Re: QSI decoder in Atlas HO-gauge F-M Trainmaster - Would appreciate help in setting CV's


Hello DadnotGrandad,

  In order to access certain CV features you have to understand the QSI Indexing system.   It's not too difficult, so bear with me.

e.g.  From your example above:   CV55.73.0

 In the above example the CV 'group' number is 55 (my terminology).   The Primary Index number is 73 and the Secondary Index number is 0.

The primary index is accessed by programming CV49 (in this case to a value of 73).

The secondary index is accessed by programming CV 50 (in this case to a value of 0).

1/  In order to change the CV you must first Program On the Main (sometimes called Ops mode programming).

2/  You must then program the Primary and, if required, Secondary indexes.


3/  Finally you must program the 'group' CV.


 A very nice feature of the QSI decoder (version 7 and up) is the "Query" feature.   On the main, you can ask the value of any CV and the decoder will 'speak'.

  e.g.  In order to query the value of our above example CV55.73.0, you

1/ Program On the Main.  

2/ Program the Primary and Secondary Indexes.

3/  Program CV 64 to whatever CV 'group' you want to query (in this case CV 55)   CV64=55.

  The decoder will tell you what is the current CV value.  I highly recommend you do this first, for each of the CVs you wish to change.  Write the results down on a piece of paper.

  Pages 163 - 172 instructs the user how to configure the Reverse Head Light (including the the dimmer brightness and ramp up/down rates (speed at which the headlight assumes full brightness or dims)) if you choose.   CV55.73.0 = 0 is just basic ON/OFF control.

  Pages 119 - 126 refers to what configuring what you want controlled by a specific Function button.

Good luck and get Decoder Pro.  ;-)


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