Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 201)

Appendix
C
CĆ1
General Asynchronous Link Error Codes
(STS, EXT STS)
Asynchronous link (RS-232-C) error codes are passed in the link message
packets. You can find these codes in the:
Status (STS) Byte of the Message Packet
Extended Status (EXT STS) Byte of the Packet (for Some Commands)
The STS is divided into two nibbles (4 bits):
The Local Error Nibble
The Remote Error Nibble
3 6 5 4 7 2 1 0
Remote Error Nibble
Bit
Local Error Nibble
Local STS Error Codes
The local STS error code nibble contains errors found by local
asynchronous link layer. The following table contains error codes (in hex)
that you may find in the local error code nibble of the STS byte:
This
Code
Means
0
1
2
3
4
Success Ċ No Error
Destination Station Out of Buffer Space
Remote Station Specified Does not Acknowledge (ACK) the Command Message
Duplicate Token Holder Detected
Local Port Is Disconnected
Local STS Codes 5 through F (hex) are not used.
Where to Find Asynchronous
Link Error Codes
The STS Byte