GFK-0467K Chapter 3 Fault Explanation and Correction 3-13
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No User Program Present The Fault Group No User Program Present occurs when the PLC CPU is instructed to transition
from STOP to RUN mode or a store to the PLC and no user program exists in the PLC. The PLC
CPU detects the absence of a user program on power-up. The fault action for this group is
Informational.
Correction: Download an application program before attempting to go to RUN mode.
Corrupted User Program on Power-Up The Fault Group Corrupted User Program on Power-Up occurs when the PLC CPU detects
corrupted user RAM. The PLC CPU will remain in STOP mode until a valid user program and
configuration file are downloaded. The fault action for this group is Fatal.
Error Code: 1
Name: Corrupted User RAM on Power-Up
Description: The PLC operating software (operating software) generates this error when it
detects corrupted user RAM on power-up.
Correction: (1) Reload the configuration file, user program, and references (if any).
(2) Replace the battery on the PLC CPU.
(3) Replace the expansion memory board on the PLC CPU.
(4) Replace the PLC CPU.
Error Code: 2
Name: Illegal Boolean OpCode Detected
Description: The PLC operating software (operating software) generates this error when it
detects a bad instruction in the user program.
Correction: (1) Restore the user program and references (if any).
(2) Replace the expansion memory board on the PLC CPU.
(3) Replace the PLC CPU.
Password Access Failure The Fault Group Password Access Failure occurs when the PLC CPU receives a request to change
to a new privilege level and the password included with the request is not valid for that level. The
fault action for this group is Informational.
Correction: Retry the request with the correct password.