Hello Guy, >> The Family/Address/IR field contains 3-bits of family code, 2-bits of >> address mode, 2-bits of IR (infrared) routing, and 1-bit unused. >> The 8 Legrand NITOO families are 000=CAD Filaire, 001=TopDog, 010=CAD RF, >> 011=CAD PLC, 100=CAD IR, 101=DLM, 111=escape, and 111=DLM Bootloader). >> This document only describes the DLM family. > > Are the fields following the Family/Address/IR field dependent on the family > code? Or can the rest of the packet, with the possible exception of the > opcode and payload, be parsed the same way regardless of the family code?
Yes, the fields following the Family code are dependent on the Family code. > Are the family codes dependent on the hardware being used? Yes, the Family codes are dependent on the hardware. The WattStopper DLM hardware uses a USB interface: http://www.wattstopper.com/products/digital-lighting-management/configuration-tools/dlm-computer-interface-tools-and-software.aspx and also tunnels the DLM packets in BACnet messages. Another Family is CAD PLC, part of Open-NITOO, but I don't know the hardware interface: http://www.myopen-legrandgroup.com/cfs-filesystemfile.ashx/__key/telligent-evolution-components-attachments/00-212-01-00-00-03-46-60/U3838B_5F00_Specifications.pdf >> The Opcode field contains the message command, which determines the Payload >> and Payload Length fields. > > Presumably the Payload Length field is the number of octets in the Payload > field. Yes, the Payload Length field is the number of octets in the Payload field. > Is there some other specification to which we can point for the values of the > Opcode field, and the corresponding payload, or can this be used for several > different families of opcodes (with the dissector presumably having to be > told which one to use)? (The spec doesn't have to itself describe the opcode > or payload values, although, if there's a spec or specs for them, references > to them might be useful.) I don't have a public specification for the Opcodes at the moment. Some are detailed in this Wireshark Lua dissector: http://kargs.net/captures/irb.lua >> The LRC Checksum excludes the Preamble octets. > > Does it cover the Dongle Code or Packet Delay field? The LRC does not cover the Dongle Code or Packet Delay or Preamble. Best Regards, Steve -- http://steve.kargs.net/ _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
