Difference between revisions of "CV 15"

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m (revised - in V4 a decoder will nack a read operation. In V5 the value will read out but cannot be written to. I have fixed this.)
 
m (1 revision imported)
 
(No difference)

Latest revision as of 21:47, 16 July 2021

CV 15
Decoder Lock (Key)
Range of Values0-7
Accepted Values0-7
Default Value2

NMRA CV 15 - Decoder Lock (Key)

The Decoder Lock feature is used to change CVs in only one of several decoders with the same short address (CV1) or long address (CV 17 and CV 18). Typically this becomes a concern only when multiple decoders are installed in the same locomotive. An alternative reason to use Decoder Lock is if you fear that another person may attempt to program your decoder on accident (or on purpose), and you want to prevent that from being possible.

The WOWSound Version 5 decoder includes an exclusive new feature which will play an audible warning if you attempt to program a CV while Decoder Lock is active.

To Lock a Decoder:

  1. Program a number between 1 and 6 into CV 16 in each decoder (see the chart below for the standard values) before the decoders are installed in the locomotive.
  2. Set CV 15 to a value which does not match CV 16, or use a value of 7 to ensure the decoder is locked.
  3. The decoders will individually compare CV 15 to CV 16 and, if the values are NOT equal, the CV values of that decoder may NOT be manipulated.

To Unlock a Decoder:

  1. To change a value in another CV of one of the installed decoders, first write the corresponding number into CV15 which matches the value in CV16 for the decoder you wish to program.
  2. Set CV 15 to a value which matches the CV 16 value for the decoder you want to program. You may also use a value of 0 in CV 15 if you want to program all of the decoder simultaneously.
  3. The decoders will individually compare CV 15 to CV 16 and, if the values are equal, the CV values of that decoder may be manipulated.

Important things to know about decoder lock:

  • By default, a DCC decoder will be unlocked, but may or may not have a value set in CV16. The Value in CV15 must be equal to CV16 in order to read or write CV values.
  • If Decoder Lock is active, only CV15 and CV16 can be manipulated When a decoder is locked, all CV values other than CV15 and CV16 may report "NoAck" or similar on your Command Station when writing, but should read back their expected values.
  • If the values in CV15 and CV16 are different, the decoder is considered locked, and programming request will be ignored.
Decoder Type Key #
Unlock All Decoders 0
Unlock Decoder #1 1
Unlock Decoder #2 2
Unlock Decoder #3 3
Unlock Decoder #4 4
Unlock Decoder #5 5
Unlock Decoder #6 6
All Locked 7