There are a lot of ways in which tractors and implements talk. It would be nice if there were a ‘standard’ but for an industry so full of people that like things a certain way, tractor manufacturers don’t tend to be big fans of standards.
The first autonomous ‘tractor’ that we built included two separate networks, TCP/IP and CANBus. These were implemented for the ease of use of the guidance computer and controller being used by the system (both chosen by the client – we would use the controller again but not the guidance system). It allowed every intelligent device on the tractor to be used as a functional node. This was a very open system. That is, no matter who you were, if you knew the basic J1939 standards, and could do a little C programming, you could add a device to the node such as a fuel gauge.
There are no such easy systems in today’s commercial machinery. There are a lot of standards and many different technologies. Let’s examine Isobus standards for implements for example. We have: ISB, LOG, TIM, TC-SC, TECU, AUX-O and AUX-N, TC-BAS, etc. There are a lot.
To make things even more confusing you have significant incompatibilities. For example, AUX-O allows you to add additional control elements to a system (like a button for an system actuator or a control stick) but AUX-O is not compatible with AUX-N. They are similar but are of different ages much like OBD and OBD-II in the auto world.
There are a lot of options here but the hardest part is that they work on the lowest common denominator. So if one device on the network supports TIM but another doesn’t then you are screwed (that’s a technical term, not derogatory). So it is important to know not only what you want to accomplish, and how to put it together but how to take all of those elements and prepare them for what they might do in the future.
It’s a big job but it is what we have today and in the end it’s what’s most important to the farmer that matters most.
So why the picture of the dog? Because after all of this confusing tech talk it’s nice to end with something sweet and simple.