“CTS goes low after a link level ACK has successfully been received from the next (link) level in the mesh (whether this being a Router or a Gateway), and is a positive acknowledge that the data in the buffer has safely been delivered to the next level of the mesh.
If no ack is received after depleting the configured number of retries, the router will attempt a new connection and continue trying to deliver the data until successful.
CTS will stay high until data has been successfully delivered to the next receiver. If the Max Packet Latency time has expired before the packet reaches the gateway, the packet will be discarded.
There is no end-to-end acknowledge when transmitting from a Router to a Gateway. If such function is required, it must be implemented by the external host, as e.g. a ‘Serial Out’ packet that is transmitted from the Gateway to the Router in question.
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Last Update: November 9, 2017