Layout wiring

I will not claim to be one of the smart people and simply ask do you have an idea of where the TIU/transformer will be located? That will dictate the longest wire runs.

Good morning , thanks for answering.

The transformer and TIU are located center of the yard along the lower wall in the drawing. The longest wire run is between 36-40' in both directions.

I just want to make sure I put blocks where I should for best results. Also I want to be able to turn off 2 of the sidings in the yard.

Mike, I'd like to be able to help you, but I have no experience with DCS wiring.   Hopefully, this post will bump up your topic.

I'm guessing you already know that with DCS that there's more to consider compared to wiring other command control systems, and it's why you're asking for help.  The DCS Companion Book by Barry Broskowitz is often mentioned as the main go to resource.

For this topic to get more attention, you might consider Editing the Topic Title to indicate that you're Looking for Help with DCS Layout wiring.  I hope this is at least somewhat helpful.

'morning Mike,

Glad you chose that location, seemed centrally located to me. I assume your drawing is scaled and so I don't see any reason for 36-40 feet wire runs. I see two runs, one up to the siding in front and one to the adjacent track, that could be 17 feet or so.

It starts with how you configure your track into isolated blocks. I believe I read once on the Ross website that switches often make a good place for isolation. For example, if you consider the large loop on the right side bounded by two switches. That loop could be configured as two blocks. Your wiring to reach them only has to get as far as the track coming out of the first switch closest to power. It is possible to put the single DCS drop at either end or in the middle of a block, you just have to honor the recommendation for number of joints the signal will pass through in each block. It is number of track joints, not length of the block, that is important.

I also want sidings that can be powered up and down so I've been studying the different approaches to the watchdog issue. An easy way to handle the watchdog issue with sidings is to dedicate a TIU channel (if possible) to the sidings. Then you want to switch power to those sidings before the TIU channel. The TIU sends watchdogs for a short time when a channel is first powered.  I have not tried this method so I can't comment on how DCS behaves. I don't know that this will scale if you have more than a few sidings, but there are more sophisticated ways if this doesn't do it for you.

Morning Dan, thanks for getting back to me. I took a couple photos to show where the Z4000 and TIU are located now. I am redoing my layout to the new plan and just want to make sure I do everything to get the best out of it.

Mikesee

The opening in your benchwork can also define a block boundary since the tracks need to be cut. A block on the right hand side could be extended through the switch and power the right side, the left side is obviously picked up from the left side block. Seems like most of your wiring runs can be limited to the back half. That one short piece of track on the siding that extends beyond the opening may be a little tricky to run wires to because it needs to be on the same block as the rest of the siding for the watchdog scheme, or you could leave that piece unpowered if you don't think you would run an engine that far down that siding.

Mike,

While I'm no electrical wizard, other than your two sidings being cut from layout operating power, I'm not sure why you think you need "blocks?"  Seems to me, you could start your star wiring pattern with terminal strip under the layout right next to the transformer / TIU, and then run a series of multiple length wires from that terminal to well spaced locations around the layout where you make track connections.  The longest wires would have to make the run all the way from your start location by the yard to the track on the opposite side of your center opening.  Do you have, and, have you looked at, Barry's DCS book?

I've also noted a slight operational problem with your track plan.  Once a train starts running counter-clockwise on your yellow loop, there is no way to reverse it without traversing the green loop which has 2 reversing loops included.  However, if you include another connection from the topside of the yellow loop on the left into your yard area, now your yellow loop will also have 2 (instead of 1) reversing loops, although one will be a little convoluted.  This would allow trains to reverse directions on both the yellow and green loops without interfering with each other.

Chuck

@PRR1950 posted:

While I'm no electrical wizard, other than your two sidings being cut from layout operating power, I'm not sure why you think you need "blocks?"

He needs blocks because one TIU channel is not going to provide the power to all that remaining track and still maintain decent DCS signal levels.

Hi Chuck, thanks for responding, as for the blocks from what I read its the best way to share the power, also my layout has limited blocks and I have found if I put blocks in and document where they are it makes it easier for trouble shooting electrical problems most of the time.

I am just not good enough with electrical as some of the folks here will tell you I am a little slow when it comes to that. That's why I am asking help wiring this redo of my layout so I can get the best of the equipment I have. I hear people using all 4 channels of there Z4000 to power track and I only use 1& 2. I haven't figured out how to use the 2 center ones yet.

I do have Barry's DCS Book but sometimes reading that I still get lost, sometimes I have to read things 3 or 4 times before I get it.

