FORUM CLINIC: 12 years using DCC - SIGNIFICANT NEW INFO!

[selector]

I've seen it, Joe. Pretty neat stuff. If I build another, more ambitious layout with more locos, I will get into this latest series of posts. Right now, my SEB and two DCC locos are all I can handle!

[ereimer]

so many posts that threads tend to get lost . we really need to get sticky threads around here !

[Bob Hayes]

If you click on "Watch this topic", the forum will notify you when there is a reply, and you can just click on the address that's included in the email. Of course I haven't been following my own advise, so I end up looking through the forum until I find this thread. Sometimes that is good, sometimes not.
Bob Hayes

[jeffshultz]

Joe,

Just went through and got caught up with this thread and the scenery one. I've got the Design for Ops one bookmarked.

They look like they'll make a great working aid along with the DVDs.

And I finally understand how you are wiring in the 1156s - the NMRA Conference DVD jumped straight to the last slide and my eyes crossed tracking all those wires!

With any luck I'll get my father-in-law to look at this thread, he just bought a Digitrax Zephyr w/radio rcv'r and a UT-4R.

[chateauricher]

QUOTE: Originally posted by ereimer

so many posts that threads tend to get lost . we really need to get sticky threads around here !

I agree wholeheartedly.

To the powers that be : please sticky this and the other forum clinics.

[Bob Hayes]

I find this very interesting; Joe gets upset if there are no responses to his clinic chapters in the first 1 or 2 days, but he hasn't posted any up dates to this forum clinic in the last 7 days and I note he is not on vacation! To paraphrase other posters "What's up with" Joe?

Bob Hayes

[jfugate]

My nose is in video land at the moment trying to get video volume 3 put to bed. It was originally due out in May, but the comments from the postings on this topic have helped me see where certain topics needed more work.

So I'm adding another 20 minutes to an already 80 minute video to make sure it's as clear and understandable as possible. Technical material can be really bad if it's confusing, and I want this video to be the best yet, and full of *very useful* material.

So that's what I've been up to in the last few weeks, and I'm pushing hard to get done so we can ship it in July.[:D]

I plan to post the next installment on here within the next day or two ... I'm alive and well -- just very, very busy!

[jfugate]

TOPIC NEXT POST: Super-simple decoder programming with DecoderPro

Okay, you've got your computer connected to your command station, now how do you use DecoderPro to do it's thing?


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Let's program this Kato SD45, SP 7444, on the programming track. I have a Digitrax DH142 decoder installed, and I need to set up the decoder for this loco. I place the loco on the programming track, and fire up DecoderPro on my laptop, which is connected to my EasyDCC system with a special serial cable as we discussed earlier.

Click the “Use Programming Track” button.


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In the service mode programming window, we select the decoder type from the list, which is a Digitrax DH142 ...


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... and click “open programmer”.


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The progamming window comes up and we fill out the first panel with some basic info we want to keep about our loco like it's ID - SP7444, road name - SP, road number 7444, manufacturer – Kato, and model – an SD45R.


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MORE TABS, MORE THINGS WE CAN PROGRAM
Let's see what other tabs we have ... we have the basic tab, which lists general address configuration settings, then we have the motor tab, which lets you set acceleration, deceleration, and motor voltages.


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The speed control tab allows you to program detailed speed curves, the function map tab lets you remap function keys (depending on what the decoder allows), the lights tab lets you set how you want any headlight effects to work, the consist tab lets you make the loco part of a consist, the advanced tab lists any extra decoder features ... the CVs tab lists all the CVs in a spreadsheet like format, and the vendor specific tab – Digitrax in this case – lists any extra special settings that apply only to Digitrax decoders.


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Focusing on the basic tab for a moment, I set the primary address to 44 since I use the last two digits on the cab when I use the short address. I set the long address to 7444, which is the full address of the loco. I stay with the normal direction default of forward, and set the speed steps to 28/128. I make sure analog conversion mode is always off on all my decoders, since I find decoder performance to be much more reliable with this setting.


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Finally I put my private ID in the two fields at the right.

Looking at the buttons on the bottom for a moment we see you can read changes on the sheet, write changes on the sheet, read the full sheet, or write the full sheet.


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HOW DECODERPRO MARKS FIELDS FOR YOU
DecoderPro marks all fields at program startup to yellow. If you change the value of a field, it sets the field to orange. If you click write changes on sheet, it will write only the orange fields to the decoder. As it writes the fields, it sets them to red. Once the fields have been written to the decoder, they change to white.


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I don't recommend you use the read buttons very often unless you are willing to be patient because the command station has to do the 20 questions approach, asking “are you a 1, are you a 2, and so on” which can be quite slow. Never do “read full sheet” unless you are going to lunch because it can literally take that long to read back all the CVs in a decoder.

