Allen-Bradley 1779-KFMR User Manual page 186

Chapter 12
Node management error codes are explained in Table 12.C. They are
returned in the extended error status byte that follows the TNS byte in the
reply. The status byte will contain an E0 (hex) if an error has occurred.
Table 12.C
Extended Status Error Codes
Code Meaning
Read Values
Use this command to read the values of any of the parameters described in
the previous section.
Command Format: