John, Thank you for contacting National Instruments.
To answer your first question, whether it is better to wire a URL or reference into a DataSocket Read/Write depends on your application. When you are going to be writing or reading multiple times to the same connection (such as using a loop), it is more efficient to first open a DataSocket connection before the loop, pass a reference to your write/read functions within the loop, and then close the connection after the loop. Using only a DataSocket Read/Write will cause your connection to open and close each time the loop repeats. This can significantly increase the load on your processor and system resources. LabVIEW will allow you to supply a URL directly to a DataSocket Read/Write, which is useful if you are only going to be making one read or write. You can open multiple DataSocket connections simultaneously using DataSocket Open. It is recommended, however, that you close every connection once you have finished performing the necessary tasks for that connection. I believe you can perform both read and write functions to the same connection before closing it if you wire a =93ReadWrite=94 constant to the =93mode=94 connector of the DataSocket Open VI. I hope this helps! Matthew C Applications Engineer National Instruments
