Unicast addressing

When devices transmit using DigiMesh unicast, the network uses retries and acknowledgments (ACKs) for reliable data delivery. In a retry and acknowledgment scheme, for every data packet that a device sends, the receiving device must send an acknowledgment back to the transmitting device to let the sender know that the data packet arrived at the receiver. If the transmitting device does not receive an acknowledgment then it re-sends the packet. It sends the packet a finite number of times before the system times out.

The MR (Mesh Network Retries) parameter determines the number of mesh network retries. The sender device transmits RF data packets up to MR + 1 times across the network route, and the receiver transmits ACKs when it receives the packet. If the sender does not receive a network ACK within the time it takes for a packet to traverse the network twice, the sender retransmits the packet.

If a device sends a unicast that uses both MAC and NWK retries and acknowledgments:

• Use MAC retries and acknowledgments for transmissions between adjacent devices in the route.
• Use NWK retries and acknowledgments across the entire route.

To send unicast messages while in Transparent operating mode, set the DH and DL on the transmitting device to match the corresponding SH and SL parameter values on the receiving device.