# Trace command notes The `trace` command lists the data exchange by the proxmark3 and a tag or a reader in human readable form. With `trace list` a table is shown which gives timing information, the src of the data bytes, the transmitted/received bytes itself, a check if the CRC was correct and some decoding of the command. To get a more detailed explanation of the transmitted data for ISO14443A traces the output can be converted to a pcapng file to read it with [Wireshark](https://www.wireshark.org/). To do so * use `trace list 14a x` * copy the output (starting with the timestamp) into a textfile * run `text2pcap -t "%S." -l 264 -n ` * now open your pcapng file in Wireshark or read it with the CLI version `tshark` An example frame with `trace list 14a`: ``` 19072 | 29536 | Rdr |93 70 88 04 cf ff bc 7f bb | ok | SELECT_UID ``` the same data with `tshark -r foo.pcapng -V -x`: ``` Frame 5: 13 bytes on wire (104 bits), 13 bytes captured (104 bits) on interface 0 Interface id: 0 (unknown) Interface name: unknown Encapsulation type: ISO 14443 contactless smartcard standards (177) Arrival Time: Aug 17, 2019 23:17:00.000002606 CEST [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1566076620.000002606 seconds [Time delta from previous captured frame: 0.000000840 seconds] [Time delta from previous displayed frame: 0.000000840 seconds] [Time since reference or first frame: 0.000001907 seconds] Frame Number: 5 Frame Length: 13 bytes (104 bits) Capture Length: 13 bytes (104 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: iso14443] ISO 14443 Pseudo header Version: 0x00 Event: Data transfer PCD -> PICC (0xfe) Length field: 9 Message: Select SEL: 0x93 NVB: 0x70 CT: 0x88 UID_CLn: 04cfff BCC: 0xbc CRC: 0xbb7f [correct] [CRC Status: Good] 0000 00 fe 00 09 93 70 88 04 cf ff bc 7f bb .....p....... ``` If the Wireshark ISO14443a dissector is missing some commands or needs some other rework please [file a bug](https://bugs.wireshark.org/bugzilla/).