Device's Constant Scan Tag Count.  Describes the number of  Tags on a Device using the Constant Scan-type.   This is useful for optimizing communication load and communication diagnostics. Constant Type Scanning means the Tag is always scanned, even if it is not  on a graphic display viewed by a user.  Data Logging and ODBC logging require Constant Scanning. See also 4.2.6 Scan Type, 3.3 Communication Ports and 3.4 Device Configuration.