yes, used endianness is always big endian. before version 1.2 of gencp standard, exist the possibility to define a protocol endianness - but this is removed with version 1.2! so all endianness of protocol data of cameralink interface should also be big endian.
the protocol transports read and write memory request between host (pc with frame grabber) and a camera. the data in this requests can be little and big endian in mixed manner ! but this is defined in the next layer the SFNC standards of the xml description files of the camera. what do you mean - makes it sense to define a DLT_request for the CameraLink Protocol ? Best Regards Rene Weber Geschäftsführer: Dr. Albert Schmidt· Dr. Oliver Vietze Sitz der Gesellschaft: Radeberg Amtsgericht Dresden: HRB 15379 Ust. ID: DE 189714583 -----Ursprüngliche Nachricht----- Von: Guy Harris [mailto:g...@alum.mit.edu] Gesendet: Freitag, 13. Januar 2017 21:21 An: Weber René Cc: tcpdump-workers@lists.tcpdump.org Betreff: Re: [tcpdump-workers] DLT_request On Jan 13, 2017, at 6:49 AM, Weber René <rwe...@baumer.com> wrote: > On Jan 11, 2017, at 11:42 PM, Weber René <rwe...@baumer.com> wrote: > >>> We working at software for industrial cameras which are supported by the >>> cameralink standard. We use Wireshark to monitor the control interface. We >>> have implemented a solution similar like the u3v dissector and uses link >>> type DLT_USER0. The cameralink interface is basically a serial interface >>> like rs232 uart. > >> So this is for GenCP over a serial port, rather than GenCP-over-UDP? > > I don't know a GenCP-over-UDP - where can I find some information about this? OK, they mentioned UDP here: http://www.emva.org/wp-content/uploads/GenICam_GenCP_1.2.pdf but they didn't really mention it as a transport. >> So do the packets in such a pcap or pcapng file start with the serial prefix >> described in section 1.5 "Serial Prefix", followed by the common command >> data described in section 4.3 "Common Command Data", followed by the >> specific command data for the command in question (section 1.6 "Serial >> Postfix" says there's no postfix for serial ports)? > > correct. U3V in opposite to cameralink has a different prefix and a different > endian order. So the GenCP-over-serial endianness is big-endian, as per Appendix 1. Serial Port Implementations This section specializes the generic protocol for the use over a serial link. 1.1. Byteorder For devices communicating over a serial link the byte order of bootstrap registers and protocol fields is big-endian. _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
