Strange results with Massoth decoder reading CV 29

[Airbuspilot]

We have a Loco which makes (Loud) engine start sounds each time main track power is turned on. It was suggested this could be as a result of the DC capability still active and I was recommended to switch it OFF.

I had no idea which decoder was fitted in this Loco so read CV 8 which came back with 123, I believe this is Massoth?

Reading CV 29 I had 0 as a result, I tried again and it read 2. Trying several times the CV read back alternated between 0 and 2. I tried to write 34 into CV 29 which was acknowledged, read back was again 0 / 2 / 0 / 2 ....

Presumably this is not correct behaviour for a decoder?

Am I in new decoder territory?

The Loco runs normally other than the engine noise on power up.

Robin

 

[phils2um]

If it has a separate sound card that could be interfering. I had a similar problem with my LGB 27402 Blue Crocodile. The LGB MTZ decoder and sound card in this loco are manufactured by Massoth. The decoder CVs could be read (and written) fine after unplugging the sound card SUSI from the decoder.

 

[Greg Elmassian]

Also, some keep alive boards will mess you up.

Greg

 

[Airbuspilot]

If it has a separate sound card that could be interfering. I had a similar problem with my LGB 27402 Blue Crocodile. The LGB MTZ decoder and sound card in this loco are manufactured by Massoth. The decoder CVs could be read (and written) fine after unplugging the sound card SUSI from the decoder.

Thanks Phil and Greg. I don't know if there is a separate sound card inside, I will take a look. As its so easy to damage very expensive Locos by taking them apart I'm a little surprised access to decoders isn't made slightly easer, not that access is needed every day but seems like access is needed often enough. Robin

 

[Ralphmp]

Which type of loco is it?

 

[Dan]

Some early decoders (55020, 55021) wound not do 128 speed steps and a 2 in CV29 is 28 speed steps. Be sure you set your handheld to 28 speed steps or results will be flaky!!

 

[LGB333]

What is the LGB # of the locomotive?

 

[Airbuspilot]

Hi Thomas. Not sure of the Loco number, I will go over to my friends house on Monday and check.
Robin

 

[Airbuspilot]

Some early decoders (55020, 55021) wound not do 128 speed steps and a 2 in CV29 is 28 speed steps. Be sure you set your handheld to 28 speed steps or results will be flaky!!

Hi Dan.

I am still in the process of getting my head around CV's. If I understand correctly Bit 1 in CV 29 is either ON or OFF i.e. 0 = 14 speed steps or 2 = 28 + 128 steps. By setting 2 I am allowing both only the handset to change for an old decoder working with 28 steps?

I have set most Locos to 2 assuming 128 steps, just to check I haven't made an error along the way.

Robin

 

[Greg Elmassian]

All "bits" are either 0 (off) or 1 (on) when looking at a CV value by bits.

by setting bit 1 to on the decoder will only work in 28/128 speed step mode.

(don't say 2, unless it is the "total" value of ALL the bits in the CV, so it's best to either give the decimal value for all bits in the CV (CV29 = 2), or to just specify the bit in question (bit 1 of CV29 is on/one)

Just a suggestion to avoid confusion.

Greg

 

[Airbuspilot]

All "bits" are either 0 (off) or 1 (on) when looking at a CV value by bits.

by setting bit 1 to on the decoder will only work in 28/128 speed step mode.

(don't say 2, unless it is the "total" value of ALL the bits in the CV, so it's best to either give the decimal value for all bits in the CV (CV29 = 2), or to just specify the bit in question (bit 1 of CV29 is on/one)

Just a suggestion to avoid confusion.

Greg

Thanks Greg.

I have just replaced the decoders into my own N scale Locos (with ZIMO) and set CV 29 = 2 in all of them as there are no long addresses and I am only interested in the 128 speed steps at this time. Dan's message talked about 28 steps and for a moment I thought I had made an error.

We do have some old Locos with the G scale layout which almost certainly need CV 29 bit 2 to OFF.

Robin

 

[Diesel2000]

There are lots of tables out there that show all the CV29 values (1-55) and what options those values control so you dont need to worry about bits at all.

 

[Greg Elmassian]

In my experience, people using tables made mistakes more often, since it is easy to get the wrong row.

Of course, you can tell that I recommend calculating the decimal value yourself, but my second recommendation is a CV29 calculator, on line, then there is only one answer in front of you.

(of course you know that table is incomplete, since it does not show all combinations, and the formatting of the title of the first column is foo so people don't know which column is which, and also who uses HEX any more?

sounds like I came down hard on your post, but honestly that is a crappy table, and we are trying to help, not make it worse.

greg

 

[LGB333]

Thanks Greg.

I have just replaced the decoders into my own N scale Locos (with ZIMO) and set CV 29 = 2 in all of them as there are no long addresses and I am only interested in the 128 speed steps at this time. Dan's message talked about 28 steps and for a moment I thought I had made an error.

We do have some old Locos with the G scale layout which almost certainly need CV 29 bit 2 to OFF.

Robin

Robin - FYI, for most of the decoders I install into customers' LGB locomotives, I set CV29=6 which provides for 28 Speed Steps and Digital and Analog operation. But some of the older LGB locomotives with the factory onboard DCC decoders installed, you need to consult the locomotive's User Guide.......some of these type older decoders had some special settings. That's why I asked for the LGB # of the locomotive you're concerned with on the decoder settings.