If I want to know what the values are in a decoder, I write them to the decoder using DecoderPro, then save them to the PC. Since I use decoderPro exclusively now to set CVs, I can just bring up the file later on the PC if I want to know what the CVs are set to. If the loco is acting funny, I'll just put it on the programming track and reload all the CVs with DecoderPro and that usually fixes the problem.

Moving on the motor tab, I typically set the kick start value to 10, the acceleration rate to 4 and the deceleration rate to 4. I find just a slight bit of delay smooths out the loco response but isn't so much that it irritates my operators.


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The last three compensation settings are for back emf on Digitrax decoders. I stay with the default of 128 for static compensation, but set the dynamic compensation to 5 and the droop to 8. This gives a gentle back emf compensation to smooth loco operation, but that still requires you to work the throttle some on curves and hills. Too much compensation makes the loco run the same speed everywhere – up hills, down hills, through curves – which is a great trick, but not very realistic.

We write these settings to the decoder, and then move to the speed control tab.

I prefer to use speed curves in all my locos, as opposed to voltage settings. For the moment, I set the first speed step to 18 and click constant ratio curve. I leave the forward and reverse trim at the default of 128, and we write the changes on the sheet to the decoder.


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Click “Save” under the file menu to save your decoder settings to disk.


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TOPIC NEXT POST: Cool ways to use DecoderPro for programming on the main

[simon1966]

Thanks Joe, I appreciate your hints on your default settings. I have used Decoder Pro for a few months now and could not imagine programming without it.

[oleirish]

What is the best wireless systeam to get and what is the cost??

[jfugate]

*Best* is a loaded term. Cheapest? Most user friendly? Best radio reception range? Most features?

[jxtrrx]

Joe, you are a tremendous asset to our forum. I add my thanks for your clinics… very helpful stuff for me. I can’t afford the Serial to USB interface and Digitrax interface required for the computer programming yet, but sounds like good stuff for the wish list.

[jfugate]

jxtrrx:

Thanks ... I love to teach, and this forum, as well as the how-to videos I'm producing give me a chance to take the hobby I love and join it with teaching!

The Siskiyou Line video series allows me to put useful how-tos onto video, and after that series is done, who knows? I'd like to see an entire library of how-to videos built up and made accessible over the internet. Nothing like watching how it's done to finally "get it" ! [:D]

[jfugate]

oleirish:

No response as to what you meant by "best" wireless system, so I will define best as "best radio reception" in terms of reliability, and add the requirement that the throttle must be truly wireless with no need to ever plug in (rules out Digitrax). And further, the throttle must use a rotary knob for speed control, not a keypad (rules out Lenz).

This leaves the other two biggies, NCE and EasyDCC. I have EasyDCC and have used NCE wireless on a few layouts as a guest operator. I've also downloaded and read the manuals for NCE.

My experience using NCE wireless was less than stellar. Reception was not always reliable and subject to odd behavior. One case in particular had the owner so fit to be tied that he said if NCE didn't get this problem solved, he was seriously considering changing systems. I have heard NCE doubled the length of their receiver antenna and strengthened the signal a bit in an attempt to improve things, but I have not heard if this has solved these teething pains.

EasyDCC wireless, in my experience, was a bit finicky when I first got my system in 2000, with reception sometimes being poor at one extreme end of my layout behind a peninsula and a house wall. I did find that even in this location if I dropped the throttle down below my waist and pointed it at the ground, the signal was received -- so I had a workaround and I just taught my operators to do that if they had a reception problem.

In 2002, they released a firmware upgrade for the EasyDCC system and receiver. Immediately the reception problem went away and has been rock solid ever since. So in my experience, the most reliable wireless reception is EasyDCC. And the EasyDCC wireless throttles are about $20 cheaper than the NCE wireless throttles.

All purely my personal preference and opinion, of course. Each person must define *best* for themselves, and you can see here how I have defined it for myself.

[simon1966]

JMRI just released a new version (1.6) which offers a number of new decoder definitions and other enhancements. I have downloaded it but not had a chance to play with it yet. I don't think that this release has the full QSI support implemented yet.

[jfugate]

Cool! Thanks, Simon, for the heads up!

This release completely rewrites the EasyDCC interface, which is something that interests me since that's what I use. [:D]

[Rob Davies]

Joe,

Just a quick note of thanks regarding your section on DecoderPro and the example Digitrax setup. I use a RoCo LokMaus 2 setup, which allows you to program a decoder via a Lenz LI101F serial interface (but not able to read a decoder - for half the price of an Atlas Commander setup, I'm VERY pleased with it!). I recently bought a DH631ip for installation in a Kato SD40-2 - the default settings of the decoder were a LONG way from perfect for the SD40. Luckily, I remembered your clinic on decoder setup and, thanks to you I have a VERY sweet running Kato/Digitrax loco running.

