Takes the data in the CALCnet receive buffer and outputs it into its appropriate variable.
Retrieves the pending packet, if any, from the CALCnet buffer, and clears it.
If the packet contains a list, it is loaded into LCN2 (a list automatically created by Cn2Get when it finds a pending packet ready for processing.)
If the packet contains a string, it is loaded into Str9.
An integer is returned in Ans:
1: There was no frame to retrieve.
0: A frame was successfully retrieved.