 

[Andrew_au]

Just to check - have you tried reading back other CVs? On one of my locos I get gibberish on read back on most CVs - this was both with the factory decoder (LGB 55021), a Massoth eMotion L I swapped in from another loco, and an after-market Zimo decoder I installed in a conversion harness. In order to program normally I need to move the decoder into another harness (another compatible loco or a test board), program it there, and move it back.

 

[Airbuspilot]

Robin - FYI, for most of the decoders I install into customers' LGB locomotives, I set CV29=6 which provides for 28 Speed Steps and Digital and Analog operation. But some of the older LGB locomotives with the factory onboard DCC decoders installed, you need to consult the locomotive's User Guide.......some of these type older decoders had some special settings. That's why I asked for the LGB # of the locomotive you're concerned with on the decoder settings.

Hi Thomas

I have been recommended to select DC capability OFF as we are 100% DCC and this layout will never use DC. The recommendation came after I had discussed a problem we have on initial power up. For some reason some Loco randomly start up and move with power up, usually the same ones but on say 1 power up in 5 or 6. We have to be standing by each time to turn the power OFF just in case. In all the problematic Locos the DC was selected ON, now OFF. Too soon to say if it has solved the problem.

Robin

 

[dunnyrail]

Hi Thomas

I have been recommended to select DC capability OFF as we are 100% DCC and this layout will never use DC. The recommendation came after I had discussed a problem we have on initial power up. For some reason some Loco randomly start up and move with power up, usually the same ones but on say 1 power up in 5 or 6. We have to be standing by each time to turn the power OFF just in case. In all the problematic Locos the DC was selected ON, now OFF. Too soon to say if it has solved the problem.

Robin

Interesting, I have a LGB U2 that sets off whenever power turned on. Must check to see if it is the same.

A small point re CV29, not all chips have the same selection of values. And certainly as in post #14 not all the values in the cv are 1’s. Though many of the values are appearing to say that.

Below are the values for a Massoth XLS. Note that 0 is “OFF” and Value as shown below is “ON”.

These are probably quite relevant to the original query.

What I failed to understand in my early DCC days was how the ‘bit’ thing worked, certainly the LGB wording and so called assistance from a so called computer expert just confused me.

You just need to know that if the value is negative in effect “0” then the value is ‘OFF’.

Thus a value of say 7 means that Bits 0,1 and 2 are ‘ON’. All the others are ‘OFF‘.

Reading an existing value thus means the requirement of some math. For instance a CV 29 reading of 49 would mean bits 0,4 and 5 are ‘ON’.

I would imagine trying to decode a CV29 value from the table in Post #12 could take some serious head scratching. Hence in some cases the use of a CV29 Calculator would be of great value, but hardly necessary for the Massoth example above.

My final,pint to note that the CV29 values for a LGB 55021 decoder are quite different to the Massoth XLS, thus it is quite imperative that you have the correct tables for the decoder that is being worked on.

 

[LGB333]

Hi Thomas

I have been recommended to select DC capability OFF as we are 100% DCC and this layout will never use DC. The recommendation came after I had discussed a problem we have on initial power up. For some reason some Loco randomly start up and move with power up, usually the same ones but on say 1 power up in 5 or 6. We have to be standing by each time to turn the power OFF just in case. In all the problematic Locos the DC was selected ON, now OFF. Too soon to say if it has solved the problem.

Robin

Robin - There's certainly no problem with the DC Operation "off" with only digital "on". But it's highly unlikely that with DC Mode activated in CV29 would cause your sound problem. It's more likely that the sound file is corrupted, or the decoder is defective. If the sound decoder is a Massoth such as the XLS or LS, you can reinstall first the firmware and then the sound file using a Massoth PC Programming Module to see if that fixes the issue. For example, last year I loaded for a customer the Stainz "Richter" sound file in a Massoth LS sound decoder that I was installing in his LGB Christmas Stainz locomotive. When I would activate the F2 Bell sound, a couple other F Key sounds would also erroneously activate at the same time......very annoying. I tried adjusting the CVs with those other sounds to no avail. So I reloaded the sound file and it did the same thing. I then informed Massoth's Hotline that their sound file was defective and instead then installed the standard Stainz sound file and all worked well.

If you can verify what the LGB # is and whether it has factory onboard electronics or a DCC Interface decoder installed in the locomotive, we'll all know whether it's Massoth decoder or an older LGB onboard decoder produced by Massoth. Then you can send a inquiry to the Massoth Hotline (hotline@massoth.de) asking for advice on solving your sound problem. Since Massoth produced the electronics for the original LGB company until their demise in 2006, Massoth should be able to assist you.

 

[Airbuspilot]

Jon and Thomas

Thanks for your inputs, I will have access to the layout again on Monday and try again. I’m not sure about the age of the Loco but with the LGB no presumably I can find out. At this stage working on sound is outside my current skill set, I think the decoder is Massoth and if so is there a CV to switch the sound OFF until I learn more?

Robin

 

[PhilP]

Jon and Thomas

Thanks for your inputs, I will have access to the layout again on Monday and try again. I’m not sure about the age of the Loco but with the LGB no presumably I can find out. At this stage working on sound is outside my current skill set, I think the decoder is Massoth and if so is there a CV to switch the sound OFF until I learn more?

Robin

If 'classic' LGB, then F8 or F4 may well turn off the sound. - Though this may not work if you then run it on DC.
There may be a volume control fitted 'somewhere'.. Knowing the model number, we may be able to point you in the right direction.

PhilP