Darrel-
I have studied the J1708 and feel I understand how it works and how I can use it for my own applications. My question (at least for now - grin) is there should be no limitation of 20 devices IF I use 1/4 or 1/8 loading 485 transceivers = correct? The 20 device load was designed when they were heavier on the line I am guessing?
I also plan on using 57.6k as my speed thus making my bit time 17.3 us for a total bus idle time of 173 us - also shouldn't be a problem?
Won't be using any PIDs but the MIDs will just be the address on the network - lower numbers get higher priority on arbitration.
I did also like the message delay priority - might try to use that!
Lastly, probably use just a simple checksum without the inversion and add 1 - don't think I need it.
Have you used this for something other than trailers?
Regards,
Steve