CV 29 Uncovered....
This CV contains the basic configuration settings for the decoder. Using our manual that came with the decoder, go to table 1 and follow the rows. (A,B,C,D,E)
- If you want the locomotive to run in the “default” direction Row A receives a value of zero. - If you want to reverse the direction that the locomotive is running Row A receives a value of 1. - If you want the decoder to be in 14 speed step mode Row B receives a value of zero. - For 28/128 speed step mode Row B receives a value of 2. - To disable analog operation Row C receives a value of zero. - To enable analog operation Row C receives a value of 4. - To deactivate loadable speed tables Row D receives a value of zero. -To activate loadable speed tables Row D receives a value of 16. -To address the locomotive using CV1 (address 1-127) Row E receives a value of zero. -To address the locomotive using CV17 and 18 (Address 128 or higher) Row E receives a value of 32.
Select the values for the features that you want and add them all together. For example – the decoder comes with the default value of 6 in CV29. This is because in row A we want the locomotive to run in the default direction, so we have a value of zero. In row B we want 28/128 speed step mode so there is a value of 2. In row C we want analog operation enabled so there is a value of 4. In row D we want the loadable speed tables deactivated so we have a value of zero. Lastly, in the row E we want the decoder to use CV1 (1-127) addressing. When you add all of those values together you get the default value of 6. There is a very important factor that is worth explaining about row C in table 1 for CV29 – when analog mode is disabled (a value of zero in row C) the decoder will not work in DC (analog) mode!!!!!! (This means that when you set your locomotive on a DC layout it will not run.) The reason for disabling analog mode is that when DCC was first introduced there were a lot of problems with electrical noise. This would cause the decoder, when on a DCC layout, to think that it was on a DC layout so it would either run away or stop running. Analog operation can be disabled in CV29 to avoid this problem. Nowadays, DCC has been perfected to the point that this is mostly unnecessary. However, if you are running on a large layout (100 engines or more) there may be a sufficient amount of noise to warrant disabling the analog (DC) operation.
Example 1# We decide to use loadable speed tables and make the engine run in the opposite direction (because the orange and the gray motor wires were switched during the installation) and also use four digit addressing. We do not want to change the default values for row B and C, which means that the locomotive will still use 28/128 speed steps and will have DC operation enabled. To do that we should put the following values into CV29:
Row A value of 1 (direction reversed) Row B value of 2 (speed step 28/128) Row C value of 4 (enable analog mode) Row D value of 16 (make the loadable speed tables active) Row E value of 32 (address higher than 128 is being used) CV29 value of (1+2+4+16+32) = 55