View source for Version 5:Indexed CVs

==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, which are described in detail below. CV31 controls the high byte of the index/page and CV32 controls the low byte. Once the index/page has been selected, you can read or write the CV's within the indexed page just like any other CV. The indexed CV range is from CV256 to CV512 in all cases. This is possible through the paging system, wherein changing the values of CV31 and CV32 load new definitions for those indexed CV's, allowing them to be used for different applications based on the page.

This may be complicated to understand, so here is an analogy to help visualize what is happening. An analogy for indexed CV's is to think of a filing cabinet, where CV31 selects the "drawer" and CV32 selects the "folder" within the drawer. CV's 257 to 512 are then the "files" within those folders whose data you can read and write. All of the "files" within each folder and drawer are all numbered 257 to 512, but they all represent different things because they are in different folders and drawers. 

All indexed CV's can be 16-bit representations of data, be it bitwise, decimal-equivalent, or otherwise. This means that each "individual" indexed CV is made of tow 8-bit chunks, both of which should be read out to ensure accuracy. This can also be confusing if you are used to "normal" CV's where each read or write operation is only a singe step; whereas with indexed CV's, each read requires two operations, and each write could require up to two operations. 

In every case for TCS' decoders which support NMRA indexed CV's, the ODD numbered indexed CV's (257, 259, etc.) correspond to the LOW BYTE of the data, and the EVEN numbered indexed CV's (258, 260, etc.) are the HIGH BYTE of the data. A value of [1] in a High Byte indexed CV is equal to a value of 255+1 in a Low Byte indexed CV. This means that the maximum value of any 16-bit indexed CV is 65,535. TCS does not divide indexed CV's into 8-bits, so in the documentation below, the numbers listed for an indexed CV number use the High Byte. The low byte of the same CV is (''n''-1).

{{{{NAMESPACE}}:CV_31}}
{{{{NAMESPACE}}:CV_32}}

==Indexed CV Data Bytes==
Once values have been entered into CV 31 and CV 32, the decoder will select a "page" of data. ("Drawer" from the previous analogy.) This 'page' of data can be modified by using CV's within the range of CV 257 through CV 512. Depending on which values have been set in CV 31 and CV 32, the configurations which can be modified by CV's 257 through 512 will change. 

''Each configuration option'' will be represented within that particular page by a "High Byte" and "Low Byte," just like the CV's 31 and 32. CV's with an ODD number, such as 257, will be the Low Byte. CV's with an EVEN number will be the High Byte. Not all configuration options use both the high byte and low byte. For example, the DC Mode Bell Cutout Voltage is limited to values from 1 to 255 in the Low Byte CV. 

'''NOTE:''' Indexed CV's on this wiki and throughout our documentation will be referred to by their ''High Byte'' CV number, regardless of whether or not the high byte is used. 

===Example===
You want to change the speed of the locomotive at speed step 1 to be faster. To do this, you can program the Motor Speed Target for Speed Step 1 in the 128-Point Speed Table in the indexed CV's (Note: this table is more detailed than the 28-point "User Loadable Speed Table" defined in the standard CV range since it gives access to the speed at every speed step from 0-128 with no interpolation). The 128-point speed table is found in index 16.2, so set CV31 = 16, then set CV32 = 2. Next, you can read  CV258 and CV257 to do the current value. If the High Byte (CV260) has a value that is greater than 0, multiply that value by 256, then add the value of the Low Byte (CV259) to get the total for the current value. You could then repeat this process for reading the value of Speed Step 2 (Index 262) so that you do not exceed it. Finally, select a value between the original value for Speed Step 1 and the current value of Speed Step 2, and write the value into the CV(s) for Speed Step 1. 

Naturally, this process is tedious, and not for the feint of heart. Manual modification of indexed CV's does often require a lot of math. TCS is working to develop tools to make this process more user-friendly. Stay tuned! 
==List of Indexed CV's in Use==
''Specific Indexed CV numbers omitted from these tables can be assumed to be unused. To view details about the indexed CV, click on the indexed CV number to the left of the description.''

