The directed node discovery command (ND with an NI string parameter) sends out a broadcast to find a node in the network with a matching NI string. If such a node exists, it sends a response with its information back to the requesting node.
In Transparent mode, the requesting node outputs an extra carriage return following the response from the designated node and the command terminates; it is then ready to accept a new AT command. In the event that the requested node does not exist or is too slow to respond, the requesting node outputs an ERROR response after N? expires.
In API mode, the response from the requesting node will be output in API mode and the command will terminate immediately. If no response comes from the requested node, the requesting node outputs an error response in API mode after N? expires. The device's software assumes that each node has a unique NI string.
The directed node discovery command terminates after the first node with a matching NI string responds. If that NI string is duplicated in multiple nodes, the first responding node may not always be the same node or the desired node.