Release Notes

                     DSP-C Software
                   Version 2.05.0-c0
                        12JUN2023

================================================================ Contents

1.0 Release Description
2.0 Change Log
3.0 Known Issues

1.0 Release Description

Version 2.05.0-c0

-- Release Date: 12JUN2023

-- Replaces Version: 2.04.0-c2

-- Release Artifact: nvtc_2_05_0-c0.hex (MD5: 8edbb0)

2.0 Change Log

## v2.05-0-c0 (Released: 12JUN2023)

 -- Reverted back to logging the actual polarity of the DC Current
      -- via RS232 diagnostic port
      -- via RS485 management port

 -- Invert DC current polarity so as to be consistent with legacy BNSF track circuits
 -- Only declare an unshunted track if the signed DC current exceeds the positive threshold. All DC readings less than the threshold are considered evidence of shunting

## 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

3.0 Known Issues

--  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.