Zebra Technologies R402 - Manual (Page 41)

^RI – RFID Get Tag Unique ID
The format for the ^RI instruction is: ^RIn
where
n = field number to store the unique ID
The unique ID will be read from the tag and available to
print or return to the host computer.
The example below reads the unique ID/serial number from a tag, and prints
it on a label:
^XA
^FO100,100^A0N, 60^FN0^FS
^RI0^FS
^FD ^FS
^XZ