Timing and retries

Node-bus timeout targets

The protocol assigns these master-side limits:

Operation	Timeout
Standard command	10 ms
Ping	400 µs
Flash or firmware upgrade	3 s

After a timeout the master retries according to its policy; after retries are exhausted the node is treated as unavailable. These are RS-485 transaction targets. Ethernet transport adds its own UDP timeout and retry layer.

Responsiveness

Nodes should answer ordinary requests promptly and must not keep interrupts disabled for long periods. Firmware should return a ping ACK within 100 µs. Long flash operations are the explicit exception and therefore have their own timeout class.