Phil,
Not knowing your level of experience with these I apologize in advance if I am either too detailed or too simple.
I will share the following based on what I went through with the hope that it may help.
I have a 65000 sound unit controlled by a 55015. I have a 55021 decoder in a loco and I have set the Loco's address and the 65000's address to the same value.
If I understand your reply above, you are now most concerned about a 55021 decoder in a loco with a sound board on the loco that is part of the loco.
Not owning any locos with on-board sound, the first question I have is, "does the sound board on the loco have its own address?
If no, than I assume when you select the loco's address you should be able to use F8, assuming the board uses F8 as the on-off.
If yes, i.e. the soundboard has its own address, then you would have to select that address with your controller (55015p for me) as if it were a loco and then use F8.
Alternatively, you could change the address of the sound board to the same address as the loco and then when you select that address you would be sending signals to the sound board and the loco simultaneously and therefore F8 should work.
I had a odd occurrence with my set-up that is worth sharing and may provide insight. The net of it is that the instruction manuals they provide are not always reliable.
I have a 55021 in a loco. I also have a 65000 sound unit that I have set its address to the same address as the loco. The 65000's sounds respond to buttons 1,2,3,4,5,6, and 8 (7 is blank) according to the 65000 Manual. However, in reality it responds to 1,2,3,4,7,8 (6 is blank)
I had gone back and forth with a Massoth/LGB rep in Germany to try to get the unit back to the factory setting such that 1,2,3,4,5,6,8 controlled the sound with the proper assignments for each button. We were unable to get it to work. We changed all kinds of CV settings with all kinds of results. We did resets many times. He had no good explanation other than I might have an new or older version of the unit and he could not tell.
Having said this, I accepted that the unit worked with the new button assignments and that button 6 was blank. I then tried to change the button assignment on the 55021 for controlling the F1 output. The idea was to use button 6 to turn F1 on and off so as to control the smoke stack which was wired to the F1 output.
The 55021 manual says the CV51 has a value that designates which button controls the F1. According to the manual, a value of 13 in CV51 causes Button 6 to control the F1. I found this untrue. I took a guess and set the value to 14 and that caused Button 6 to control the F1 output. According to the manual, a value of 14 should cause Button 7 to control F1.
My point in all this is that some of this seems to be hit or miss or at best, it is just poor documentation.
So back to your situation, I would look for a manual on the sound board that show's it CV settings and the manual on the loco that shows its CV settings. I would then look at the CV51 settings on the 55021 and see what you can work out.
I am sorry this is not a precise solution. I share the frustration you have with this. Please know that the frustration we all have is why we all do this. It is like smashing your finger in the car door. It feels so much better than the everyday frustrations in life. As the one fellow said in one of the posts, we can vent our worries with booze or with CV values. LOL.
Cheers for a Happy New Year.
John
Pennsylvania, USA
