Some have OBDII like a standard passenger vehicle would. Some don't. Some have one of two different types of plugs that support the J1939 standard - there's a 7-pin and a 9-pin IIRC. https://en.wikipedia.org/wiki/SAE_J1939 Some have OBDII as well as a separate J1939 plug. The wiring in each plug is standardized but there is no one standard across all heavy duty vehicles. We used Mitchell's Truck Series when we had to build up a database of which vehicle had which plug.The purpose was to know if the vehicle had an OBDII port or if it required an adaptor to be able to plug an OBDII device into one of the J1939 ports. https://truck.prodemand.com/ For connecting one device in one vehicle permanently you could also just hardwire into the wiring behind the OBDII or J1939 port. - Chris Pearson On Mon, Nov 13, 2017 at 8:51 AM, Bob Blick wrote: > Is there any standardization of the connectors used in heavy truck CAN > bus? For instance, if I have a device that needs to be permanently > connected in the vehicle, what are my options as far as connecting to the > vehicle's bus? I don't want it to physically interfere with maintenance a= nd > diagnostics of the vehicle. > > Thanks, > > Bob > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .