Hmm.. so continuing on my investigation of the idea Mike Innovative McGinnis mentioned, using a CAN bus interface for all of the data collection and transmission. That would allow me to use an aftermarket logger (Motec, RaceCapture, etc). The fastest supported CAN speed in most of these products is 1Mhz. A normal extended CAN packet is 128bits, plus 3 interframe bits. Since CAN is NRZ, it has to do padding with long strings of zeros, so worst case packet size is 140 bytes plus 3 interframe bits. A packet transmits 8 bytes, so for simplicity assume that is 4 sample channels. For 24 channels I would need 6 frames. At 1 MHz you could get a theoretical framerate of 6993 frames per second, which would be 1165 samples/sec. Piratical limits would be less then this.

This can work, but is really close to the limits of CAN. I have doubts that any of the loggers can handle data at that rate as well. I could lower overall capture rates to either 500hz or 100hz, and certainly things like temp sensors don’t even need that high of a datarate. Perhaps I’ll create three classes of capture channels and set the rates accordingly. The real question is what type of CAN messages can these guy decode? Can you specify MSB/LSB, Conversion factors? Up next are some question to Motec and a few other vendors.