancy must be communicated to the CTC machine (PC) and the dispatcher determines the aspect to indicate thru the CTC machine.

this communication between the CTC and signal could be a long set (red, green, yellow) wires or it could be in a packet of information sent of some serial communication path such as LocoNet to some stationary decoder or some other device (e.g. Arduino)

the CTC machine would also control nearby turnouts

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Monday, September 26, 2022 10:46 PM

gregc

the topic is does DCC require less and simpler wiring? 

it certainly can, both in terms of # of wire as well as length of wire (as explained)

 

 
ATLANTIC CENTRAL
But you would still have to build and wire the panel? That's the hard work?

 

not if your willing to use a graphics screen such as JMRI

you haven't explained the connections between the CTC and your layout

 

OK, did my share to preserve history today in the town of Havre de Grace.

First point - I can tell you as a former electrician who built industrial control panels, and as a project manager in that industry who did cost estimates, do you know how people in industry figure out how much labor it will take to build a hard wired control panel?

They count terminations - how many ends of a wire must I connect? Within the panel there is no labor concern about how much wire.

Yes, at some point in a complete industrial installation remote runs are measured in feet and standard labor rates gathered from experiance are used to estimate the cost of "pulling the wire", but then it has to be terminated.

So on the scale of building a model train layout, hooking up 20 pushbuttons is a bigger factor than how much wire is between the 20 pushbuttons and whatever they are connected to. Running cat5 wire is pretty easy.

BUT, my wiring does work to limit long runs to the fewest number of conductors.

Using wiring methods and circuits that have been used in industrial control for over 100 years now.

How does my non computerized CTC panel work?

Well, the logic is not anywhere near the panel. The logic is spread all over the layout in "nodes" as you would call them. 

CTC panels rely on three basic elements - detection, turnout position, permission.

Dispatchers see where trains are, they align routes, and they give permission. The automatic features of the turnout controls and the signal system do the rest.

My CTC panel will not use the traditional lever switches from the prototype - they take up too much space. While I like actual tactile buttons and switches, I do need to put a lot of info in about 12' wide x 16" tall control panel.

And, I prefer to streamline CTC a little due to our compressed distance and time in our model worlds.

And, also as a concession to our compressed time and space, I use lighted pushbutons with circuits that release previous settings when a new setting is selected.

Nearly all the signals on my layout are absolute signals, controlled by detection and CTC, protecting and directing traffic at the interlockings.

I do not model any permissive automatic block signals. Even on a layout of this size, the distances vs train lengths do not support it. A primary design goal is to run long trains, the distances between interlockings do not support the movement of more than one, or in a few cases two, trains in the same direction between any two given interlockings, so block signals between interlockings are only required in a few locations.

The dispatchers panel will contain cab assignment/permission buttons for the 15 primary control blocks - control blocks are not the same as signal blocks.

15 blocks x 6 cabs + 15 reset buttons = 105 buttons = 107 wires, grouped into cat5 cables that go out to the various nodes at each interlocking to assign primary blocks throttles and grant signal system "permission". That is only one cat5 cable from each primary control block node back to the dispatchers panel.

Those buttons are lighted to indicate selection but require no addtional wire because the control wire of the selected cab stays hot when selected and powers its own LED.

There will be about 60 separate route control circuits controling turnouts, 28 of which are for the hidden staging. That will require 62 wires, and again, those circuits support their own indicator LED's without additional wires.

The 15 primary blocks will report block occupancy and that will require 16 wires.

The 28 staging tracks will have separate detection reporting that will require 29 wires.

There will be a few other wires for some interlocks and other features.

All other logic and control is handled by relay panel nodes near the related interlocking and tower panels. 

Relay and control panels will be bench built. Once installed they get connected to each other and to nearby switch motors, track connections, signals and daisy chained to the next node to the east and west.

Detectors for nearby bocks are located on the relay panels - signal logic all happens right there and is daisy chained as needed from east and west, typically just 4 wires each way.

