UDPIN and UDPOUT read or write a packet of data on the network using UDP protocol.
The IP address which the data is sent to or received from is designated by IPa.IPb.IPc.IPd eg. 192.168.0.122.
Broadcast addressing is not supported for UDPIN or UDPOUT.
The port is designated by PORT.
NODE PING - A special feature of ARMweb listens on port 49152 (0xC000) for any UDP broadcast.
The node will then reply with its Name and IP to identify it on the network.
According to iana.org, The Dynamic and/or Private Ports are those from 49152 through 65535.
User applications should use ports above 49152 to avoid other conflicts.
UDPOUT automatically sets the node to listen on the given port.
This allows any reponses to be buffered and subsequently read with UDPIN.
If an application wishes to just read UDPIN it is advised to call UDPIN once to clear any buffered data first.
Each call to UDPIN will wait up to one half second to receive data or return immediately upon receipt.
If no data was read the port is left open for reading, any incoming data will be buffered and available for subsequent calls.
The maximum size of the IOList is 127 bytes.