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!

What is up with all the DCC pin types 8, 9, 21, now 22 etc

11446 views
8 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2006
  • From: west coast
  • 7,654 posts
What is up with all the DCC pin types 8, 9, 21, now 22 etc
Posted by rrebell on Tuesday, September 22, 2015 10:32 AM

The title sums it up, I thought DCC was sopposed to have standards but it seems that it is breaking up into different camps. Are there adapters out there for the different types? Thats all one needs, is to add more stuff that takes up room in the smaller scales.

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Tuesday, September 22, 2015 10:52 AM

rrebell

The title sums it up, I thought DCC was sopposed to have standards but it seems that it is breaking up into different camps. Are there adapters out there for the different types? Thats all one needs, is to add more stuff that takes up room in the smaller scales.

 

Not a big deal. Your version of reality is different than what really exist. Check the different DCC manufacturers.

DCC is evolving even as we speak.

There are at least six different ways of controlling model trains using digital.

DCS, similar to DCC is one of them.

Bluetooth using a smartphone is probably the newest.

Go with what exist.

Look at how complicated motor vehicles have become.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    September 2003
  • 10,582 posts
Posted by mlehman on Tuesday, September 22, 2015 12:03 PM

22 pins? That's a new one, I guess. The main thing with the 21-pin decoders is that you have a plug and play decoder that can drive multiple outputs. That way, things like ditch, cab, and numberboard lights can all be handled without extra wiring. There's also plug-in support for sound.

The basics of what's inside hasn't changed. The extra pins just add reliability to the flexibility already built into the decoder.

You're right that this is introducing some issues of standardization not currently defined. More about this here: https://sites.google.com/site/markgurries/home/decoders/decoder-plugs-sockets/21-pin-plug-issues

Not everyone agrees on what pin does what. It needs to be sorted out soon IMO.

It's sure nice to not have to fight all those wires into the shell, however, hoping once done they still all work as intended. That is progress, despite some minir issues cropping up.

Mike Lehman

Urbana, IL

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, September 22, 2015 12:27 PM

 Part of the reason for newer connectors is that they are smaller. The 21 pin connector takes up far less space than the 8 pin. The original 6 pin was to fit in smaller N scale locos, but that is a relatively huge connector as well.

 The 21 pin allows a very small decoder to be used even for larger scales that need higher current funtion outputs - some of the output are actually logic level, which means they need supporting circuitry to handle the current load - which goes on the 21 pin motherboard in the loco. Look at Loksound decoders - the Select Direct is pretty much just a Select Micro mounted on an Atlas/Athearn format motherboard.

 The only screw up in all this is the NMRA defining the 21 pin conenctions differently than the already in use european standard - and it's mostly ignored, as the OEMs now using Loksound for sound are using Loksound's motherboard. TCS followed the NMRA draft for the 21 pin connector and thus only 4 functions work even on a 6 function decoder.

 For existing locos - frankly, who cares about the pins. 99% of the time I remove any factory electronics and hard wire the decoder. That way I know it will work, that the red and black are connected to the wheels, the orange and grey are connected to the motor. Nothing in between to possible be messed up. My locos only ever have headlights, I model pre-ditch lights and they never had extra beacons or warning lights, so a decoder with a 9 pin plug to a plain wiring harness is all I ever need.

 Outside of the teething pains with the 21MTC connector, they actually are all standard. AN 8 pin decoder has the same pinout as any other 8 pin decoder. Same with the 9 pin JST connectors. ANd the 21MTC will be too.

 ANother factor driving the different conenctors - look at most sound decoders, they end up with two connectors to handle the track power, motor power, functions, speaker, and capacitor. 21MTC gets that all in one connector.

                             --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Tuesday, September 22, 2015 12:41 PM

The 21 pin decoder is based on a plug/socket that has an array of 2 x 11.  That is 22.  One is not used, for insertion/polarity reasons.  Thus 22 backs down to 21.

 

I poked around on the subject a bit awhile ago.  And forgot most of it, I fear.

 

BUT.

 

I came away with a high opinion of the 21 pin concept.  I like how Loksound decoders sound/work, and am planning on installing a couple in two switchers I'm building.  I'm going to have sound.  And a capacitor.  And as many lights as I want.  And I will DEFINITELY use the 21 pin versions.  

Like the OP, I'm not at all interested in cramming adapters into my models.  Nor am I interested in the wired-plug in decoders that are common now.  I want pins on my decoder that plug into a socket on the model--no wires!  Interestingly, that appears to be how the new re-issue of Walthers' SW1 is designed--there's only room enough for a (in this case, 8 pin) direct plug decoder--no wires.  Hooray!

 

 

Ed

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Tuesday, September 22, 2015 12:48 PM

For what it’s worth, I standardized on the original 8 pin socket.
 
  
 
I use pin 3 for decoder function 3 to operate a single accessory function in my locomotives.  In my snail it turns on and off the rotating blade in the snow blower it pushes, in my E7B camera pusher it turns on and off the camera in the E7A, in locomotives with classification lights it turns them on and off.  My era is before ditch lights but it could be used for that too.
 
For my use the 8 pin socket is all I need and it keeps everything standard and easily interchangeable.
 
 
Mel
 
 
Modeling the early to mid 1950s SP in HO scale since 1951
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
  • Member since
    July 2006
  • From: west coast
  • 7,654 posts
Posted by rrebell on Tuesday, September 22, 2015 1:10 PM

And it seems there is even more confusing stuff coming out of new plus plugs. The 8 pin I like because it is easy to convert to dead rail for my 1930's era stuff.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, September 22, 2015 2:59 PM

 The 9 pin is pretty much the minimal plug for modern modeling - it allows 4 functions, so you get front and rear lights plus ditch lights. Anything less, and you are soldering wires to the decoder and making it fixed in place.

 Dead rail companies will have to step up and provide a 21MTC version of the receivers, since at least Intermountain, Atlas, and Bowser are using it now. Or it will help those types of DRS that still use a standard DCC decoder in the loco.

 The proble with the old standard 8 pin plug is that there are now decoders smaller than just the 8 pin socket that gets installed in the loco. Z height - the height of the socket on the loco plus the plug on the decoder or wire harness, is relatively huge. The 21MTC is a huge benefit for smaller locos - more connections yet significantly smaller than the previous options. The less space wasted by the plug system, the more space for a better speaker and enclosure for sound. It's hard to get plain wires to take up less space than the 21MTC, at least if you are trying to strip and solder those wires yourself.

                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July 2006
  • From: west coast
  • 7,654 posts
Posted by rrebell on Tuesday, September 22, 2015 4:17 PM

Sound will be in the future for us. Dead rail will be coming on strong due to Bachman entering the fray with their transition Bluetooth setup. For those doubters, remember when On30 was almost non existant untill Bachmann got involved.

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

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!