I have a Bachmann high boiler 4-6-0 w/DCC & sound that starts at a fairly high speed and I’d like to get better starts & slow speed operation. I assume it is factory set for 14 speed steps and I’ve been trying to reprogram CV 29 to a value of “34” (based on reading here on the Forum) with my MRC Prodigy Advance 2 throttle, but after doing so the loco won’t respond to any inputs (default sounds still play). I have to reset the decoder to the factory defaults (CV 8 = 8) to get it to respond again. What am I likrly doing wrong?
I believe CV29’s default value of 6 creates a situation with no speed tables, analog mode OK, 28/128 speed steps, normal direction, and short address only.
I think changing it to 34 only changes it to allow long addresses, and to turn off analog mode (so it won’t work on DC). Rest is the same.
I’d suggest checking to make sure CV2 is at zero (start speed) and set the momentum (CV3-4) to say 15 or 20 and see how it starts and stops then.
I believe the loco has the factory Soundtraxx sound decoder and I’m trying to get it to start smoother (it takes off fairly abruptly similar to the Bachmann 2-8-0 reviewed in the September 2018 edition of MR; unfortunately I misremembered the review thinking it was set to 14 speed steps rather than the 28 stated in the article). I’m fairly new to DCC (obviously) and getting this 4-6-0 to operate smoothly has baffled me thus far.
I got 34 by assuming that my MRC DCC system uses long addresses, so using this calculator http://www.2mm.org.uk/articles/cv29%20calculator.htm with the box for long addresses and DCC-only operation checked, I got a value of 34 (which didn’t work).
I believe you but if the calculator says 36, is there that much…elasticity, slop, tolerance in setting CV 29?
To the OP, much of what has been posted here in the past about 14 speed steps is that it gives you less control and more abrupt changes. That’s why people are suggesting changing starting voltage and the like. Keep a record of what you try, because if you will forget that you tried something before that didn’t work.
We haven’t explained why he lost the engine by setting it to 34, unless the loco was on short address.
It was established in another post the locomotive is equipped with SoundTraxx OEM Bachmann feature set using Tsunami technology. Thus the decoder installed is not “Sound Value” or “Ecomomi”.
The loco is set to the default address 0003 (# shown on throttle display after I input “3” in loco selection), so I assume the MRC system automatically uses long addressing. Is that a bad assumption?
Locos come from the factory with an address of 3. A reset returns it to 3, if it has been changed. I don’t know MRC but DCC systems allow you to change the address to another short address or a long address.
How to do that should be in your manual and if you don’t have one, you should download one.
As I read the quote of yours above, yes, it’s an erroneous assumption. You must select, or know already if, the address is (to be) a ‘long’ one. Then, if it’s not the cab number decaled on the locomotive, you must record it someplace for when you want to go use it again after months. This is for those of us who have several locos we use in a long rotation.
According to Randy in a post about four months ago or so, the ESU decoders have a different cut-off point for long addresses, but pretty much all the rest use 127 as the point from which you must enable action to a long address on your system. But the point is, the system should ask. It should prompt as it does in the Digitrax systems with a ‘y’ or a ‘n’ when it flashes 'enable long address?"
I might be wrong because I only have experience with reading here over the years and with my own Super Empire Builder, an old Digitrax system using the early DT400 encoder twin throttles, but our screens do ask if we enter a long address.
One other thing Randy likes to drum into us is that you must complete the addressing by actually shutting off power to the rails momentarily. Digitrax, again that horrible system, does this automatically when you press the final enter to complete the address change. You must manually press to restore track power, and then your newly addressed loco should NOT respond on ADD ‘03’, but on whatever you pressed and entered.
My MRC system uses long addresses when I plug in 4 digit engine numbers. However, the 4-6-0 in question is undecorated, so I have left it as “3” per the default. My system does not ask if I want to use long addresses, so I assumed it does so automatically; that may not be the case. If so, then per the CV 29 calculator I listed above, the value should be “2” using a short loco address. I’ll try that out. Also, the MRC system manual doesn’t say anything about cycling power after programming when using a program track (which is what I have been doing) or on the main,
First they caution you not to monkey with CV29, then the give examples.
CV 29 for long address and the default setting is 34.
For long address and 14 steps it is 32.
That’s different than both Baron’s calculation and the Digitrax calculator. So there must be some proprietary leeway in the calculation of CV 29
So if you were originally running the loco as an address of 3 and you changed CV 29 to 34, you told it to use a long address without actually giving it a long address and it did not respond.
You are correct about the CV value of 34 - it didn’t match the short loco address of 3. I just set CV 29 to 2, CV 2 to 0 & CVs 3 & 4 to15 as recommended above and the loco still operates, but it doesn’t seem to perform any differently than the factory defaults. Perhaps the Bachmann just doesn’t allow nice, slow operation…
Given that we just discovered that multiple calculators give multiple results for CV 29, I don’t know that my loksound can speak for your situation but the minimum CV for CV 2 is 1 not 0. The maximum for the acceleration CV 3 is 255 with a default of 16 and the default for the midrange CV 6 is 64 which is also the max.
I’d say go up on CV 3 to extend the time to acceleration. Report back please, we are all learning here.
There is not. CV29 is a NMRA standard, there ar enot multiple calculated values. Someone fat fingered a value. I just tried the linked Digitrax oonline calculator and if you select 28/128, no analog, long address the value shown is - 34! 36 is long address, analog on, 14 speed steps.
34 is long address, 28/128 steps, no analog. Always. Anything that says different is incorrect. I tried 2 different online calculators, both give the same result. So does the Digitrax toolbox app.
2 is short address, 28/128 steps, no analog.
38 is long address, 28/128 SS, analog on.
6 is short address, 28/128. analog on.
About the only “it can vary” CV29 option is for Railcomm, which if turned on adds 8 to the above values. Only decooders that actually have Railcomm will support that bit being set.
Some decoders take a 0 in CV2, 3, and 4, others like TCS and ESU the minimum value is 1, but typically if you put it to 0 and then read back it will show a 1.