Fallback to dumb mode

[ranzbak]

(X minutes green #1, Y minutes red #1 and #2, X minutes green #2 ...) on central comms or sensor failure

I would suggest both lights starting to blink orange, since we don't know the state of the other light if we lose communication, and we don't want the legal responsibility when both lights turn green at the same time.

[Stoneshop]

There are two comms failure modes:

• loss of comms to central controller, but designated partner (see Location req) is reachable -> run in dumb/timed mode. One unit should act as timer master
• total loss of comm -> blink orange (pattern TBD)

[ranzbak]

I was thinking about having a clocked mode for traffic light operation indeed, this is also most robust.

The loss of comm and total loss of comm needs to be defined though, because I don't know what 'total' means :-)

[Stoneshop]

total == loss of comms to central controller AND loss of comms to designated partner. Seeing other nodes is irrelevant, except as an indication that the failure is not local. But functionality to operate as a pair or under control of the central node is impossible. This also applies to control by the portable aux controller (when implemented).

In case the designated partner is down but the central controller is reachable, the c.c. could implement a strategy to operate the remaining nodes to still maintain sufficient overall control, but this is beyond scope.