How long does programming last with power off?

[selector]

I have never had a decoder lose anything more than its chuff rate setting over the three years of model railoading.  None have lost their momentum/inertia, bell rate, whistle type, volumes for all of the sounds, or address.  The Tsunami decoders seem to need chuff rate tweaking, but not my QSI decoders.

[60YOKID]

I've had decoders loose their memory on several ocassions.  It seems to happen more often after a derail or track short circuit episode.  My guess is it happens because of the electrical impulses that a short circuit can produce.  Some decoders are more suseptable to this than others, and dirty wheels might also be a factor.

[jamnest]

Sonetimes my decoders get "scrambled" and need to be reprogramed.  I just put them on the programing track; fire up Decoder Pro; call up the locomotive file and send the saved decoder information back to the decoder.

One of the many benefits of Decoder Pro, which can be downloaded free.  You must, however, have a DCC system that has a computer interface.

JIM

[retsignalmtr]

i have three locos that have lost their 4 digit addresses and would not run until reset to factory the factory default settings with the magnetic wand then reprogramed with the cab number. they are 2 ho proto rs 27's and an atlas mp 15. this has happened while operating and also while on track but not selected to run. all three have sound. i have many locos in ho and n scales but it has only happened to the three with sound. it has also happened to members of my club but only with their sound equiped units. all of my other locos have kept their addresses for several years now.

[CSX Robert]

The memory that stores the programming is called flash memory.  It does not require a battery to maintain the memory and it should last forever with the power off.

[Maurice]

If I understand it correctly, when I first put a DCC locomotive on my layout, I have to program it.Once it is programmed, is there an internal battery to retain the memory?