DCC Sniffer

Packet Analyzer

    This software allows for a complete tracking of all commands on the rails as well gives sophisticated trigger features to capture only special events. Local LEDs provide a quick overview of the status and and actual DCC commands.

    Every received DCC command is decoded and reported to the host either in a hex format or a readable text string (or both). The reported data can be restricted to special types of command (like 'report only command for accessory decoders'). Additionally, it is possible to extend the selection for certain subtypes and addresses. EG it is easily possible to log only speed command to a certain (or some) locomotive.

    Moreover, it is possible to add a timestamp (with 1ms resolution) to the reported commands, thus giving a powerful analysis tool for the performance of command station and railraod pc software.

    Additionally, it is possible to recording a separate trigger event. Thus, the overall response time from the sensor event until the corresponding reaction of a whole system could be measured.

    The DCC Sniffer is connected via USB to the host. A high speed serial link (115200 Baud) is established on this USB connection, giving enough bandwidth to transport all the decoded information.

    The software emulates the NCE Packet Analyzer plus a lot of additional, very useful features. This analyzer is easily controlled by short commands.See the command list for more details.

The LEDs and their meaning

    Control LEDs
    •
    LED1, green
    ON
    in normal operation:
      on/off: unit broken
      blinking (1Hz): regular operation
    during bootloader:
      permanently on: regular operation
    •
    LED2, blue
    GO    		 This LED indicates the enable status of the sniffer. Pressing the button or sending a blank command will toggle the enable status.
    half on: Sniffing enabled
    highlighted pulse: Message sent to host.
    off: Sniffing disabled
    •
    LED3, green
    LOC
    off: no locomotive packet detected
    highlighted pulse: locomotive packet detected and reported.
    dimmed pulse: locomotive packet detected but not reported, since either the tracker is disabled or not matched.
    •
    LED4, green
    ACC
    off: no accessory packet detected
    highlighted pulse: accessory packet detected and reported.
    dimmed pulse: accessory packet detected but not reported, since either the tracker is disabled or not matched.
    •
    LED5, orange
    RC    		 This LED indicates the presence of railcom and the polarity of the DCC signal
    - - - - - X: (short flashes) 'red' side of the track is on the other side of the pcb (near ON LED)
    X X X X X -: (short breaks) 'red' side is on this side of the pcb.
    - - - - X X: (blinking, more off) 'red' side is on this side of the pcb + railcom detected
    X X X X - -: (blinking, more on) 'red' side is on this side of the pcb + railcom detected
    •
    LED6, orange
    PRG
    off: no service mode packet detected
    highlighted pulse: service mode packet detected and reported.
    dimmed pulse: service mode packet detected but not reported, since the tracker is disabled.

PC Output


    Screenshot of output (during accessory command, shown: turnout 6 coil on and off)