Saggy

Ayman Elotaify

hdhosseini

......

the moment of redundancy loss in buffer of the intact CPU explains the cause of failure of faulty CPU(it is not available in your case).Try again by putting the faulty in STOP mode after power cycle and read the buffer.

Best regards,
Hamid Hosseini

Totally agree.

I don't think that updating firmware will solve the case here because it happen in one CPU.

So, why the other CPU remain in Run with the old firmware.

If you could tell us exactly what happen in the system in the moments before all leds blinking? We will need a sketch for the HW config.

Another quick way will help you to reach to the reason, is to contact support. You have to tell them everything happen before all leds blinking, and they will send you an e-mail asking alot of questions. And they will give you a diagnostic tool called "S7-Dump" which you can use to get diagnostics during leds blinking. You will not being able to open its ouput file. You will send the output file to support and they will tell you the reason of all leds blinking.

Hope this helps.

Thanks for the reply,

yes i make update firmware both CPU,until now its ok before that i used to get LED blinking unevenly like for 6 month once such problem

where can i get S7 Dump tool,

Madhava

You mentioned this problem happens once in 6 months approx. This is very strange. I hope there won't be trouble anymore.

vikkipro

Dear All,

I found problem that all LEDs are blinking at STDBY S7 417 4H CPU suddenly at site.

I have checked some of the following things,

1. Power off and Unrack Stdby Cpu.

2. Removed memory card RAM 4MB and returned it back.

3. Remove interface Sync modules out and checked

But Master CPU is running healthy, all LEDs are blinking at stdby CPU side where as RUN LED and STOP LED are blinking alternately.

Even with laptop, Stdby Cpu is not communicated.

Please find the attached Diagnostics buffer.

Could anyone pls help me out form this. Its urgent.

Any update for your urgent case? We are keen to know more about your steps to solve this fault.

Khaled_Ezzat

vikkipro

Dear All,

I found problem that all LEDs are blinking at STDBY S7 417 4H CPU suddenly at site.

I have checked some of the following things,

1. Power off and Unrack Stdby Cpu.

2. Removed memory card RAM 4MB and returned it back.

3. Remove interface Sync modules out and checked

But Master CPU is running healthy, all LEDs are blinking at stdby CPU side where as RUN LED and STOP LED are blinking alternately.

Even with laptop, Stdby Cpu is not communicated.

Please find the attached Diagnostics buffer.

Could anyone pls help me out form this. Its urgent.

Hivikkipro

Any update for your urgent case? We are keen to know more about your steps to solve this fault.

Some cases this fault results from voltage fluctuations of the input source. Although the CPU is powered by S7-400 Power Supply which make a complete isolation between input source and output, but I recommend plugging an UPS to isolate S7-400 rack.

 Hello Vikkipro,

Kindly follow the link:

https://support.industry.siemens.com/tf/us/en/posts/s7-dump-errors/175493/?page=0&pageSize=10#post808829

Regards

OmKris

Hello Alll

I face same problem today, solved as the following:

Power OFF

CPU key moved from RUN to STOP 

Power ON

Now stop LED blinking alone in 0.5 Hz 

CPU key moved back to RUN while Power ON

Problem solved 🥳🥳🥳🥳

Good luck