GE 90-30/20/Micro manual Contents

Contents

Elapsed Time Clock	2-34
Time-of-Day Clock	2-34
Watchdog Timer	2-35
Constant Sweep Timer	2-35
Time-Tick Contacts	2-35

Section 5: System Security	2-36
Passwords	2-36
Privilege Level Change Requests	2-37
Locking/Unlocking Subroutines	2-37
Permanently Locking a Subroutine	2-37

Section 6: Series 90-30, 90-20, and Micro I/O System	2-38
Model 30 I/O Modules	2-39
I/O Data Formats	2-41
Default Conditions for Model 30 Output Modules	2-41
Diagnostic Data	2-41
Global Data	2-42
Model 20 I/O Modules	2-42
Micro PLCs	2-43

Chapter 3	Fault Explanation and Correction	3-1
	Section 1: Fault Handling	3-2
	Alarm Processor	3-2
	Classes of Faults	3-2
	System Reaction to Faults	3-3
	Fault Tables	3-3
	Fault Action	3-4
	Fault References	3-4
	Fault Reference Definitions	3-5
	Additional Fault Effects	3-5
	PLC Fault Table Display	3-5
	I/O Fault Table Display	3-5
	Accessing Additional Fault Information	3-6
	Section 2: PLC Fault Table Explanations	3-7
	Fault Actions	3-8
	Loss of, or Missing, Option Module	3-8
	Reset of, Addition of, or Extra, Option Module	3-9
	System Configuration Mismatch	3-10
	Option Module Software Failure	3-11
	Program Block Checksum Failure	3-11
	Low Battery Signal	3-11
	Constant Sweep Time Exceeded	3-12

viii Series 90-30/20/Micro Programmable Controllers Reference Manual–September 1998 GFK-0467K