skargMSTP Capture Tool This tool captures MS/TP packets on an RS485 serial interface, and saves the packets to a file in Wireshark PCAP format for the MS/TP dissector to read. The filename has a date and time code in it, and will contain up to 65535 packets. A new file will be created at each 65535 packet interval. Here is a sample of the tool running (use CTRL-C to quit). D:\code\bacnet-stack\bin>mstpcap COM3 38400 Adjusted interface name to \\.\COM3 mstpcap: Using \\.\COM3 for capture at 38400 bps. mstpcap: saving capture to mstp_20090729123548.cap 1400 packets MAC MaxMstr Tokens Retries Treply Tusage Trpfm Tder Tpostpd 0 0 525 0 32 0 0 0 0 1 127 525 0 16 79 0 0 0 MS/TP capture tool also includes statistics which are listed for any MAC addresses found passing a token, or any MAC address replying to a DER message. The statistics are emitted when CTRL-C is pressed, or when 65535 packets are captured and the new file is created. The statistics are cleared when the new file is created. MaxMstr = highest destination MAC during PFM Tokens = number of tokens transmitted Retries = number of second tokens sent to this MAC Treply = max milliseconds it took to reply with a token after receiving a token Tusage = max Tusage_delay in milliseconds based on PFM and subsequent token Trpfm = max milliseconds to respond to PFM with RPFM. Tder = max milliseconds to respond to DER request with DNER Tpostpd = max milliseconds to respond to DER request with Reply Postponed.