Digitrax DCS - All Locos on Layout Address Changed by Accident

[C855B]

Somebody here may know before I go into the wilds of the groups.io forums...

We had a club operating situation today where a smart but inexperienced operator somehow reprogrammed every decoder on the layout with the address he was pushing to his loco on the programming station. (We don't know, but it shouldn't matter, whether his loco was on the programming track or on the "test" operating track.) It's not possible, supposedly, to re-address in Ops Mode. Environment is a DCS240 plus DB100 boosters, DT402R and 402D throttles.

So how did this happen?

[mu26aeh]

I've done this too on my layout, but I'm not certain how I did it either.  Real PITA 

[mighalpern]

unless you programming track was not completely isolated.  i dont know,  internal short on the isolation switch perhaps.  Friend did this on his layout,  we isolated the rails and had a switch, but the toggle was not completely thrown
interesting to find out

[lyled1117]

The target locomotive may have been on the program track, but if he got into OPS 'broadcast' mode programming he could have programmed everybody on the main. I've done it. Try to safely move 40+ G-scale locomotives simultaneously with the same address to get them where you can reach them and put them on a program track. OUCH

Lyle D

[C855B]

Nope, programming track is totally separate, no switch. It's a setup we've been using for almost a decade, albeit with a DCS100 previous to the DCS240.

I was just told another member did the same thing several years ago, so this is not specific to the DCS240. But I'd still like to know how it can happen.

Apparently it happens often enough that some layout owners in our area who host operating sessions prohibit DT400 and -500 series throttles.

The target locomotive may have been on the program track, but if he got into OPS 'broadcast' mode programming he could have programmed everybody on the main. I've done it. Try to safely move 40+ G-scale locomotives with the same address to get them where you can reach them and put them on a program track. OUCH

That's currently my thinking, but Ops Mode is supposed to push to a specific address, and not broadcast. Is there a broadcast mode? I'm thinking Ops Mode to Address 0000 might work that way. If that's the case, it should be called "Oops Mode".

[railnerd]

That's currently my thinking, but Ops Mode is supposed to push to a specific address, and not broadcast. Is there a broadcast mode? I'm thinking Ops Mode to Address 0000 might work that way. If that's the case, it should be called "Oops Mode".

My friend has done this on his layout— ops programming to 0 is "oops" mode programming.

-Dave

[reinhardtjh]

That's currently my thinking, but Ops Mode is supposed to push to a specific address, and not broadcast. Is there a broadcast mode? I'm thinking Ops Mode to Address 0000 might work that way. If that's the case, it should be called "Oops Mode".

Yes.  In Ops Mode if you send the command to address 00, then all decoder respond.  So attempting to set the decoder address on the main and accidentally sending it to address 00 WILL reprogram every decoder connected to the main at the time.  So, yes, "Oops Mode" programming.

And also yes, that's why a number of operators only allow engineers to have UT4 throttles instead of DT100/300/400/500 unless they trust them a LOT.

[C855B]

Thanks, John. I also just read confirmation of this behavior in the Digitrax groups.io forum.

So mystery solved!

[C855B]

A footnote to this discussion - it has made a decision I've been wrestling with for a long while whether to have Digitrax duplex wireless on the big layout. The answer now is "absolutely not". There is entirely too much risk of somebody gumming the works given there could be as many as 50 to 60 locos on powered rails, not to mention countless decoders such as turnout servos and signal controllers hanging off the DCC bus. It would take days if not weeks to untwist hundreds of devices accidentally re-addressed.

I have been quite happy with JMRI and WiThrottle in daily operation for a little over a year, and upcoming controllers like the TCS Mini Throttle show promise as visiting operator solutions in the WiFi environment.

[Cajonpassfan]

My friend has done this on his layout— ops programming to 0 is "oops" mode programming.

-Dave

Oops mode? More like O'sh!t mode if you ask me...
Otto K.

[reinhardtjh]

Oops mode? More like O'sh!t mode if you ask me...
Otto K.

Depends on how many locomotives are on the layout and on a powered section.  1-5 might just be "oops".  50+ is an "OMFG what did I do?" moment.  Having something like JMRI with each of your loco's settings backed up would ease the pain slightly.  But it's still a matter of moving each loco/consist to a programming track to fix the damage.

*snip* not to mention countless decoders such as turnout servos and signal controllers hanging off the DCC bus. It would take days if not weeks to untwist hundreds of devices accidentally re-addressed.

Note that I *think* it's only mobile decoders.  I don't think stationary decoders should respond to an Ops Mode 00 broadcast.  But I haven't re-read the NMRA specs lately so I may be mistaken.

[peteski]

Yes, the OPS mode address 00 (broadcast) programming is part of the DCC specification, so all brands of decoders will receive and comply with those packets. Some decoder manufacturers provide decoder lockout against being accidentally programmed. I wonder of that lockout might have been helpful in this situation?

[reinhardtjh]

Yes, the OPS mode address 00 (broadcast) programming is part of the DCC specification, so all brands of decoders will receive and comply with those packets. Some decoder manufacturers provide decoder lockout against being accidentally programmed. I wonder of that lockout might have been helpful in this situation?

Probably for most people it would.  The ones that would have a problem are those that are frequently making and breaking consists.  They would have to remember unlock first, change the consist and then re-lock.  I'm not sure if there are other operations that would require on the fly Ops mode changes.

[djconway]

Yes, the OPS mode address 00 (broadcast) programming is part of the DCC specification, so all brands of decoders will receive and comply with those packets. Some decoder manufacturers provide decoder lockout against being accidentally programmed. I wonder of that lockout might have been helpful in this situation?

Decoder lockout would defiantly have helped in this situation.  Had a similar event on my old layout. I had an engine terminal track setup with a toggle switch for connecting as a programming track or as an operating track.  Well the inevitable loco bridging the gap happened and all but the 2 locos that I had locked became 7006.  Fortunately there were only a hand full of locos to re-address. 

[Ed Kapuscinski]

A footnote to this discussion - it has made a decision I've been wrestling with for a long while whether to have Digitrax duplex wireless on the big layout. The answer now is "absolutely not".

I wish Digitrax would come out with a new version of their DT100s. Or maybe a DT400L (for "light") that doesn't enable all of the dangerous stuff. Just throttle and switches.

I mean, you could always take the DT400s and do the "parents remote trick" of cutting all of the buttons they should never touch off flush.