Siemens SIMATIC PCS 7 CPU 410-5H

Structure of the CPU 410-5H
3.2 Monitoring functions of the CPU 410-5H
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
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3.2
Monitoring functions of the CPU 410-5H
Monitoring functions and error messages
The hardware of the CPU and operating system provide monitoring functions to ensure
proper operation and defined reactions to errors. Various errors may also trigger a reaction
in the user program.
The table below provides an overview of possible errors and their causes, and the
corresponding responses of the CPU.
Additional test and information functions are available in each CPU; they can be initiated in
STEP 7.
Type of error
Cause of error
Error LED
Access error
Module failure (SM, FM, CP)
EXTF
Time error
• The user program execution time (OB 1 and all interrupts and
error OBs) exceeds the specified maximum cycle time.
• OB request error
• Overflow of the start information buffer
• Time-of-day error interrupt
INTF
Power supply module(s)
fault (not power failure)
In the central or S7-400 expansion rack
• at least one backup battery of the power supply module is com-
pletely discharged.
• the backup battery voltage is missing.
• the 24 V supply to the power supply module has failed.
EXTF
Diagnostic interrupt An I/O module with interrupt capability reports a diagnostic interrupt
The synchronization module signals a diagnostic interrupt; see
Chapter Synchronization modules for the CPU 410-5H (Page 201)
The LED EXTF lights up with the first incoming diagnostic interrupt
and goes out with the outgoing diagnostic interrupt.
EXTF
Swapping interrupt Removal or insertion of an SM, and insertion of a wrong module
type.
Removing a synchronization module.
EXTF
Redundancy error
• Loss of redundancy on the CPUs
• Redundancy loss/ station failure of a switched DP station
• Failure of a DP master
• Disconnecting the PN cable of a system-redundant PN network
• Failure of a system-redundant device
REDF
CPU hardware fault
• A memory error was detected and eliminated
INTF
Program execution error
• Priority class is called, but the corresponding OB is not availa-
ble.
• In the case of an SFB call: Missing or faulty instance DB
• Process image update error
INTF
EXTF