Relay panels typically contain two/four cab assignment circuit boards and detectors, six to twelve permission relays, and one relay for each turnout controlled by that tower panel. All depending on the complexity of the interlocking.

Tower panels will contain the same turnout route controls and cab permission controls as that section of the dispatchers panel - the dispatcher will be able to disable or inable tower panel control.

Trains that pass red over red signals will just stop, the power routing thru the interlocking leaves the track unpowered on routes not selected.

Pretty simple really. The same basic motor control circuit and some yes/no sequence logic for the signals, all from info available on the relay panels, just repeated as needed.

Some inductive detectors, LED signals, and Aristo wireless throttles.

Wait until I tell you how two switchers can operate opposite ends of the 8 track yard independently, only occasionally requiring any button pushing.......

All with no little brains in the trains and no computers under the layout.

So don't build this unless you really have an interest in old fashioned electronics like the railroad used for signals back in the 20's, 30, 40's, 50's, 60's - in fact, electronis that they are just now finally fully upgradings and replacing...... 

But understand, if you want to add signals, CTC and advance turnout route control to DCC, it will be complex and expensive - even if it does not take quite as many wires as this.

Sheldon 

 

 

    

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Posted by SeeYou190 on Monday, September 26, 2022 11:17 PM

The Dream House layout had a room dedicated to the CTC panel.

About six months into layout construction... FORGET THAT!

The room was only ever used for storage.

-Kevin

Living the dream.

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Posted by gregc on Tuesday, September 27, 2022 5:38 AM

ATLANTIC CENTRAL
But understand, if you want to add signals, CTC and advance turnout route control to DCC, it will be complex and expensive - even if it does not take quite as many wires as this.

route control is already done using JMRI.  no panels are needed because turnouts are controlled using the DCC controllers

how is it complex and how expensive?

we're adding circuits to control signals at the club.   we're using the PSX's built in block occupancy output to drive a small transistor circuit to control the signals that costs $3.

basic signal logic is trivial:

if block occupied  // PSX output
    display STOP
else
    display CLEAR

i'm planning on replacing that with an esp12 board that supports WiFi that will simplify the circuitry to control just a couple signals which will cost maybe $15.   WiFi allows the nodes to communicate with one another allowing APPROACH signals to blocks in a different node

if block occupied
    display STOP
else if next block occupied  // over WiFi
    display APPROACH
else
    display CLEAR

once the wire connections are correct, logic bugs and enhancements can be changed by plugging in a USB and reprogramming the processor. 

WiFi avoids stringing multiple wires between nodes or back to a dispatcher panel

as already mentioned, a graphical JMRI CTC panel can control turnouts and signals with locoNet and/or WiFi

yes, some of this is easy for me design because of my background, just as the wiring and relay logic is easier for you.

but i've helped modelers using Arduinos to do similar (e.g. control semaphores) and a generic program with predefined pin functions can be download by modelers so they can build a node

it's not that complex and it doesn't have to be expensive

 2861

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 6:32 AM

gregc

 

 
ATLANTIC CENTRAL
But understand, if you want to add signals, CTC and advance turnout route control to DCC, it will be complex and expensive - even if it does not take quite as many wires as this.

 

route control is already done using JMRI.  no panels are needed because turnouts are controlled using the DCC controllers

how is it complex and how expensive?

we're adding circuits to control signals at the club.   we're using the PSX's built in block occupancy output to drive a small transistor circuit to control the signals that costs $3.

basic signal logic is trivial:

if block occupied  // PSX output
    display STOP
else
    display CLEAR

i'm planning on replacing that with an esp12 board that supports WiFi that will simplify the circuitry to control just a couple signals which will cost maybe $15.   WiFi allows the nodes to communicate with one another allowing APPROACH signals to blocks in a different node

if block occupied
    display STOP
else if next block occupied  // over WiFi
    display APPROACH
else
    display CLEAR

once the wire connections are correct, logic bugs and enhancements can be changed by plugging in a USB and reprogramming the processor. 