{| class="wikitable mw-collapsible"
|+NMRA Index 16.0
DC Mode Motor Control Settings (And Misc.)
!Indexed CV
!Description
|-
|[[Diesel Version 5:CV 16.0.258|16.0.258]]
|Startup Delay Timer
|-
|[[Diesel Version 5:CV 16.0.260|16.0.260]]
|DC Mode Bell Cutout Voltage - Regulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.262|16.0.262]]
|DC Mode Quill Delta - Regulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.264|16.0.264]]
|DC Mode Start Voltage - Regulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.266|16.0.266]]
|DC Mode Motor Hysteresis - Regulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.268|16.0.268]]
|DC Mode Max ADC Value - Regulated Supply Mode
|-
|16.0.270
|Reserved/Not Used
|-
|16.0.272
|Reserved/Not Used
|-
|[[Diesel Version 5:CV 16.0.274|16.0.274]]
|DC Mode Bell Cutout Voltage - Unregulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.276|16.0.276]]
|DC Mode Quill Delta - Unregulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.278|16.0.278]]
|DC Mode Start Voltage - Unregulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.280|16.0.280]]
|DC Mode Motor Hysteresis - Unregulated Supply Mode
|-
|[[Diesel Version 5:CV 16.0.282|16.0.282]]
|DC Mode Max ADC Value - Unregulated Supply Mode
|-
|16.0.284
|Reserved/Not Used
|-
|16.0.286
|Reserved/Not Used
|-
|16.0.288 to
16.0.290
|Reserved/Not Used
|-
|[[Diesel Version 5:CV 16.0.292|16.0.292]]
|Light Mapping - Auxiliary Input
|-
|[[Diesel Version 5:CV 16.1.257|16.1.257]]
|Bootloader Hash Part 1 (LSB)
|-
|[[Diesel Version 5:CV 16.1.258|16.1.258]]
|Bootloader Hash Part 2
|-
|[[Diesel Version 5:CV 16.1.259|16.1.259]]
|Bootloader Hash Part 3
|-
|[[Diesel Version 5:CV 16.1.260|16.1.260]]
|Bootloader Hash Part 4 (MSB)
|-
|[[Diesel Version 5:CV 16.1.261|16.1.261]]
|Bootloader Month
|-
|[[Diesel Version 5:CV 16.1.262|16.1.262]]
|Bootloader Day
|-
|[[Diesel Version 5:CV 16.1.263|16.1.263]]
|Bootloader Year
|-
|[[Diesel Version 5:CV 16.1.264|16.1.264]]
|Bootloader Version
|-
|[[Diesel Version 5:CV 16.1.265|16.1.265]]
|Bootloader Hardware
|-
|[[Diesel Version 5:CV 16.1.266|16.1.266]]
|Bootloader Processor
|-
|[[Diesel Version 5:CV 16.1.267|16.1.267]]
|Bootloader WOWPOW Protocol Version
|-
|[[Diesel Version 5:CV 16.1.268|16.1.268]]
|Decoder Serial Number Part 1
|-
|[[Diesel Version 5:CV 16.1.269|16.1.269]]
|Decoder Serial Number Part 2
|-
|[[Diesel Version 5:CV 16.1.270|16.1.270]]
|Decoder Serial Number Part 3
|-
|[[Diesel Version 5:CV 16.1.271|16.1.271]]
|Decoder Serial Number Part 4
|-
|[[Diesel Version 5:CV 16.1.272|16.1.272]]
|Decoder Serial Number Part 5
|-
|[[Diesel Version 5:CV 16.1.273|16.1.273]]
|Decoder Serial Number Part 6
|-
|[[Diesel Version 5:CV 16.1.418|16.1.418]]
|[Reserved]
|-
|...
|...
|-
|[[Diesel Version 5:CV 16.1.432|16.1.432]]
|[Reserved]
|}
{| class="wikitable mw-collapsible"
|+NMRA Index 16.2 
Motor Speed Targets (128-Point Speed Curve)
!Indexed CV
!Description
|-
|16.2.258
|BEMF Target - Speed Step 0/128
|-
|16.2.260
|BEMF Target - Speed Step 1/128
|-
|...
|...
|-
|16.2.512
|BEMF Target - Speed Step 127/128
|}
{| class="wikitable mw-collapsible"
|+NMRA Index 16.3 
Not Used (reserved)
!Indexed CV
!Description
|-
|16.3.258
|N/A
|-
|16.3.260
|N/A
|-
|...
|...
|-
|16.3.512
|N/A
|}
{| class="wikitable mw-collapsible"
|+NMRA Index 16.4
Sound Function Remapping
!Indexed CV
!Description
|-
|16.4.258
|Sound Mapping - Button 0
|-
|...
|...
|-
|16.4.314
|Sound Mapping - Button 28
|-
|16.4.316
|Sound Mapping - Random Sound #1
|-
|16.4.318
|Sound Mapping - Random Sound #2
|-
|16.4.320
|Sound Mapping - Random Sound #3
|-
|16.4.322
|Sound Mapping - Random Sound #4
|-
|[[Diesel Version 5:CV 16.4.324|16.4.324]]
|Sound Mapping - Auxiliary Input
|-
|16.4.326
|Sound Mapping - Reserved
|}
{| class="wikitable mw-collapsible"
|+NMRA Index 16.6
Lighting Modules (Part 1)
!Indexed CV
!Description
|-
|16.6.258
|Lighting Module 0 - Step 0 - Fade Rade
|-
|16.6.260
|Lighting Module 0 - Step 0 - Start Brightness
|-
|16.6.262
|Lighting Module 0 - Step 0 - End Brightness
|-
|...
|...
|-
|16.6.316
|Lighting Module 0 - Step 9 - End Brightness
|-
|16.6.318
|Lighting Module 1 - Step 0 - Fade Rade
|-
|16.6.320
|Lighting Module 1 - Step 0 - Start Brightness
|-
|16.6.322
|Lighting Module 1 - Step 0 - End Brightness
|-
|...
|...
|-
|16.6.376
|Lighting Module 1 - Step 9 - End Brightness
|-
|16.6.378
|Lighting Module 2 - Step 0 - Fade Rate
|-
|..
|...
|-
|16.6.512
|Lighting Module 4 - Step 2 - Start Brightness
|}
...Note.... As of 2-22-21, indexed CV's stop at 16.13.504 - Lighting Preset 16 - Step 9 - End Brightness
==See Also==

*[[Diesel Version 5:WOWDiesel Standard CV's|List of Standard CV's]]