VS1x Firmware Versions
*****************************

001.001 
- first version

001.002
- activation of firmware update via USB conmmand
- load defaults command sets a pyramidal limit curve for FFT
- overload indication by four red LEDs

001.003
- alarm relay response time for peak monitoring reduced to 
  <100 ms 

001.004
- teach-in function fixed, new alarm limit becomes effective  
  immediately instead after restart
- delay time between power-on and LED/relay alarms was not   
  determined after supply connection, sometimes longer waiting
  time