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Update to Runaway Zephyr Problem

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Update to Runaway Zephyr Problem
Posted by Anonymous on Tuesday, September 21, 2004 9:04 PM
Thanks to everyone for the replies. Digitrax and I had quite a telephone conversation this morning. In short, they want the DCS50 back to take a look at it.

This afternoon, I did reprogram CV29 to 34. According to the manual, this should have set analog mode conversion off, but a test with two different locomotives yielded the same results as before.

I'll be shipping the command station off in a couple of days. (It'll give me a chance to do some scenery work that I've been postponing anyhow.)

Thanks again & happy railroading.
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Posted by CP5170 on Wednesday, September 22, 2004 9:10 AM
Setting CV29 to 34, as I understand it, Normal direction of travel is set to normal; speed steps are set to 14; analog mode is "ON"; speed table is ON and 4 digit addressing is ON.

You want to set analog mode "Off" which would give CV29 a value of 30.

Ken
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Posted by cacole on Wednesday, September 22, 2004 10:39 AM
The following are the values for CV29. Add values together to get the final result that you need to program into CV29. A zero means to skip over this value, and a 1 means to use this value. What you're doing is setting bits on or off within one byte of CV29.

32: 0=short (2-digit) address; 1=long (4-digit) address.
16: 0=Use build-in speed table; 1=use custom speed table.
8: 0=Advance Acknowledgement Disabled; 1=Enabled.
4: 0=DCC Operation only; 1=Power Conversion On (DC or DCC operation).
2: 0=14 speed steps; 1=28/128 speed steps.
1: 0=Foward motor direction; 1=Reverse motor direction.

These values assume that you have a decoder and command station that support each option.
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Runaway complication..
Posted by jacon12 on Wednesday, September 22, 2004 8:47 PM
As I read the last fine post that goes into a lot of helpful detail, I can't help but think how complicated this is. Hopefully I'll be doing a first layout soon and want to use this same system, but reading this is giving me second thoughts.
I mean, you'd think this was NASA programming am orbiting satilite. It seems like the manufacturer could simplifiy this. Are all the other systems this complicated?
 HO Scale DCC Modeler of 1950, give or take 30 years.
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Posted by Anonymous on Wednesday, September 22, 2004 9:06 PM
The CVs discussed are Configuration Values (or Variables -- I forget which) that are part of every decoder, regardless of vendor, and allow you to tweak the decoder settings as little or as much as you like. There are a couple of required ones that every decoder has to have, and then a few to a lot of optional ones depending on the vendor, type of decoder, etc.

Getting a DDC decoder equiped loco to work can be as simple or as complex as you want to make it. Out of the box, the only change you absolutely should make to one is to set its address to whatever you want from the default of 03. If you don't have a lot of locos, you can use 2-digit addresses, or you can use 4 (usually the loco number) if you prefer. Once you do that, you can put it on the track and usually it'll run fine with the rest of the CVs at their default values.

It's when you want to start tweaking the loco's performance or fine-tune certain features that you have to get into modifying other CVs. It sounds complex, but it doesn't take long to figure out how to do it. And do it once, and it'll make sense and become second nature after a while. The decoder vendors usually provide pretty good basic documentation with the decoder, and folks like Digitrax have complete programming manuals that explain as much as you'd like to know.

It's almost a lot easier to do than to explain, and most of the DCC command station vendors make it pretty straightforward to do the programming.
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Posted by rexhea on Thursday, September 23, 2004 11:43 AM
[#ditto]

I agree 100%. Decoders are ready to run with the only exception being the address for your loco. True, some CV's lean to the complicated side, but you rarely have to mess with them. Most are as simple as selecting the CV you want and enter a value of 0-16 or 0-255 and enter. That's all.
Example: If its a sound decoder and you want to increase the volume of the bell, just select its CV, enter 0-16, hit enter. Don't get me wrong, some CV's are set up where they each control more than one function. These you have to have to get involved with 1's and 0's , but again its like following the bouncing ball.
Rex "Blue Creek & Warrior Railways" http://www.railimages.com/gallery/rexheacock
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Posted by bcammack on Thursday, September 23, 2004 12:11 PM
See if you can find a simple tutorial on the Internet (I suggest google to search) about digital math using hexidecimal and binary (base16 and base2) numbers instead of decimal (base10) numbers.

CV29 is clearly a "bitmapped" configuration variable, hence the number sequence given above. In binary representation, this is obvious as shown below. (x=bit position)

00x0 0000 = 32: 0=short (2-digit) address; 1=long (4-digit) address.
000x 0000 = 16: 0=Use build-in speed table; 1=use custom speed table.
0000 x000 = 8: 0=Advance Acknowledgement Disabled; 1=Enabled.
0000 0x00 = 4: 0=DCC Operation only; 1=Power Conversion On
0000 00x0 = 2: 0=14 speed steps; 1=28/128 speed steps.
0000 000x = 1: 0=Foward motor direction; 1=Reverse motor direction.

As you can see, each value sets or clears a single bit in binary representation. This is convenient and useful when programming the microcontroller used on that tiny decoder to operate the locomotive and options because every clock cycle and byte of memory on that tiny chip is precious. As a result, it is simply impossible to somehow hide this complexity with a more user-friendly face at the the decoder level.

My suggestion is to see if there are any good "helper" applications available for your computer where you can select which features you wi***o enable for a particular CV and it produces the correct numeric value you need to program into that CV. If there isn't one, I could probably do something provided that the configuration data is available freely somewhere.
Regards, Brett C. Cammack Holly Hill, FL
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Posted by robengland on Thursday, September 23, 2004 7:51 PM
get a LocoBuffer II device to connect an old PC to a Digitrax system, then download JMRI - free software that includes DecoderPro. Now you program your decoders via a nice GUI interface using a mouse. The difference is like from night to day!!
(Though I must say I think from memory DecoderPro misses the Analog ON/OFF function!)
Rob Proud owner of the a website sharing my model railroading experiences, ideas and resources.
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Posted by Anonymous on Thursday, September 23, 2004 11:07 PM
The latest version (1.4) of DecoderPro has the Analog ON/OFF function.
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Posted by Anonymous on Thursday, September 23, 2004 11:09 PM
QUOTE: Originally posted by CP5170

You want to set analog mode "Off" which would give CV29 a value of 30.


Is there any advantage to turning it off? I haven't been, even though my new layout is going to be 100% DCC, and it's doubtful the locos will ever run on a DC layout.
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Posted by jfugate on Thursday, May 26, 2005 1:57 PM
QUOTE: Originally posted by jsalemi

QUOTE: Originally posted by CP5170

You want to set analog mode "Off" which would give CV29 a value of 30.


Is there any advantage to turning it off? I haven't been, even though my new layout is going to be 100% DCC, and it's doubtful the locos will ever run on a DC layout.



Joe:

YES!

You want to turn analog conversion mode off, otherwise some decoders will occassionally misinterpet a DCC power fluctuation and either stop responding to any DCC commands, or take off at full speed.

On a DCC only layout, there is no need for this headache. Setting this function off increases the reliability of all decoders to sensing DCC commands, in my experience.

And moving to DecoderPro (free!) greatly simplifies decoder programming.

P.S. (shameless plug) In my upcoming DCC video, I give a complete step-by-step demonstration of installing and using DecoderPro. The video should be out by late June. For more info, here's a link to the distributor's web site: http://mymemoirs.net/model-trains-set1-vol3b.php

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

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