On Oct 11, 2006, at 3:28 PM, Bdale Garbee wrote:On Wed, 2006-10-11 at 09:41 -0700, Louis McFadin wrote:One of the ways we planned to manage the system is to have deadbands on the buss voltage. Another way is to have a simple way that the units can communicate to each other as to their state.As we've discussed, this all needs to be designed very carefully, and deserves careful review by a broad team. Adding another bus of some type to pass state information around between the various power management devices seems attractive, but the more I've thought about it the more I think we should try to minimize the amount of shared state information and complexity. If we can do it all with voltages on the DC bus and suitable dead band definitions, that seems like a big win to me. I'm certainly open to being convinced otherwise, though!I am with you on this. However I also believe it's good to have additional data exchanged between the units.I have also been thinking of using a common system such as the IHU to send out a number which is it's opinion as to the voltage of the bus.That's an interesting thought. The immediate difficulty I see is how all these devices would be connected to the IHU... putting a CAN controller on each certainly seems to be driving the complexity equation the wrong way, and yet we really don't have any other communications path to/from the IHU. Perhaps some intermediate flavor where there's an overall power management controller coordinating all these little devices and interacting with the IHU makes sense, but keeping each of the little units completely independent may be lower risk overall? BdaleI am thinking the we may need to have a power control module just for that purpose. There needs to be some way for the IHU to communicate with the power system even if we make it start up autonomously.