Diesel Version 5:WOWDiesel Indexed CV's
Contents
Overview
Indexed CV's use a Paging System to allow for the ability to program thousands of CV's. There are two index CV's used to select an indexed page, CV31 and CV32. CV31 controls the high byte of the index and CV32 controls the low byte. Once the indexed page has been selected then program the CV just like any other CV.
An analogy for the paging system is to think of a clock, CV31 controls the hour, CV32 controls the minute, and then the actual CV is the "second".
| Indexed CV High Byte | |
|---|---|
| Range of Values | 16-255 |
| Default Value | 16 |
NMRA CV 31 - Indexed CV High Byte
The Indexed Address is the address of the indexed CV page when the decoder is set up for indexed CV operation. CV#31 contains the most significant bits of the two byte address and may have any value between 16 and 255 inclusive. Values of 0 thru 15 are reserved by the NMRA for future use. CV32 contains the least significant bits of the index address and may contain any value.
This gives a total 61,440 indexed pages each with 256 CV's in each page for a total of 15,728,640 indexed CV's!
(High byte 240 * Low Byte 256 * bytes per page 256) = total number of available CV's
See Indexed CV's for more info on using this CV
| Indexed CV Low Byte | |
|---|---|
| Range of Values | 0-255 |
| Default Value | 0 |
NMRA CV 32 - Indexed CV Low Byte
The Indexed Address is the address of the indexed CV page when the decoder is set up for indexed CV operation. CV31 contains the most significant bits of the two byte address and may have any value between 16 and 255 inclusive. Values of 0 thru 15 are reserved by the NMRA for future use. CV32 contains the least significant bits of the index address and may contain any value.
This gives a total 61,440 indexed pages each with 256 CV's in each page for a total of 15,728,640 indexed CV's!
(High byte 240 * Low Byte 256 * bytes per page 256) = total number of available CV's
See Indexed CV's for more info on using this CV
Example
If you want to change the speed of the locomotive at speed step 1 you can program the Speed table in the indexed CV's (this table is more detailed than the "28 speed step User Loadable Speed table" as it gives access to the speed at every speed step 0-128).
The CV for Speed step 1 has two parts, indexed CV 16.2.258 and indexed CV 16.2.257
So set CV31=16, then set CV32=2, then you can read or write CV258 and CV257 just as you would any other CV. In this scenario CV258 is the coarse adjustment and will have a larger effect on the speed that CV257 which is the fine adjustment.
| Startup Delay Timer | |
|---|---|
| Range of Values | 0-65535 |
| Default Value | 1000 |
CV 16.0.258 - Startup Delay Timer
Two byte CV (257:258) - defines the maximum delay time (in milliseconds) the decoder will wait and look for a non zero DCC speed packet when powering up. During this delay no sound will be played.
If the decoder sees a non zero speed packet during this time it will skip the startup sound and go right to playing the engine sound
This is useful in cases where the engine was moving along and hits dirty track and resets.
If the delay time is large and the startup sound still plays consider adjusting the command stations stack so that speed refresh packets are sent more often.
See Indexed CV's for more info on using this CV
