Com Port. This is the communications port the tag is using to read or write data from automation devices including PLCs, Controllers and IO. The STATION STATUS Display can be used to view the status of the comport. The %DAQ System Tag can also be used to monitor the Status of the comport using %DCOMST(tagname.COM). Comport numbers less than 1 represent Internal Tags (Accumulation, Constant, Calculation, System and Screen Tags). For IO Tags and Blocks, the COM Port is the physical comm. port configured in WebAccess Project Manager. For Network and Software Interfaces (like DDE, OPC and APU), the COM port may be a virtual number. For Serial and some API interfaces, the comport is the physical communications port (i.e. COM1, COM2, COM3, etc.).
-1 = Accumulation Tag (Internal Tag)
-2 = Calculation Tag (Internal Tag)
-3 = Constant Tag (Internal Tag)
0 = Local Screen Tag or %DAQ System Tag (Internal Tag)
1 to 255 = Physical Comport (Com1, Com2, etc) or Virtual
Port
Range:
-3 to 255
Units:
Field Type: Analog
Configuration: Com Port
Tag fields:
.COM read only
Syntax:
Tagname.COM
Blockname:Parameter.COM
Examples: SPEED.COM
TIC101:MEAS.COM