Topics

Modular DCC Wiring

bmrailroad <bmrailroad@...>
 

I am a relative newbie to model railroading and am in the process of designing and building my first model railroad layout. I decided to make it a modular layout due to space requirements and the desire to bring it to local train shows on my own and with local model railroad clubs. I have purchased a Digitrax Zephyr to control my layout. On my modules I will use RJ12 (6 pin phone/data) jacks to connect the DCC bus wire. In my area there are several model railroad clubs with which I would like to participate. Each uses a different DCC system including Digitrax, Lenz, and NCE. As I understand it, Lenz and NCE use an RJ45 (Cat 5e) connector and wire for their DCC bus.

I understand you can not use both systems at the same time. However, is it possible to have two different bus wires and jacks on a single module, so that it can be used with either clubs layout using different DCC systems?

Home Depot sells an outlet cover with holes for two jacks. The face plate allows you to clip in whichever port you need. If it is possible to wire a module for both DCC systems, I would put a RJ12 in one and an RJ45 in the other.

Let me know your thoughts on this idea. I am very excited to get started with construction of my modules, and welcome any recomendations from fellow model railroaders.

Thanks,
Alan D. Smith
BM Railroad
Wallingford, CT

John Roth
 

Alan -

MRC uses an 8-wire RJ45 bus. NCE uses 6-wire RJ12.

You could use 8-wire cabling and jack it as you describe. Or, you could just use 8-wire and RJ45. The RJ12's will plug into an RJ45. Doing so could accelerate wear on the 1/8 contacts in the RJ45.

Unless you're certain that you have an 8-wire group near you that you want to run with, it might make more sense to just wire for RJ12.

My module group runs MRC/RJ45/Cat5. There is another group south of us building identical modules (w/RJ45/Cat5 command bus wiring) but they are running 6-wire NCE. Our modules have run with theirs using their NCE DCC. It all works.

-John

--- In WiringForDCC@..., "bmrailroad" <bmrailroad@...> wrote:

I am a relative newbie to model railroading and am in the process of designing and building my first model railroad layout. I decided to make it a modular layout due to space requirements and the desire to bring it to local train shows on my own and with local model railroad clubs. I have purchased a Digitrax Zephyr to control my layout. On my modules I will use RJ12 (6 pin phone/data) jacks to connect the DCC bus wire. In my area there are several model railroad clubs with which I would like to participate. Each uses a different DCC system including Digitrax, Lenz, and NCE. As I understand it, Lenz and NCE use an RJ45 (Cat 5e) connector and wire for their DCC bus.

I understand you can not use both systems at the same time. However, is it possible to have two different bus wires and jacks on a single module, so that it can be used with either clubs layout using different DCC systems?

Home Depot sells an outlet cover with holes for two jacks. The face plate allows you to clip in whichever port you need. If it is possible to wire a module for both DCC systems, I would put a RJ12 in one and an RJ45 in the other.

Let me know your thoughts on this idea. I am very excited to get started with construction of my modules, and welcome any recomendations from fellow model railroaders.

Thanks,
Alan D. Smith
BM Railroad
Wallingford, CT

Doug Stuard <dstuard@...>
 

Perhaps more important than the throttle bus wiring would be the module standards (track interface, track bus connectors, etc.) HO-trak, NTRAK, BendTrak, Free-mo, etc. all use different standards. The DCC interface may be the least of your concerns if you want to run with a variety of groups.

Doug Staurd

--- In WiringForDCC@..., "kewlbrew" <kewl_brew@...> wrote:

Alan -

MRC uses an 8-wire RJ45 bus. NCE uses 6-wire RJ12.

You could use 8-wire cabling and jack it as you describe. Or, you could just use 8-wire and RJ45. The RJ12's will plug into an RJ45. Doing so could accelerate wear on the 1/8 contacts in the RJ45.

Unless you're certain that you have an 8-wire group near you that you want to run with, it might make more sense to just wire for RJ12.

My module group runs MRC/RJ45/Cat5. There is another group south of us building identical modules (w/RJ45/Cat5 command bus wiring) but they are running 6-wire NCE. Our modules have run with theirs using their NCE DCC. It all works.

-John

--- In WiringForDCC@..., "bmrailroad" <bmrailroad@> wrote:

I am a relative newbie to model railroading and am in the process of designing and building my first model railroad layout. I decided to make it a modular layout due to space requirements and the desire to bring it to local train shows on my own and with local model railroad clubs. I have purchased a Digitrax Zephyr to control my layout. On my modules I will use RJ12 (6 pin phone/data) jacks to connect the DCC bus wire. In my area there are several model railroad clubs with which I would like to participate. Each uses a different DCC system including Digitrax, Lenz, and NCE. As I understand it, Lenz and NCE use an RJ45 (Cat 5e) connector and wire for their DCC bus.

I understand you can not use both systems at the same time. However, is it possible to have two different bus wires and jacks on a single module, so that it can be used with either clubs layout using different DCC systems?

Home Depot sells an outlet cover with holes for two jacks. The face plate allows you to clip in whichever port you need. If it is possible to wire a module for both DCC systems, I would put a RJ12 in one and an RJ45 in the other.

Let me know your thoughts on this idea. I am very excited to get started with construction of my modules, and welcome any recomendations from fellow model railroaders.

