Rockwell Automation GMLC Reference Manual - Manual (Page 588)

Publication GMLC-5.2 - November 1999
551
In the Tag Explorer select General System Variables, then select
DH-485_fault_code in the Tag Window.
When DH485_fault_code > 0, DH485_general_fault = 1 (DH-485 fault).
When DH485_fault_code = 0, the remote device received and accepted
(acknowledged) the message sent by the motion controller.
When DH485_fault_code
≥
5, the remote device received the message
from the motion controller but may not have executed the requested
action. In this case, DH485_fault_code is the value of the status (STS)
byte of the response from the remote device as received by the motion
controller. Consult the documentation for the remote device to determine
the meaning of DH-485 status codes greater than or equal to 5.
Important: Although DH485_fault_code is a decimal value in GML
Commander, the STS byte is most often documented
elsewhere as a hexadecimal value.
The four lowest-numbered DH-485 faults are described below.
Command Failed
A command failed fault (DH485_fault_code = 4) indicates that the device
to which the message was sent did not accept (negative acknowledged)
the message. Verify that the remote DH-485 device is configured to
accept DH-485 messages from the motion controller.
Fault
Code
Description
5 Remote Device Response STS Byte
4 Command Failed
3 Response Timeout
2 Transaction ID Mismatch
1 Bad Command
0 No DH-485 Fault