In closing lets just say I am not the brightest bulb around! LOL

@mike g. posted:

I hear people using all 4 channels of there Z4000 to power track and I only use 1& 2. I haven't figured out how to use the 2 center ones yet.

It would be a neat trick to use all four channels of the Z-4000, it only has two channels and a low power accessory output!

@gunrunnerjohn posted:

It would be a neat trick to use all four channels of the Z-4000, it only has two channels and a low power accessory output!

See I said I was SLOW! LOL

"The longest wires would have to make the run all the way from your start location by the yard to the track on the opposite side of your center opening. "

Not really, he just needs to connect a pair of wires to the part of that track closest to the TIU, on both sides of the opening. The track will conduct the signal the rest of the way around. Those locations are just past the switch on either end of the layout that lead to the opening.

I would not wire DCS without using blocks.

Hi Chuck, I took what you said and added a switch to the yard and Main line. It takes a little doing, but now I can turn the train around.

One of the top things on my list was the ability to be able to turn trains around and run in either direction.  As a rule, I have a "standard" direction to run, but sometimes the way they come from the yards or turntable, it's nice to turn them around.

Looks good, Mike.

@PRR1950 posted:

Looks good, Mike.

Thanks!

@gunrunnerjohn posted:

One of the top things on my list was the ability to be able to turn trains around and run in either direction.  As a rule, I have a "standard" direction to run, but sometimes the way they come from the yards or turntable, it's nice to turn them around.

I agree, part of the new plan was to add excitement and also so I could run trains while I was working on other projects at the same time!

I use AnyRail, does Scarm have electrical isolators?  You could create a copy of your plan and use it to mark up blocks and also where the connection would be for each block.

Hi Dan, I don't know. I would have to check.

@turkey_hollow_rr posted:

I use AnyRail, does Scarm have electrical isolators?  You could create a copy of your plan and use it to mark up blocks and also where the connection would be for each block.

I dont see any! Sorry

There are a few ways in SCARM one could mark blocks and such:

1) Add Text (CTRL + t ) then left Click where you want to place the text then type

2) Draw a geometric shape(s) using the Figures Library

3) Use color coded track sections to denote connections and/or blocks and Power Districts.

I believe I see what @PRR1950 was referring to, I'm having a little trouble seeing track joints. The longest run is up to that upper level siding. To avoid the "5 or 6 joint rule" the next two longest runs are to the middle of the front curves on the upper level. On both sides, the block would run from the opening, straight through the first set of switches (isolate the turnouts) back around to the next switch on either side. On the left that is the switch were your lower track meets the upper level, on the right it's the first switch facing the front. It looks like you can wire the front half of the lower section in similar locations. There is a block on the upper level on the right side that completes the loopback. So there's 5 blocks/connections and the front half is wired.

Is your opening hinged? If so you can wire it to the tracks on the hinge side with a terminal strip connection, like a jumper wire, and piggy back on the adjacent blocks. Not nearly as noisy as a track joint.

Morning Dan, in this screen shot I put the elevation blocks in. everywhere there is a small square is a track joint. I hope this helps.

Mike,

My post is only looking at the upper track and the incline from the opening to the upper level.

I loaded this as an image and attempted to mark it up as close to a joint as I can get. The red lines are isolation points, the black X's are drop locations for each block. I don't know any particulars about the opening so I just put a red line down the middle of it.

I also place a TIU label approximately where I think yours is located assuming you will have terminal strips close by. Your runs will be from this area to each black X.

WOW Dan thank you so much! Looks like that should be easy enough to get it done!

Dan, that’s a nice job!

Thanks for your kindness, Mark and Mike, and thanks also for the opportunity to share some of what I've learned through OGR. Fortunately, Mike's layout can be carved up fairly simply or I would probably be over my head. Mike's selection of long pieces also helps to keep from getting stupidly small blocks.

The lower level track on the right side can be similarly divided back to the beginning of the yard. Sectional track in curves usually need a drop right in the middle so the curve on the lower left is pretty much defined.

I'm guessing that will be an engine shed at the end of the wye on the lower left, and will those tracks also be switched on and off? Looks like that branch can be isolated at the turnout leading to the wye.

That will get things narrowed down to the yard. I'll get something marked up later this afternoon.

Sorry, but personally, I disagree with Dan's approach; way too many segments for just one long loop.  I would just treat each loop as a separate operation by cutting the rising segment just past the yellow switch where the rise starts and then add another cut at the green switch where the rise meets the upper level loop.  Now, your 2 loops can be run independently, as can the rising segment.  For any sidings you want to be able to shut down, just cut that track right after the switch.  (For track planning purposes, you might add a double-ended siding along the rising segment so trains can go up or down at the same time.)