Thanks,
Alan D. Smith
BM Railroad
Wallingford, CT

Glenn
 

I see a problem with using one jack for two systems. Is the wiring sequence
the same for both systems?

I.e. if brand RJ45 uses pins 1&2 for the loco control and brand RJ12 also
uses pins 1&2 for loco control, when you plug a brand RJ12 plug into a brand
RJ45 jack, the RJ12 pin one will contact pin 2 of the RJ45 and pin 2 of the
RJ12 will contact pin 3 of the RJ45.

That locking tab on the plugs centers the plug in the jack so the pins 1-6
of the RJ12 will contact pins 2-7 of the RJ45.

I agree with Doug, module standards are more important than the DCC
interface. Besides, when connected to other modules that interface will
propagate DCC commands over to your module whether or not you have a
auxiliary jack on your module or not.

I would inquire at the various groups what the requirements are for the DCC
interface. You may not be required to have a jack installed.

You will not be connecting to the track buss; you will be connecting to the
DCC control base unit. On my antiquated DCC system, the auxiliary jacks are
connected to the command station not the track buss. You may have to decide
which group to belong to or wire your module for all groups. Assuredly, you
will not be able to use one set of wires for all systems.

I have not read up on all systems, I do know the NMRA has set standards for
decoders, but the rest is left up to the individual manufactures. Even if
two systems us an RJ-?? Connector there is no guarantee both use the same
wiring sequence at the connectors. One could use pins 1&2 for power while
another may use 4&5.

-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of kewlbrew
Sent: Friday, April 02, 2010 18:17
To: WiringForDCC@...
Subject: [WiringForDCC] Re: Modular DCC Wiring

Alan -

MRC uses an 8-wire RJ45 bus. NCE uses 6-wire RJ12.

You could use 8-wire cabling and jack it as you describe. Or, you could
just use 8-wire and RJ45. The RJ12's will plug into an RJ45. Doing so
could accelerate wear on the 1/8 contacts in the RJ45.

Unless you're certain that you have an 8-wire group near you that you want
to run with, it might make more sense to just wire for RJ12.

My module group runs MRC/RJ45/Cat5. There is another group south of us
building identical modules (w/RJ45/Cat5 command bus wiring) but they are
running 6-wire NCE. Our modules have run with theirs using their NCE DCC.
It all works.

-John

Doug Stuard <dstuard@...>
 

If the DCC wiring is entirely passive (i.e., no UP-5 panels, accessory deoders, etc.), a pin 1-pin 1 wired RJ45 8 wire scheme would work in providing connection from one end of module to another. The problem comes when connecting this bus to throttles, decoders and command stations. So long as in any given setup only one family of devices (NCE, Digitrax, etc.) is used, and they are not permanently connected to the bus, there should be no problem (just as if the same extension cord is used for a lamp, then for a radio, then for a toaster).

It is difficult to be all things to all systems however.

Doug Stuard

--- In WiringForDCC@..., "Glenn" <ghazel@...> wrote:

I see a problem with using one jack for two systems. Is the wiring sequence
the same for both systems?

I.e. if brand RJ45 uses pins 1&2 for the loco control and brand RJ12 also
uses pins 1&2 for loco control, when you plug a brand RJ12 plug into a brand
RJ45 jack, the RJ12 pin one will contact pin 2 of the RJ45 and pin 2 of the
RJ12 will contact pin 3 of the RJ45.

That locking tab on the plugs centers the plug in the jack so the pins 1-6
of the RJ12 will contact pins 2-7 of the RJ45.

I agree with Doug, module standards are more important than the DCC
interface. Besides, when connected to other modules that interface will
propagate DCC commands over to your module whether or not you have a
auxiliary jack on your module or not.

I would inquire at the various groups what the requirements are for the DCC
interface. You may not be required to have a jack installed.

You will not be connecting to the track buss; you will be connecting to the
DCC control base unit. On my antiquated DCC system, the auxiliary jacks are
connected to the command station not the track buss. You may have to decide
which group to belong to or wire your module for all groups. Assuredly, you
will not be able to use one set of wires for all systems.

I have not read up on all systems, I do know the NMRA has set standards for
decoders, but the rest is left up to the individual manufactures. Even if
two systems us an RJ-?? Connector there is no guarantee both use the same
wiring sequence at the connectors. One could use pins 1&2 for power while
another may use 4&5.



-----Original Message-----
From: WiringForDCC@... [mailto:WiringForDCC@...] On
Behalf Of kewlbrew
Sent: Friday, April 02, 2010 18:17
To: WiringForDCC@...
Subject: [WiringForDCC] Re: Modular DCC Wiring

Alan -

MRC uses an 8-wire RJ45 bus. NCE uses 6-wire RJ12.

You could use 8-wire cabling and jack it as you describe. Or, you could
just use 8-wire and RJ45. The RJ12's will plug into an RJ45. Doing so
could accelerate wear on the 1/8 contacts in the RJ45.

Unless you're certain that you have an 8-wire group near you that you want
to run with, it might make more sense to just wire for RJ12.

My module group runs MRC/RJ45/Cat5. There is another group south of us
building identical modules (w/RJ45/Cat5 command bus wiring) but they are
running 6-wire NCE. Our modules have run with theirs using their NCE DCC.
It all works.

-John