Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 68)

Status Words
Chapter 6
6-4
REMOTE FAULT bits are in the upper byte of this word. A REMOTE
FAULT bit is set ON when a command is received at a remote station but
cannot be executed by the remote station. This may mean one of the
following:
Remote station processor has detected a fault in its own operation or
has shut down.
Remote station processor has power OFF.
Remote station processor has mode select switch in PROGRAM LOAD
(or PROG) mode.
Cable between remote station adapter and processor is disconnected or
faulty.
Module switch setting prevents execution of the received command.
Error has been detected in communication zone of program at remote
station processor (PROG indicator may be ON).
A REMOTE FAULT bit indicates that the remote station communication
adapter or controller module received a message, but could not
communicate with its station processor to execute that command.
LOCAL FAULT bits are in the lower byte of this word, bits 00-07. A
LOCAL FAULT bit is set when the local station cannot confirm delivery
of the message to the remote station. This may mean one of the
following:
Automatic timeout of command completion by communication adapter
module.
Disconnection of the local or remote station interface module from the
Data Highway cable
Loss of power to the remote station communication adapter module
Unused station number addressed by the command.
Excessive noise along the Data Highway cable caused by other
equipment in the industrial environment.
At the same time it sets a REMOTE or LOCAL FAULT bit ON, the KA2
enters a 2-digit ERROR CODE into the ERROR CODE storage word.
(The ERROR CODE storage word is described in the following section.)
By monitoring these bits in the program, operators can be alerted to
hardware conditions that prevent normal transmission and execution of
commands. (Programming techniques for monitoring FAULT bits are
described in chapter 7.)