Release Notes
    
                         DSP-C Software
                       Version 2.04.0-c2
                            30SEP2022

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                            Contents
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    1.0 Release Description
    2.0 Change Log
    3.0 Known Issues

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    1.0 Release Description
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    Version 2.04.0-c2

    -- Release Date: 30 Sep 2022

    -- Replaces Version: 2.03.0-c0
    
    -- Release Artifact: nvtc_2_04_0-c2.hex (MD5: 078e2aa)

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    2.0 Change Log
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    ## v2.04-0-c2 (Released: 30SEP2022)

    --  Modified signal adjustment thresholds for DC current when 
        in Maintenance Override mode

        -- low threshold: 180 mA

        -- high threshold: 240 mA

    -- Modified excessive DC current threshold to avoid FOs as a 
       result of new signal adjustment thresholds when in 
       Maintenance Override Mode 

       -- threshold: 400 mA (at all signal levels)
   
    --  Ballast resistance is now reported in ohm-1000ft rather 
        than ohm-ft

    -- Modified occupancy detection logic in Maintenance Override 
       Mode when DC current is between 10 mA and 49 mA

       -- Now requires 3 consecutive FFT cycles in this range 
          before declaring an occupancy

    -- Now inhibits signal level adjustment when in maintenance 
       override mode and DC current is in the 'potentially 
       shunted' range

    -- Added reporting of current operating mode via management 
       port

       -- Added 'system.mode' property

    -- Added ability to set operating mode via management port

        -- "set" command now supports "system.mode" as a key

    -- Added reporting of current operating mode via diagnostic 
       port

        -- When in Maintenance Override Mode, an exclamation 
           point ('!') is appended to signal level in a 
           diagnostic mode record

    -- Added ability to toggle operating mode via diagnostic 
       port

        -- Default mode is Normal mode

        -- Mode toggle triggered by '**M' or '**m'

        -- Operating mode is stored in NV storage so that it 
           persists across resets

    -- Added ability to toggle RS422 termination resistor enable
       via diagnostic port

        -- State triggered by '**R' or '**r'

    ## v2.03-0-c0 (Released : 25MAY2022)

    --  Modified diagnostic streaming format to make it more 
        useful in diagnosing potential track circuit issues 
        (previous format was intended primarily for use by 
        development team in diagnosing DSP-C issues)

    -- Added system location to DSP-C configuration. 

       -- Location is reported via both management port and
          diagnostic port

       -- Location can be set via both management port and
          diagnostic port 
   
    --  Ballast resistance is now reported in ohm-1000ft rather 
        than ohm-ft

    --  Absolute value is now used when reporting DC current and 
        voltage via both management port and diagnostic port

    --  Fixed BQF bug when determined ballast current is zero
        (now reports ballast resistance at its max value rather
        than 0 when this occurs)

    ## v2.02.0-c0 (Released : 25MAR2022)

    --  AC_CURRENT_OFF_FREQ_EXCESSIVE condition no longer 
        results in a declared occupancy
        
        -- Condition still reported in status vector (via both 
           diagnostic and management port) 

    ## v2.01.0-c1 (Released : 01FEB2022)

    --  Reduce excessive DC current level for power levels other 
        than 0 to 200 mA (power level 0 uses a threshold of 300 
        mA)

    -- Modified occupancy LED drive logic to more closely track 
       the state of the output relay

    -- Added logging of sum of voltage/current in 'non-DSPC' 
       frequency bins (and 60 Hz bins) to diagnostic port

    -- Added logging of 60 Hz voltage/current bins to diagnostic 
       port

    -- Added support for retrieving sum of voltage/current in 
       'non-DSPC' frequency bins (and 60 Hz bins) via management 
       port API

    -- Added support for retrieving all voltage and current bins 
       via management port API

    -- Improved ballast quality factor calculation

       -- Use actual fundamental voltage rather than nominal 
          voltage

       -- Use more appropriate temperature coefficient of 
          resistance for steel

    -- Remove spurious management API output echo on the 
       diagnostic port

    ## v2.00.1-c1 (Released : 23JUN2021)

    -- Modified 'excessive DC current' threshold (was: 200 mA; 
       now: 300mA)

    ## v2.00.0-a0 (Released : 18FEB2021)

    -- First official production release

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    3.0 Known Issues
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    --  Diagnostic log records reported at signal level changes 
        show FFT bin values that are significantly different 
        than those reported at 'steady state'. This should only
        affect one or two records per level change.