It depends on what you're looking for really. Some things are fairly easy to figure out since they're the same value all the time. VIN# for instance was pretty easy to find within the mess of data because it is long string of known characters. I think I found that within a 15 second snapshot of the bus monitoring I did initially. Other things aren't so easy. I have hundreds of thousands of data points collected so far but only a few data packets deciphered completely.
Part of the reason for setting up a bench-top network is so I can easily monitor bus traffic while isolating certain modules. If I can tell which data packets are coming from which module (and possibly see where the packet is intended to go), I think I can work fairly quickly through the list. On one occasion I recorded about 25 secs worth of data while driving my van (on the high speed bus, remember there is also a medium speed bus in the van with lower priority data) and that resulted in just shy of 17,000 lines of information. For each line there is an identifier and 8 individual data values. In that 25 seconds, 28 unique identifiers were broadcast on the bus, each with at least one of the 8 values populated with something. Nothing just stands up and shouts out at you "HEY! I'm over here!"... you have to dig pretty deep and collect data a variety of ways in order to decipher what exactly is going on. Right now I'm communicating with modules individually to see what info they send out. I'll then introduce one module at a time and see how that changes things.
Not all of this module trickery is necessary for the Cummins installation. I could get away with a lot less work if I made some compromises. I want a very thorough understanding of the van's network and how everything interacts though. Most of what I'm doing here is just curiosity...and trying to find some business opportunities.