Cheers Joe!

-Rob in the UK

[jfugate]

Rob:

Excellent! Makes me think it might be useful just to have an exchange where people post their typical decoder CV settings that work well for various loco and decoder brand combinations ...

[Anonymous]

Joe, your last three posts made me realize that I want/need something I didn't even know existed. When you first started on DCC and computer connections, I thought that I would be skipping the next few installments (small, simple layout - don't need computer hook-up), but boy would I like to be able to program decoders like you show using DecoderPro. It's on my wishlist.

Now for a stupid question:

I had decoders installed at the LHS. Not sure I know or can easily figure out what decoder is in what loco. Will DecoderPro recognize what decoder is installed or is that something I will have to figure out before I can use DecoderPro to program the already-installed decoders?

Thanks once again for all the knowledge you share with us (particularly guys like me who know so little).

John

[jfugate]

John:

Great question! That's one of the nice things about the group that has banded together to produce DecoderPro. They've also compiled a list of CV7 and CV8 values for all decoders, making it possible for you to determine what's inside the loco without taking off the shell. [:D]

Here's a sample of this list:
[code]
Manufacturer Model CV7 value CV8 value
============ ======== ========= ==========
Atlas 340 45 99
Atlas 341 45 127
Atlas LE063XF 45 127
CVP Products AD4 62 135
CVP Products AD4 61 135
Digitrax DN144 105 129
Digitrax DH121 34 129
Digitrax DH142 250 129
Digitrax DH150A 107 129
Digitrax DH150K 107 129
Digitrax DH163IP 49 129
Digitrax DN140 107 129
[/code]

If you want the whole list, you'll need to go to the DecoderPro Yahoo List ( http://groups.yahoo.com/group/jmriusers/ ) and subscribe. Then in the database section, you will find a file called: Decoder Versions. You can download it to a spreadsheet if you want -- that's what I've done.

I've moved the CV8 column to the left of the CV7 column, then resorted the list by CV8, then CV7, making it very easy to look up the values and from there to determine the decoder that's installed.

NOTE: CV8 is the manufacturer number, and CV7 is the decoder version number. Using those two values and the list from the DecoderPro Yahoo List site, you can find out what's inside the loco just by reading a couple CVs.

[Anonymous]

Thanks, Joe. You're making this too easy. Now I'll have to explain to my wife the new gear to connect the MRR to the new notebook. Actually she is very supportive and probably will even let me use her notebook. I use desktops, which are not conveniently located to the train room.

J

[rrinker]

Of course you're aware that by using DecoderPro and the IDENT function in the Comprehensive Programmer, it will tell you what the decoder is, without having to manually read CV7 and CV8.

A list of various decoder settings for differetn decoder/loco combinations is a GREAT idea, I will add a section to my web site for the ones I've done. Like the recent conversation between myself and another user ont he QSI group (about a Digitrax decoder, go figure) - I experimetned and worked out a setting for the 3 CV's thaton Digitrax Series 3 decoders controls the torque compensation to make a Proto2000 SD45 run nice and smooth. The other person tried those settings in an Atlas loco with no joy, well,t he Atlas motor and drive IS superior to the Proto2000's so that is to be expected. But if anyone has a DH163L0 in an SD45, I can provide settings that make it run much nicer than the defaults. Slower, too, the stock top speed is somewhere around 200 smph. As soon as I adjust my GP-7's, I'll have a list for those, as well.

--Randy

[chateauricher]

Joe,

In another thread, someone said that the traditional DC systems use DC (direct current) electricity of variable voltage to control the speed and direction of a locomotive. While I agree with and understand that; they also said that DCC uses AC (alternating current) electricity.

I don't think they are correct, but I haven't found any information about it to back up my argument. Except that : if DCC uses AC current, then how is it possible to run a DC current non-decoder-equiped locomotive on a DCC system? Are DC motors built to work with AC electricity? If all you need to do is install a decoder in a locomotive to make it DCC-compatible, then why don't you have to change the motor so that it is AC-compatible?

So, my question to you, Joe, if you would be so kind to answer ...
Does DCC use AC or DC electrical current?

[jfugate]

Timothy:

Strictly speaking, DCC puts square wave AC to the track. So to measure things like track voltage and so on directly, you need to use AC equipment -- however AC measuring equipment won't work exactly right, because most AC equipment is not designed to measure square wave AC.

