Service Mode Decoder Lock

[Yampa Bob]

When first starting in DCC, I read about Bachmann decoders having a feature called "Service Mode Decoder Lock".  Since all my locomotives were Bachmann DCC on board at the time, I tucked the information away and never gave it further thought, until recently.

I usually have from 8 to 12 locos parked in the yards, and rarely remove any of them while programming a new decoder, and I don't have a programming track (yet). 

The other day I was changing the default address of my new Bachmann 44 ton, which was on the mainline.  Parked on my handy fiddle track was a Roundhouse Bumble Bee in which I had earlier installed a Digitrax DH123, set to address 9. 

Ok, some of you know what's coming, but save the guffaws and read on.

I changed the 44's address to 5, hooked up some cars and turned up the throttle a bit.  It worked fine, but the Bee also started moving down the fiddle track siding.  I thought "now, this is fun".  I removed the 44, reset the Bee to 9 and set it aside until I changed the 44's address.

The DH instructions have no reference to "decoder lock", it just states "all mode programming".  I repeated the scenario with another DH equipped loco, but it maintained its original address. 

My plan is to isolate the fiddle track for a separate programming siding.  (Another "roundtuit". )

For those who haven't read about the decoder lock, the EZ Command brochure has the warning note listed twice.
http://www.bachmanntrains.com/home-usa/ezcommand.php?ezpage=1

I found the event somewhat amusing, it proves DCC is never boring. 

[Jim Banner]

I could not confirm that any Bachmann decoders implement decoder lock, but all present production Digitrax decoders do.  Decoder lock is a way to allow you to program one of the decoders in a locomotive without affecting the others.  For a detailed explanation, click on the link below:

http://www.digitrax.com/v1/LOCK.htm

Note that CV15 & CV16 decoder lock is now listed as an option in NMRA  RP9.2.2

[Yampa Bob]

I checked the original datasheet for the affected DH decoder, it  was purchased about a year ago. The rest were purchased within the last 3 months.

To date I haven't had any defective decoders, which speaks well for the three brands I use. (Bachmann, Digitrax and Soundtraxx).

Due to some certain, and as yet unresolved, compatibility issues I only use Bachmann decoders (non-sound) in Bachmann locomotives/tenders. This avoids the issue of "Frick blaming Frack".

I would probably use more Bachmann decoders if they were available with JST plugs as standard or option. I read somewhere that the NMRA working group has the 8 pin socket/plug on their agenda, but don't know what the issue is about.

I was pleased that my AC4400 has both sockets on the board, I like having choices.

The subject of "standardization" is a bit off my original topic, but I would welcome any factual information or comments about this issue. As modelers, who keep the companies in business, I don't think we should request standardization, we should demand it.   

Please limit your comments to actual personal experiences with decoder compatibility issues, not rumor or hearsay.