In his green loop suggestions, Dan seems to be putting cuts into the reversing loops like formerly needed in 2-rail DC powering (exclusive of DCC or other newer innovations).  Those are not needed in 3-rail operation.

If you're worried that the loops are still too "big," just add more power feeds around each loop off of the same TIU power for that loop.

Chuck

By all means Chuck!  There's a right way, a wrong way, and there's my way.

This is how I wired my layout. I'm simply counting track connections. I've never used DCC, but I understand the DCS technology and the reasons behind the recommendations for using blocks. If the number of blocks is troubling the option to solder across track joints is always there.

You are welcome to wire your layout how you wish but I believe some of your recommendations are just not correct for DCS.

Mike,

Here's my interpretation for the lower level. There is a red smudge on the two switches you recently added so ignore that. The isolation is between those two switches where they connect the two yard tracks, and the upper switch is part of the block from the curve on the left to switch all the way to the right. The yard wiring I suggest will work but may not be what you want for operating.

@turkey_hollow_rr posted:

Mike,

Here's my interpretation for the lower level. There is a red smudge on the two switches you recently added so ignore that. The isolation is between those two switches where they connect the two yard tracks, and the upper switch is part of the block from the curve on the left to switch all the way to the right. The yard wiring I suggest will work but may not be what you want for operating.

Hi Dan, thank you very much! I have more drops then what you so already on my layout I am changing to the new one. So that is not going to be a problem for me. I had more interest where to put the block isolations. As far as I can tell it looks like it will work very well!

My pleasure, Mike. This wiring should support achieving high DCS signal quality. Please post back with details of how you connect the TIU channels to the four amp channels, and how you finished up. I doubt I'll ever use more than two channels, maybe a third for conventional. I'm not familiar with the ZW either.

I'm no expert, I only play on on the forum, but my early instructions were for DCS RRs to isolate all rails of each block and directly feed non bundled  twisted star wiring with two single wires directly from power source to each block attaching to just one end of it.  Not in the middle.

Do those instructions from a long time ago still hold true?

I read so many comments of folks who do not use that pattern yet claim strong readings??  Perhaps other variables at play??

Tom I have no idea, I know my current layout is just a standard wiring with lots of drops and I have no problem with signals! Mostly 10's all the way around.

Hi Tom,

I am a late adapter of DCS having bought into the equipment in the last 3 years so I'm unfamiliar with the recommendation to also isolate the ground rails. Seems like it would work, I think it is maybe extra work for little gain as the signal will follow the shortest path, for the most part. It could be part of a solution in some cases.

The main goal is to avoid any duplication (reflections) of the DCS packets on the power rail so in theory we isolate the track at length short of where signal propagation might result in the ghosting of packets, and degrade signal integrity. I believe this is why the DSC Companion recommends blocks no longer that 100 feet.

But we also have to contend with electrically noisy track connections which negatively impact packet detection by increasing the noise, so DSC Companion recommends 5 or 6 track joints as a limit for passing the DSC signal through. The DCS companion also recommends keeping blocks to not more than 12 track sections. My interpretation of that spec is that it applies in two directions from the source, the power rail drop in the block.

If there is a terminal strip on the output of the TIU channel, as it seems most of us do, then that is a split in the signal that affects every block attached to it. That seems like the nucleus of the star to me.

These are my thoughts as to how I follow the DCS recommendations. It is a conservative approach. I will not claim this is the only way to get things to work.

BTW, I love seeing pictures of your work.

Keep in mind that DCS equates packet acknowledgement counts to signal strength. I think 80 packets out of 100 is a 10(?).

Actually, I believe that 10 out of 10 is a 10.  If all of the queries don't get a return packet, the signal strength is reported as a percentage of the successful packets.

I'm sure you know the correct numbers, John. Thanks for keeping me straight. I always have a hard time finding that in the Companion.

I'm also correcting my thoughts on the reason for the 100 feet is packet propagation delay.

Well, not to argue the point since it's kind of academic, but I did find this in the Companion under Wiring Considerations, DCS signal strength.

Paraphrasing,

"87-100 packets equates to a DCS signal strength of 10, 80-86 equates to a 9, and so on."

and

"nearly all DCS commands will operate just fine when the DCS signal strength is 7 or higher"

This actually shows that it is robust and why it works when it seems like it shouldn't.