请大家帮我诊断一下CPU停机的和原因 ，诊断如下：其中通信速率为500K，当速率提升到3M以上时大部分子站掉站情况！诊断时钟有问题（详见对中部分）
Event 1 of 120: Event ID 16# 38C4
Distributed I/Os: station return
Address of the affected DP slave: station number: 90
DP ｍａｓｔｅｒ　system ID: 1
Log. base address of the DP slave: Input address: 16358
Log. base address of the DP master: 16383
OB number: 86
Priority class: 26
External error, Outgoing event
01:54:43:223 am 05/22/08






Event 4 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 48
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:679 am 05/22/08


Event 5 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 16
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:679 am 05/22/08


Event 6 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 2
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:678 am 05/22/08


Event 7 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 48
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:673 am 05/22/08


Event 8 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 16
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:673 am 05/22/08


Event 9 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 2
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:673 am 05/22/08


Event 10 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 48
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:667 am 05/22/08


Event 11 of 120: Event ID 16# 2942
I/O access error, reading
P area, word access, Access address: 584
FC number: 1240
Module address: 16
OB number: 122
Priority class: 1
External error, Incoming event
12:40:11:667 am 05/22/08


Event 12 of 120: Event ID 16# 2942