WiFi avoids stringing multiple wires between nodes or back to a dispatcher panel

as already mentioned, a graphical JMRI CTC panel can control turnouts and signals with locoNet and/or WiFi

yes, some of this is easy for me design because of my background, just as the wiring and relay logic is easier for you.

but i've helped modelers using Arduinos to do similar (e.g. control semaphores) and a generic program with predefined pin functions can be download by modelers so they can build a node

it's not that complex and it doesn't have to be expensive

 2861

 

 

Greg, I understand, and even agree. But that was not always the case.

Assuming one is comfortable/willing to use computer screen interfaces and/or DCC handhelds/smart phones as the human interface.

I am not comfortable with those choices.

As I explained somewhere above, I have used Digitrax throttles to select turnout routes - that is a miserable process - of course for me the whole Digitrax throttle is a miserable experience. Why would I push 5 buttons when I can push one?

And again, many of these options were not available, or fully available, or fully developed 22 years ago when I needed a control system. You are coming at this from what is readily available and in many cases pretty new right now.

I'm not chainging this now just like I'm not replacing 50 years worth of rolling stock with all new high end RTR. Or, just like I am not replacing or rewiring 145 locomotives to get 5% more detail and DCC/sound. 

Again, I will fully concede that the cost of doing this stuff has come down, again, if you are willing to accept specific approaches.

You used a key phrase - "I am planning on replacing" - how long has the previous product been in use?

I can't participate in this hobby from that perspective - the perspective of constant replacement and upgrading.

I just want to the whole thing built one more time in my lifetime and to play with it. The electronics is not thewhole hobby for me - it is a means to an end.

I don't want to be in a club, I have helped enough others build their layouts. I do want to invite people to come to my house and play.

I have the space, the stuff, the extra money, and now am about to have plenty of time. But I will use what I have, because it was good enough 20 and 30 years ago, it is still good enough.

Sheldon  

    

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 6:40 AM

SeeYou190

The Dream House layout had a room dedicated to the CTC panel.

About six months into layout construction... FORGET THAT!

The room was only ever used for storage.

-Kevin

 

Kevin, I agree. I would NEVER have a CTC panel in a separate room or jammed in a corner. 

I hate all that prototype "extreme" operational realism stuff.

My dispatcher will have a commanding view of 2/3rds of the layout.

Sheldon

    

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 6:55 AM

Greg, one last thought.

No offense to anyone, but I would be willing to bet a pretty large percentage of those reading this discussion lack the knowledge to design and install my approach or your approach completely on their own.

And that speaks volumes about why so few layouts have CTC, signals or advanced route control.

Sheldon

    

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Posted by gregc on Tuesday, September 27, 2022 7:06 AM

ATLANTIC CENTRAL
You used a key phrase - "I am planning on replacing" - how long has the previous product been in use?

you've repeatedly described the "Sheldon Approach" for doing layout control.   but there are many ways to accomplishing that depending on needs and how the layout may already be wired.

the club had some signals in place and because i discovered that PSX circuit breakers had a block occupancy detector, started trying to get the signals to work.

to do so, i quickly put together a small transistor circuit to turn on LEDs to indicate STOP or CLEAR.   that worked and club members were very happy to see the signals working as well as providing some meaningful information when operating their trains during open houses

that simple $1 transistor circuit built on a solderless breadboard served it's purpose and is being replaced.   because of that experiment, we're cutting and splicing DCC track buses to make the blocks more suitable for signaling.   this includes replacing a DigiTrax PMM circuit breaker with spare PSXs supporting block detection

while i wouldn't replace existing electronics if it does what is needed, there's no reason not to try something simple and inexpensive as a stepping stone towards something more complete.

even if you have older electronics on your layout, there's no reason not to use newer less expensive stuff when expanding the layout while leaving the older stuff in place

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 7:27 AM

Again, proved my point. You are fixing and finishing something others did not know how to do. 

And I am still happy I don't have 145 decoders to configure........

Back to porch....

