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It has been noted in another thread that CV29 is made up of a number of bits in binary either 0 or 1 all of which are converted from binary to duodecimal which is then presented in the form of a CV number when read back. I was wondering if there was any table for this anywhere as there are 6 bits of data each of which represents a decoder setting.

As set out in the Bachmann table of CV values for CV29:-

Bit 0 = direction of travel (Normal or reversed)
Bit 1 = Speed steps (14 or 28/128)
Bit 2 = Loco operates on DC (yes or no)
Bit 3 = Not used?
Bit 4 = Speed curve selection (CV's 2,5,6 or CV's 67-96)
Bit 5 = Short or long address (2 or 4 digit)

Now whilst the Elite can read and write CV's it cannot read or write bit data. Are there consoles available that can or does this matter as these bits can be altered by entering an appropriate CV which is then converted to binary. Given that there is an appropriate table available of course!

Happy modelling
Gary
 

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This link to an article on Wikipedia "Hexadecimal" will start you off. The table near the top the article sets out the codes for 4 bits of data which covers 0 to 15. I am sure someone will else be along shortly to point you at a more complete table.

If you (or your kids) happen to have a scientific calculator, there's a chance that it has a Hex mode. If it does, you could use this in conjunction with the Wiki article to do the conversions.

When I am working with bits as you are for CVs, I actually find it easier to work in Hex. I write out the settings I want and then convert the groups of 4 bits to hex. It seems more natural to me than adding 128 to a value just to set bit 7.

David
 

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Further research and it is now clear why CV's very often have a setting range 0-63 as each CV is made up of 6 binary bits.

111111 in binary = 63
000000 in binary = 0

Suddenly this DCC lark is becoming clear!


Happy modelling
Gary
 

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Were working with Binary here

Please forgive me if this is wrong, but it is Friday night and I'm in France and we are already on aperitifs...

Bit 0 = direction of travel (Normal or reversed)
Bit 1 = Speed steps (14 or 28/128)
Bit 2 = Loco operates on DC (yes or no)
Bit 3 = Not used?
Bit 4 = Speed curve selection (CV's 2,5,6 or CV's 67-96)
Bit 5 = Short or long address (2 or 4 digit)

Binary is made up on 1's and 0's
The Decimal value is the number to add or subtract to enable or disable the setting.

Bit 0 (Speed steps) - on the right
0 = locomotive's direction is normal
1 = locomotive's direction is reversed
Binary value 00000001
Decimal value 1

Bit 1 (direction of travel)
0 = Operation with 14 or 27 speed step systems..
1 = Operation with 28, 55 or 128 speed steps.
Binary value 00000010
Decimal value 2

Bit 2 (Loco operates on DC)
0 = locomotive operates in digital mode only
1 = locomotive can operate on either conventional DC
Binary value 00000100
Decimal value 4

Bit 3 (Enable RailCom - in enabled decoders)
0 = RailCom transmission disabled
1 = RailCom transmission enabled
Binary value 00001000
Decimal value 8

Bit 4 (Speed curve selection)
0 = factory pre-set speed curve is used
1 = user defined speed curve is used. Enter the appropriate values into CV 67 to 94 before setting this bit.
Binary value 00010000
Decimal value 16

Bit 5 (Short or long address)
0= Normal addressing
1= Four digit extended addressing
Binary value 00100000
Decimal value 32
 

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Discussion Starter · #5 ·
Hey thats it!

All you do is add up the numbers for the appropriate settings that you want and write that in as the CV value for CV29. 0 = 0 and 1 = the appropriate number 1,2,4,8,16 or 32 and add them up.

Nice and simple. Cheers Doug!


Happy modelling
Gary
 

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And people say DCC is easy !!!
From the above, it seems one needs to be a mathamatician to re-programme a loco for it to do what you want it to do.

Me, on my DC layout, if I want the loco to go right irrespective of which way it is facing, my direction switch is set to the right. Simple programming.

Ron
 

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Come on Sol it's not that difficult and you only have to go through that exercise once, to understand it. More importantly you can then fully enjoy the fruits of your labour, with simplified wiring, superb slow running, individual characteristics of loco's, automation if you want it, seamless reverse loops, sound, all sorts of goodies you can turn off an on. Comparing DC to DCC is like comparing clock work to DC. I will never return to DC.
 

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It took me quite while to "get my head round" CV29


Once you get past basic settings (or programming) it is probably the most important one to get right. If strange things are happening I usually reset this CV only to defaults & try again before a full factory reset.
 

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MMAD, I know what you are getting at. It is just that some people have problems programming a VCR.

I operate on a USA style DCC layout & follow the loco & I enjoy that having locos tuned for running is ideal especially if double heading.

On my home DC layout, the method we ( 5 of us in the group) use in operating is to stay at the station & drive the train from the previous station, shunt as required & let the next station take it out. We do not follow the train.
Sounds don't turn our group on;reverse loops no problems with that for me - I have a simple circuit using a full-wave bridge rectifier & no special reversing switch ;wiring I enjoy; locos run slow enuf for shunting using good DC control circuits ( & our group all use the same type of control circuit over 5 layouts); 4 stations ( 2 stations can have 2 operators working) with 3 goods trains out at on the tracks any one time & one passenger train at any one time;we do not have to know which way the loco is facing to drive it from hidden sidings or distant stations.
I have shown this layout & its system to many DCC people here & they all say, the way we operate, the cost of converting to DCC would not improve our operations. In fact there are some aspects of DC control that cannot be duplicated in DCC for the same method & cost.
I have done cost of converting to DCC for upto 5 operating handpieces & at least 10 locos to be decoded & it comes to $1600+ - about £640 - a bit much I thought.

Not withstanding that, for any new modeller coming into the hobby, yes DCC is the way.

Ron
 

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Discussion Starter · #11 ·
QUOTE Once you get past basic settings (or programming) it is probably the most important one to get right. If strange things are happening I usually reset this CV only to defaults & try again before a full factory reset.

Looking at various CV guides I'd go along with that hence a focus on it in this thread. An understanding of the mechanics of CV29 should set any modeller up in good stead for DCC and really it is the way forward.

Whilst budget DCC consoles and decoders are fine if all you want is directional and speed control of locomotives on the same track with limited function control, I'm as now convinced as anybody else that a console that can read and write CV's is the way to go! Now who would have thought that I would have had that opinion just a few days ago!


Happy modelling
Gary
 

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Gary, if you think you are having fun now, just wait until you get to the automatic stopping you get with the Lenz "ABC" feature which is now available from ESU and Zimo as well.

David
 

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>Should we let him into the secret sanctum?
There's a secret sanctum?

David
 

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OK Gary can join - but I think we should have a poll Doug to see if he qualifies !

I'm delighted to read Gary's comments. Now you join us to preach the importance of features, amps, and handhelds. Ah you still have to experience the joy of a Radio throttle, no trailing wires, almost complete freedom. Gary I hope your budget will reach to a decent DCC set-up. Hornby users are considered to be on probation until they acquire something more salubrious.
 
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