NRM Article - DCC for beginners (Part 4 now up)

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Re: DCC for beginners (Part 3 now up)

Postby pete12345 » Sun May 11, 2008 8:55 pm

Sorry, I don't have any pictures of my own installations (I tend to get carried away and forget to take any pictures :P ) but there are some excellent pictorial guides on Steve Jones' website

He seems to have fitted a decoder to every basic type of loco, and you can get some inspiration from there.


EDIT: Post 1111 :lol:
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Re: DCC for beginners (Part 3 now up)

Postby santene » Sun May 11, 2008 10:00 pm

that websites amazing :D thanks
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Re: DCC for beginners (Part 3 now up)

Postby leviathan1949 » Wed May 14, 2008 7:57 pm

An excellent thread Pete.

As easilyconfused mentioned earlier for anybody that wants to TALK DCC with the UKTS Team, pop along to any of the exhibitions where we take the DCC Workshop and we will gladly answer any questions. We are at the Leytonstone Exhibition this Saturday.(17th May).

Without imposing on Petes precious time, for those wanting instructions for fitting decoders in to specific locos then Google for your particular loco and in most cases you will find a site somewhere that has done it before and documented it.

Dapol have a few on their own site under the DCC menu option.
Bromsgrove Models also has a large number of links to various sites explaining individual installations.

There are NO hard and fast rules for decoder installations, with manufacturers changing designs very often, the instructions can only be serious guidelines at best.
As a simple example one guy I know has a ZIMO system and wants to fit a ZIMO MX64H into his loco. He also wants a Loksound sound chip in there as well. Given that the Loksound has traction control and full light functions AS WELL as the sound, you might ask why does he want the ZIMO chip as well. Answer because he prefers the traction control that the ZIMO has but wants the sound capability of the Loksound.
And Yes, it can be done, if there is physically room for the two decoders in the loco.

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Re: DCC for beginners (Part 4 now up)

Postby pete12345 » Fri May 23, 2008 11:56 am

Part 4: Decoder programming

As requested, here’s a how-to on programming decoder CVs
The first thing we need to install, before thinking about programming the decoder, is the programming track. This is a low-powered section of track we use when configuring the decoder. In the event of an incorrect decoder installation, this also does not have enough power to destroy the decoder.

Most command stations will have a separate output for the programming track. For Lenz, the convention is terminals P and Q. The simplest way is to connect these to a spare piece of track, and you’re away. However, it avoids having to pick up the loco if you have a siding which can be switched between the main track or the programming output, the wiring for which is shown below.

This way, you can change the loco’s settings by just driving on to the siding and throwing the switch.

Ok, now we get to the programming itself. I’ll be referring to the procedures with my Lenz Compact, but the principle is exactly the same on all systems. Use your controller’s handbook in conjunction with these instructions.

There are two types of decoder CVs: simple ones which take a decimal value, such as the decoder address, maximum speed etc, and complex ones which use a binary system to turn settings on or off. First let’s cover the simple ones. The one everyone will need to set is the loco address; CV1.

Right, with the loco positioned on the programming track, we enter program mode.

· On my controller, programming mode is accessed through the menu.
· Select CV1 and confirm.
· Confirm again to read back the current setting (with a new loco, the address should read back as ‘3’
· Change the address with the +/- keys and confirm again to set the address.
· The display should now read the new setting.

That’s it! Wasn’t that simple? Most of the basic CVs can be programmed in this way. Examples are acceleration delay, braking delay, maximum speed, starting voltage. Even using these, you can set up most of the characteristics of each loco.

A quick note on the Lenz Compact:

The instruction manual for the Compact will tell you that you can only write five CVs, which are accessed through ‘register’s. However, at some point the circuit board was changed to allow all CVs to be read and written. The manual was never updated. To access the other CVs, you first have to read back any of the basic registers. Then, after scrolling past R8, the display should change to C09. You can then alter any CV you want.

Now we move onto the complex CVs. These are for things like setting up lighting effects on the function outputs, and adjusting the decoder’s basic settings.

If you look at the decoder instructions, you will come across something like this:

To the beginner, this looks a bit daunting. How do we work out this lot?!

Well, each ‘bit’ can either be on or off. When it is off, it stands for nothing. When it is on, it stands for a number. What number? Each bit is worth twice the amount of the previous one. So when ‘on’ bit one is worth 1, bit 2=2, bit 3=4, bit 4=8, bit 5=16, bit 6=32 etc. So each decimal number corresponds to a unique combination of ‘on’s and ‘off’s.

Still following this? Don’t worry, I’ll show you an example. Take a look at the table for CV29. Suppose you wanted to set up the decoder with normal direction, 28/128 speed steps, operation on DC, standard speed curve, and with CV1 as the address. This means that bit 2 and 3 are on, while the others are off. This means the number we need to set is 2+4=6. This is the default setting for most decoders.

If you wanted to use a custom speed-curve (set up using other CVs) we need to switch on bit 5. This adds 16 to the number, making it 22.

You can apply this process backwards to work out the current settings. Suppose you had a reading of 5 on CV29. The only way to get this number is 1+4, so bit 1 and bit 3 are on.

This process seems a little complicated just reading it, but it’s a lot easier once you get the hang of it, and is far easier to do than it looks- have a go. The hard part is converting binary to decimal. You can actually use your computer’s calculator to do this if you can’t do it mentally.

One final tip: if you completely screw up the programming of your decoder, entering a certain value (depending on the decoder) in CV8 will reset the decoder to factory settings.
Last edited by pete12345 on Fri May 23, 2008 12:49 pm, edited 1 time in total.
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Re: DCC for beginners (Part 4 now up)

Postby sishades » Fri May 23, 2008 12:32 pm

33 in CV8

This varies according to the chip being used. TCS and Bachman use 2 and 8 in CV 8 to perform a rest.
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Re: DCC for beginners (Part 4 now up)

Postby pete12345 » Fri May 23, 2008 12:50 pm

Article edited: thanks for pointing that one out

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Re: NRM Article - DCC for beginners (Part 4 now up)

Postby tinman » Tue Sep 15, 2009 1:23 am

Very useful article thanks, especially as I'll soon be starting to lay & wire track !

Is there anything special that needs to be done with diamond crossings and double slips ? (both peco code 75 electrofrog in my case)

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Re: NRM Article - DCC for beginners (Part 4 now up)

Postby BROADTRAIN1979 » Wed Oct 28, 2009 4:52 pm

Hi ,
As my layout is 4ft 7" by 3ft and is 'n' gauge, (it is dcc) my feed wires are here and there, but for better loco command, is it good to have feeds, every section of track? My track is clean but my 37 does stall, here and there .Is that because ,i havent enough feeds? and also ,is 00 scale dcc different to 'n' scale dcc? as my dads, oo scale trains, run almost to zero ,over uneven track, where mine dont.I imagined all dcc scales were the same .
Youll never find a 501 like mine.

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Re: NRM Article - DCC for beginners (Part 4 now up)

Postby hiffano » Mon Jan 23, 2012 12:40 pm

hey there, any chance of


a - compiling this into one post/or downloadable PDF,


b - would you mind if i compiled this into one pdf, and happily share it with the rest of the forum.
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Re: NRM Article - DCC for beginners (Part 4 now up)

Postby jimp » Thu Apr 01, 2021 11:44 am

Why not just copy each each part that you want and paste in eg Word?
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Re: NRM Article - DCC for beginners (Part 4 now up)

Postby centenary » Fri Apr 09, 2021 8:42 pm

Charlie at Chadwick MR has just released a good vid on You Tube regarding cvs.

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