[Mr. Adventure]

More than just communicate, the Honda generators have to be smart enough to make the power from unit #2 exactly match up to unit#1 in phase before the connection is made, and they have to keep their frequency exactly matched so that they can't fade in and out of phase with each other no matter what happens to the electrical load, engine horsepower, or anything else. This is critical in order to avoid significant and sudden electrical fireworks, by all accounts.

In my ancient Navy days, the electricians proved that 59.999 cycle power would work perfectly well for long periods of time running most things, even though it made ordinary electric clocks run slow by about 1 1/2 minutes per day (convincing them that my $2 clock was more accurate in this regard than the meter in their panel was more than a $2 task, as it turned out). At the time, I learned that this was why the power company had rules requiring the hard on-off switchover instead of letting them do the more graceful match up and fade in to/from ship/shore power. They probably use automatic Honda controllers today, maybe they just have faster fuses, or maybe they still have that rule.