The List functions provide a higher level of performance for reading data than the tag based interface, The List functions also provide support for overlapped operations.
The List functions allow a group of tags to be defined and then read as a single request. They provide a simple tag based interface to data which is provided in formatted engineering data. You may create several lists and control each individually.
Tags can be added to, or deleted from lists dynamically, even if a read operation is pending on the list.