GE 90-30/20/Micro manual Fault Tables, Attribute Description, Fault Summary

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Note

For information specific to Micro PLC fault handling, refer to chapter 7 of the

Series 90 Micro PLC User’s Manual (GFK-1065).

System Reaction to Faults

Typically, hardware failures require that either the system be shut down or the failure is tolerated. I/O failures may be tolerated by the PLC system, but they may be intolerable by the application or the process being controlled. Operational failures are normally tolerated. Series 90-30, 90-20, and Micro PLC faults have two attributes:

Attribute

Description

Fault Table Affected	I/O Fault Table
	PLC Fault Table
Fault Action	Fatal
	Diagnostic
	Informational

Fault Tables

Two fault tables are maintained in the PLC for logging faults, the I/O fault table for logging faults related to the I/O system and the PLC fault table for logging all other faults. The following table lists the fault groups, their fault actions, the fault tables affected, and the “name” for system discrete %S points that are affected.

Table 3-1. Fault Summary

		Fault
Fault Group	Fault Action	Table	Special Discrete Fault References
Loss of or Missing I/O Module	Diagnostic	I/O	io_flt	any_flt	io_pres	los_iom
Loss of or Missing Option Module	Diagnostic	PLC	sy_flt	any_flt	sy_pres	los_sio
System Configuration Mismatch	Fatal	PLC	sy_flt	any_flt	sy_pres	cfg_mm
PLC CPU Hardware Failure	Fatal	PLC	sy_flt	any_flt	sy_pres	hrd_cpu
Program Checksum Failure	Fatal	PLC	sy_flt	any_flt	sy_pres	pb_sum
Low Battery	Diagnostic	PLC	sy_flt	any_flt	sy_pres	low_bat
PLC Fault Table Full	Diagnostic	—	sy_full
I/O Fault Table Full	Diagnostic	—	io_full
Application Fault	Diagnostic	PLC	sy_flt	any_flt	sy_pres	apl_flt
No User Program	Informational	PLC	sy_flt	any_flt	sy_pres	no_prog
Corrupted User RAM	Fatal	PLC	sy_flt	any_flt	sy_pres	bad_ram
Password Access Failure	Diagnostic	PLC	sy_flt	any_flt	sy_pres	bad_pwd
PLC Software Failure	Fatal	PLC	sy_flt	any_flt	sy_pres	sft_cpu
PLC Store Failure	Fatal	PLC	sy_flt	any_flt	sy_pres	stor_er
Constant Sweep Time Exceeded	Diagnostic	PLC	sy_flt	any_flt	sy_pres	ov_swp
Unknown PLC Fault	Fatal	PLC	sy_flt	any_flt	sy_pres
Unknown I/O Fault	Fatal	I/O	io_flt	any_flt	io_pres

GFK-0467K Chapter 3 Fault Explanation and Correction 3-3