After programmin onboard readers for an RKP-2220 board, the readers have a yellow X in the system status tree of Alarm Monitoring.
One possible cause could be that the readers have not been assigned correctly in the Readers section of System Administration.
Ensure that the Reader Type for the reader that is connected to an onboard port of the LNL-2220 is configured correctly. It should be configured as either IDRC Onboard Reader 1 or IDRC Onboard Reader 2.
A common error is to use either Dual Interface Reader 1 or Dual Interface Reader 2. Using these reader types will result in the readers appearing offline.