s7-300 系统运行有两年了，近段时间联系在运行中突然死机，以下是PLC CPU记录的运行故障情况，请帮分析问题产生的根源，如何解决。
Diagnostic buffer of module CPU 315-2 DP

Order No./ Des cription Component Version
6ES7 315-2AG10-0AB0 Hardware 3
- - - Firmware V 2.0.8

Rack: 0
Slot: 2


Event 1 of 10: Event ID 16# 4302
Mode transition from STARTUP to RUN
Startup information:
- Time for time stamp at the last backed up power on
- Single processor operation
Current/last startup type:
- Warm restart triggered by switch setting; last power on backed up
Permissibility of certain startup types:
- Manual warm restart permitted
- Automatic warm restart permitted
Last valid operation or setting of automatic startup type at power on:
- Warm restart triggered by switch setting; last power on backed up
Previous operating mode: STARTUP (warm restart)
Requested operating mode: RUN
Incoming event
12:49:30.791 PM 06/19/2008


Event 2 of 10: Event ID 16# 1381
Request for manual warm restart
STOP due to: STOP caused by I/O management
Startup information:
- Startup without modified system configuration
- No difference between setpoint and actual configuration
- Time for time stamp at the last backed up power on
- Single processor operation
Current/last startup type:
- Warm restart triggered by switch setting; last power on backed up
Permissibility of certain startup types:
- Manual warm restart permitted
- Automatic warm restart permitted
Last valid operation or setting of automatic startup type at power on:
- Warm restart triggered by switch setting; last power on backed up
Requested OB: Startup OB (OB100)
Priority class: 27
Incoming event
12:49:30.790 PM 06/19/2008


Event 3 of 10: Event ID 16# 4301
Mode transition from STOP to STARTUP
STOP due to: STOP caused by I/O management
Startup information:
- Time for time stamp at the last backed up power on
- Single processor operation
Current/last startup type:
- Warm restart triggered by switch setting; last power on backed up
Permissibility of certain startup types:
- Manual warm restart permitted
- Automatic warm restart permitted
Last valid operation or setting of the automatic startup type at power on:
- Warm restart triggered by switch setting; last power on backed up
Previous operating mode: STOP (internal)
Requested operating mode: STARTUP (warm restart)
Incoming event
12:49:30.147 PM 06/19/2008


Event 4 of 10: Event ID 16# 4358
All modules are ready for operation
Operating mode: STOP (internal)
Incoming event
12:46:57.119 PM 06/19/2008


Event 5 of 10: Event ID 16# 4357
Module monitoring time started
Operating mode: STOP (internal)
Incoming event
12:46:46.070 PM 06/19/2008


Event 6 of 10: Event ID 16# 4548
STOP caused by I/O management
Previous operating mode: RUN
Requested operating mode: STOP (internal)
Internal error, Incoming event
12:46:45.630 PM 06/19/2008


Event 7 of 10: Event ID 16# 38C4
Distributed I/Os: station return
Address of the affected DP slave: station number: 3
DP master system ID: 1
Log. base address of the DP slave: Input address: 2046
Log. base address of the DP master: 2047
Requested OB: Rack failure OB (OB86)
Priority class: 26
External error, Outgoing event
12:29:56.220 PM 06/19/2008


Event 8 of 10: Event ID 16# 2943
I/O access error, writing
P area, double-word access, Access address: 292
Requested OB: I/O access error OB (OB122)
Priority class: 1
External error, Incoming event
12:29:56.208 PM 06/19/2008


Event 9 of 10: Event ID 16# 2942
I/O access error, reading
P area, double-word access, Access address: 292
Requested OB: I/O access error OB (OB122)
Priority class: 1
External error, Incoming event
12:29:56.207 PM 06/19/2008


Event 10 of 10: Event ID 16# 2943
I/O access error, writing
P area, double-word access, Access address: 292
Requested OB: I/O access error OB (OB122)
Priority class: 1
External error, Incoming event
12:29:56.205 PM 06/19/2008