Okay, now the clever part is how DCC does the square wave AC ... they put a square wave on the rails that is + voltage for a fraction of a second, then - voltage for exactly the same duration as a the + voltage. What this does to a straight DC loco is the + and - voltage cancel each other out, so the motor just buzzes softly and a straight DC loco does not move.

The sneaky part is you can make just the + or - part of a wave longer, to create a voltage differential across the rails -- and make a straight DC loco run on AC! That's how the '00' address to run a DC loco works.

The square waves are actually encoded digital signals to the decoder. Each normal duration square wave is a pulse that the decoder sees as a 1, and each extra large single pulse the decoder sees as a zero.

DCC sends its commands down the track as a series of these zeros and ones, like this: 10010110 11101111 00110111 00001000 and so on. Every place you see a 1, you get a brief + and a matching - voltage square wave. Every place you see a zero, you get an extra long +/- voltage square wave.

With AC on the rails, it's a simple matter to have some diodes in the decoder to filter the AC voltage to turn it into pulsed DC for the motor. The decoder listens for commands sent down the rails addressed to it, and then controls the filtered DC voltage it allows the motor to receive.

The specific details of what's going on with DCC are basically correct above, but I've glossed over lots of pesky details to convey things in simple terms.

The short answer is DCC is AC, and you can turn AC on the rails into DC to the loco motor with some diodes in the decoder -- or create a plus or minus voltage bias across the rails by making asymetrical AC square waves, and get a non-decoder equipped DC loco to run!

[chateauricher]

Joe,

Thanks for explaining all that. It makes much more sense now.

So, just who is the insane genious who thought up all this DCC/square-AC-pulses/asymetrical-AC-waves business ??? [;)][:P]

[oleirish]

Joe;
Your work is great on DCC,but I'am thinking about going back to analog because of the cost and time spent under the train board wireing,All most everything written on DCC says you need all these bus lines under the board,and even been stated that you need feed lines everywhere your track is joined,then reverse loop things,then worrying about your switch frogs if there not right,rewireing them and so on,and so on?on top of all of that you need to solder every joint so your DCC works right,if your track is layed right ,you do not need to solder every joint,good rail joiners are a must thats all[soapbox]
I tryed the DCC and have no real problem with it but it looks like the wiring is just a much!I'am getting redday to start my new layout and hope my last one for a while,It will be in two 4'X6' sections so it, can be moved on down the line sometime .total 4'X12' I opreate my rail road by my self and sometimes the grandkids help.I still have to lay on m back on the floor to do the wireing.and analog is cheaper.I have two DCC unites and a couple of engines W/decoders.But to convert all my engines to DCC is expensive.Does any one make a wireless controlers for analog?
OLE'IRISH
JIM

[jfugate]

olerish:

If the budget is tight and cost is the most important, then I can't argue with you that DC is cheaper. Although I would take issue that the wiring is any simpler with straight DC if you still want to run multiple trains. If having totally independent control of each train is most important and other things are secondary, wireless DCC is hard to beat.

Most of the DCC wiring practices simply add robustness to the wiring to make it reliable, and make debugging problems easier. And the extra work is *not* that much harder. I and one of my modeling friends completely rewired the power feed side of the Siskiyou Line to take advantage of the 1156 bulb short management in 2002 and it took us three 8 hour days to do it, at a cost of about $100 in new parts and materials.

The result is a very short-resistant and reliable Siskiyou Line layout from the wiring side.

Watch the ads in MR for analog wireless throttles ... but you'll pay nearly as much as you would for a DCC system, and you won't have the operational flexibility DCC gives you.

[jfugate]

QUOTE: Originally posted by chateauricher

Joe,

Thanks for explaining all that. It makes much more sense now.

So, just who is the insane genious who thought up all this DCC/square-AC-pulses/asymetrical-AC-waves business ??? [;)][:P]

Lenz came up with the original DCC spec they gave to the NMRA for free, so I would suspect it was their *genius* that came up with this.

[#offtopic]P.S. Permit me an off-topic comment: look at what Lenz did versus how MTH has approached DCC. Lenz is one of the big four in DCC today so their contribution to the world hasn't hurt them one bit. MTH on the other hand is considered by many to be the "robber baron" of the manufacturers in the hobby with their lawsuit orientation.

What a contrast!

[Anonymous]

Jim,

I can't argue with cost, but I would have to say that good DC wiring practices are exactly the same as good DCC wiring practices (maybe with the exception of the lightbulb breaker). Many of my train buddies (who have been in the hobby much longer than I have) couldn't see what all the fuss was about "DCC friendly" switches because they had been using the same practices in DC for many years!!!

As for wiring multicab control in DC, DCC is by comparison far simpler.

[n2mopac]

I'm just curious . . . I know it's been a holiday and all, but I'm wondering if this clinic is played or if there is still more to come?

Ron