DCC Sniffer


    DCC sniffer is a probe for DCC, based on Atmega162 (Atmega8515 will fit as well). It is connected to the USB Port of an PC and buspowered. The DCC side is connected through an optocoupler. An additional trigger input (also with optocoupler) and the connection for an IR sensing device is provided. The board comes with an JTAG header, a 6 pin bootheader (Atmel standard). This bootheader is also accessible from the USB chip. There is one tracer and 6 LEDs for status.
    The board is completely in SMD and 64 * 24mm sized. This size is suitable to be mounted inside a tic-tac box.
    The processor enables sophisticated trigger and debug features for DCC, much more advanced than ShowDCC. DCC sniffer includes such features like DCC polarity checker, railcom detector and response time measurement.



    After connecting the board to the USB, the operating system show up a new serial port named DCC sniffer. Attach a terminal program to this port (baudrate 115200, 8 bits, no parity, 1 stop (=8N1)). Now you should be able to issue commands to the sniffer. Start with '?' to ask for version and help.
    There are different application for the board, these require different software and probably different components on the board.
  • DCC sniffer:
    Data on the tracks is recorded and decoded and fed through USB to an connected host. The data is transmitted as raw hex and/or fully decoded in plain text. Numerous trigger features enable a comfortable evaluation of the DCC signal. Together with the additional trigger input the delay from a sensor event until the expected DCC signal could be measured.
  • DCC quick tester:
    stand alone tool - just hold it on the tracks - the LEDs will show the types of DCC command currently on the track, the polarity and whether railcom is activated.
    This is the same software as the sniffer, but requires an additional voltage regulator. (option 4)
  • Xpressnet Logger:
    This software traces xpressnet® messages.
    An additonal RS485 tranceiver is required.
  • DCC Decoder Tool:
    Trace the reaction (i.e. speed change) of a decoders after a DCC command.


Using the gateway board as sniffer