Sheldon

    

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Posted by gregc on Tuesday, September 27, 2022 7:37 AM

ATLANTIC CENTRAL
You are fixing and finishing something others did not know how to do. 

how does that demonstrate that DCC requires more wiring?

greg - Philadelphia & Reading / Reading

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 7:55 AM

Note to all, I did not start out trying or wanting to defend or describe my control system. 

I simply pointed out that hooking up feeder drops every 6 feet is a lot of connections and thereby a lot of work. For the 1000 or more feet of track on my new layout that would be over 600 connections.

The other thing I pointed out was that signaling, detection, and turnout control still have to wired up if you want those features.

That was my ONLY point.

Sheldon 

    

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Posted by richhotrain on Tuesday, September 27, 2022 8:16 AM

ATLANTIC CENTRAL

Greg, one last thought.

No offense to anyone, but I would be willing to bet a pretty large percentage of those reading this discussion lack the knowledge to design and install my approach or your approach completely on their own.

And that speaks volumes about why so few layouts have CTC, signals or advanced route control.

Sheldon

 

That may be true, but another possible explanation is that many, if not most, layouts are too small to justify the time and expense necessary to install CTC or advanced route control. My layout is probably large enough to implement these controls, and I am probably smart enough to learn how to design and install these controls if I weren't so lazy. The concept does sound cool.

Rich

Alton Junction

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 10:43 AM

gregc

 

 
ATLANTIC CENTRAL
You are fixing and finishing something others did not know how to do. 

 

how does that demonstrate that DCC requires more wiring?

 

 

I never said MORE.

Sheldon

    

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Posted by Overmod on Tuesday, September 27, 2022 11:49 AM

ATLANTIC CENTRAL
Assuming one is comfortable/willing to use computer screen interfaces and/or DCC handhelds/smart phones as the human interface. I am not comfortable with those choices.

With all due respect: this thread isn't about what you do or don't want, it's about what the OP does and doesn't want.  As he stated initially that he thinks DCC is the 'way of the future', any discussion of advanced non-DCC wiring schemes that 'he doesn't have the knowledge to build' is ridiculous, even if it weren't being repeated over and over and over.

Let the OP comment on whether he's comfortable with computer screen or phone interfaces, or would prefer something else.  Make the case for DC after he says what he does and doesn't find valuable.  I'd be surprised if you can convince him that DC ought to be his 'way to go', but convince HIM based on what HE values.  

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 1:51 PM

Overmod

 

 
ATLANTIC CENTRAL
Assuming one is comfortable/willing to use computer screen interfaces and/or DCC handhelds/smart phones as the human interface. I am not comfortable with those choices.

 

With all due respect: this thread isn't about what you do or don't want, it's about what the OP does and doesn't want.  As he stated initially that he thinks DCC is the 'way of the future', any discussion of advanced non-DCC wiring schemes that 'he doesn't have the knowledge to build' is ridiculous, even if it weren't being repeated over and over and over.

 

Let the OP comment on whether he's comfortable with computer screen or phone interfaces, or would prefer something else.  Make the case for DC after he says what he does and doesn't find valuable.  I'd be surprised if you can convince him that DC ought to be his 'way to go', but convince HIM based on what HE values.  

 

I already suggested the op and others go with DCC.

I just suggested the that op understand that the other features one might want still require wiring of one sort or another.

Sheldon

    

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Posted by doctorwayne on Tuesday, September 27, 2022 5:52 PM

ATLANTIC CENTRAL
No offense to anyone, but I would be willing to bet a pretty large percentage of those reading this discussion lack the knowledge to design and install my approach or your approach completely on their own.

I certainly can agree with you on that, Sheldon.

My DC layout is powered by just two wires, with no CTC, no semaphores or signals of any kind, and no multiple trains running at the same time...those things not only don't interest me, but are beyond my capabilities.
Of course, those two wires did require additional wiring so that I could control which tracks were live and which ones weren't.
I hadn't planned for any further wiring, but when I decided to add some electrically-powered turnout controls, to accommodate turnouts that were no longer reachable, more wiring was required.

