我现在在现场调试一台300系列的PLC，CP341做从站MODBUS通信，通电后，CPU的SF灯报警，诊断信息如下：Diagnostic buffer of module CPU 315-2 DP

Order No./ Des cription Component Version
6ES7 315-2AG10-0AB0 Hardware 7
- - - Firmware V 2.6.9
Boot Loader Firmware expansion A 0.21.0

Rack: 0
Slot: 2


Event 1 of 100: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 6
Requested OB: I/O access error OB (OB122)
Priority class: 1
External error, Incoming event
01:38:53:221 pm 10/15/11


Event 2 of 100: Event ID 16# 2522
Area length error when reading
Instance DB, word access, Access address: 536
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:220 pm 10/15/11


Event 3 of 100: Event ID 16# 2522
Area length error when reading
Instance DB, byte access, Access address: 592
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:220 pm 10/15/11


Event 4 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 558
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:219 pm 10/15/11
。。。。。。
Event 96 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 558
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:148 pm 10/15/11

Event 97 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 568
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:148 pm 10/15/11

Event 98 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 556
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:147 pm 10/15/11

Event 99 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 550
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:146 pm 10/15/11

Event 100 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, word access, Access address: 548
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
01:38:53:146 pm 10/15/11
后来在程序中加入 FB7、FB8，还是有报警，诊断信息如下：
Diagnostic buffer of module CPU 315-2 DP
Order No./ Des cription Component Version
6ES7 841-0CC04-0YE0 Firmware V 5.3.0
Rack: 0
Slot: 2

Event 1 of 100: Event ID 16# 2522
Area length error when reading
Instance DB, word access, Access address: 494
FB number: 80
Module address: 2132
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:942 pm 10/15/11


Event 2 of 100: Event ID 16# 2522
Area length error when reading
Instance DB, bit access, Access address: 492
FB number: 80
Module address: 2124
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:942 pm 10/15/11


Event 3 of 100: Event ID 16# 2522
Area length error when reading
Instance DB, bit access, Access address: 492
FB number: 80
Module address: 2116
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:942 pm 10/15/11
。。。。。。
Event 98 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, bit access, Access address: 498
FB number: 8
Module address: 2324
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:922 pm 10/15/11


Event 99 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, bit access, Access address: 499
FB number: 8
Module address: 2320
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:922 pm 10/15/11


Event 100 of 100: Event ID 16# 2523
Area length error when writing
Instance DB, bit access, Access address: 499
FB number: 8
Module address: 2316
Requested OB: Programming error OB (OB121)
Priority class: 1
Internal error, Incoming event
05:42:59:922 pm 10/15/11
请问这些诊断信息到底是怎么回事？