[Ovmsdev] Power states clarification

[Greg D.]

Hi folks (mostly Mark, probably),

I just noticed that there is a power command for OBD2ECU as well as
ext12v.  I understand (or thought I did) what controlling the ext12v
power does, but how is "power" related to OBD2ECU?  Is this related to
firing up the opened CAN bus, or is there some tie to the ext12v power?

I have manually created scripts for vehicle.on and vehicle.off to
explicitly control ext12v, so that an attached HUD will follow the key. 
We talked about having this sort of thing done automatically, but I
didn't think it was ever implemented, nor what the particulars would be
regarding some of the device corner cases.  Is that what is happening here?

Related, what do the other states do?  (Sleep, deepsleep, etc.)

Thanks,

Greg