While the layout is still not "done", I'm pretty sure the need for additional wiring will not be too onerous.

Wayne

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Posted by ATLANTIC CENTRAL on Tuesday, September 27, 2022 7:51 PM

OK, I will just go back to my first comment in my first post.

The every 6' buss wire feeder drop question. I don't think it is really necessary, BUT: 

All the DCC "experts" seem to say you need to do this, especially on larger layouts.

So if I apply the 6' feeder drop concept just to the double track mainline of my new layout, 420 feet of double track.

So 420' feet of buss wire, 2 #12 wires?

420' of double track x 2 = 820' track divided by 6' x two wires = 2 drops every 6 feet = 280 drops, each of which needs to be connected on each end = 560 connections that have to made. 

If each drop is 2' long x 280 drops = 560' of whatever size wire is recommended for that.

So now we are up to 1540' of whatever size wire, and 560 connections.

And we have not yet considered other trackage like my stub end staging which is another 250' of track that would require 25' of buss wire, 80 more drops which is another 160 connections.

Then there is the eight track, 25' long freight yard, three more staging yards, and the passenger terminal.......

How can anyone say that's not a lot of wiring?

I know that what I do is a lot of wiring.

And if you use powered switch machines you have to get those two or three wires from whatever controls them to the switch motor - I don't care if it is a solid state device or a toggle switch.

As I explained earlier, as a person with professional experiance building control panels that run machines, we counted connections as the primary measure of how much labor the control wiring would require to install.

Just because you don't have to know as much about what the wires are doing, it still takes the same amount of time to connect them.

How many of you buy some giszmo for your layouts to power turnout frogs? How many connections is that? I do that in DC as well, it is three more wires x 2 = 6 connections per turnout. In my case times about 120, yes a lot of wiring.

OK, you don't have to design, wire and implement a cab control system, yes that is a wiring savings.

A quick estimate suggests that the DCC buss connections described above for my layout are similar in number to the connections necessary for my push button cab control system using my custom circuit board panels. That's why it made sense for me to invest in those circuit boards, each circuit board saves 112 connections.

Again, I'm not suggesting anyone should follow my path, I have friend just getting started in the hobby, I told him to go DCC. 

But why all this minimizing of the required wiring infrastructure?

Sheldon 

    

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Posted by maxman on Tuesday, September 27, 2022 8:20 PM

jjdamnit
Hello All, York1 Any over/under bets on how many pages this will go? Well, you've expanded the discussion to the second page..

Ahem.  I wish folks would just answer the OP's questions instead of rambling on about non-related matter.

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Posted by ATLANTIC CENTRAL on Wednesday, September 28, 2022 6:48 AM

richhotrain

 

 
ATLANTIC CENTRAL

Greg, one last thought.

No offense to anyone, but I would be willing to bet a pretty large percentage of those reading this discussion lack the knowledge to design and install my approach or your approach completely on their own.

And that speaks volumes about why so few layouts have CTC, signals or advanced route control.

Sheldon

 

 

 

That may be true, but another possible explanation is that many, if not most, layouts are too small to justify the time and expense necessary to install CTC or advanced route control. My layout is probably large enough to implement these controls, and I am probably smart enough to learn how to design and install these controls if I weren't so lazy. The concept does sound cool.

 

Rich

 

You are correct, layout size and design has a lot to do with the practical application of signaling or CTC.

The mistake, in my opinion, that many make is trying to model every nuance of the prototype, especially a specific railroad or location. Since our distances are compressed, this seldom works or has any benefit to operation or realistic appearance.

Your layout is large enough for some basic interlocking signals that would add a lot of visual interest and may aid in operation should you ever have a guest operator or two.

Most of it is stuff anyone can learn, if they want to. Many who are computer savvy will be more comfortable with Greg's high tech approach, others may do better with older methods where you can look at a diagram and understand why the light comes on.

In any case, I feel it is best to streamline signal systems a bit from actual prototype practice, which can get pretty complex.

Sheldon

    

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