8. TROUBLESHOOTING
8
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1
MELSEC-A
8. TROUBLESHOOTING
This section describes errors which may occur when using a DN91 master unit and the
troubleshooting procedures.
This section is divided into the following sub-sections.
Section 8.1 Troubleshooting Tables
Determine the appropriate remedy from the symptom of the problem.
Section 8.2 Troubleshooting using LED Indications
Determine the appropriate remedy from the LED indicator status.
Section 8.3
Troubleshooting using Error Codes
Determine the appropriate remedy from the error codes.
The timing to check the error codes and the reference buffer memory
are
shown below.
Timing to Check Error Codes
Error Codes to Check
Remedy
When the error set signal (Xn3)
turns ON
Communication error code
(01B1
H
, upper byte)
Take remedial actions in accordance with Section
8.3.1 “Communication error codes”..
When the message communication
complete signal (Xn2) turns ON.
Error code (0121
H
) after conducting
message communication.
See 8.3.2 Execution Error Codes for Message
Communication.