Hi Vippi,

no offense, I really like the Italian language, but it would be easier for all of us to have the diagnostic buffer in english. Turn your TIA into english and export the buffer as Textfile. Share this Textfile and please do not just copy the content in the thread. It is easier to handle the diagnostic information for us.

I recommend you to update the FW of your S7-1200. V4.2 is very old. New FW V4.5 just came out. You don´t have to change anything in the project, The PLCs are running wiht a newer FW online than projected.

hope this helps,

regards.

hi Vippi,

thanks for changing to english.

you tried to start the PLC very often, rigth?

Unfortunally the buffer is only 50 entries long. All entries are from attempts of starting the PLC or switching on and off.

And starting is not possible because of there is no HW-configuration and program on it. Load the project(HW and SW) on the PLC and try again.

The best you can do now to prevent the PLC from having the same situation again is to update the FW as I suggested.

hope this helps,

regards,

hi Vippi,

thanks for changing to english.

you tried to start the PLC very often, rigth?

Unfortunally the buffer is only 50 entries long. All entries are from attempts of starting the PLC or switching on and off.

And starting is not possible because of there is no HW-configuration and program on it. Load the project(HW and SW) on the PLC and try again.

The best you can do now to prevent the PLC from having the same situation again is to update the FW as I suggested.

hope this helps,

regards,

Time for lightning arrestors to protect ground, supply / return wiring to the enclosure housing the PLC and related controls.  Anything that leaves the box needs to go through a lightning arrestor - if it is the likely entry point for lightning - as evidenced by components letting out their smoke, or wires / cables having running traces of black around the insulation, and so on.

As far as the PLC, I recommend a UPS upstream of the power supply feeding the PLC, and an isolated internal ground with a lightning arrestor between the internal isolated ground and earth so it can be bonded normally, but lightning strikes and tries to come in via ground, the plc ground gets isolated from earth.

This will help once in the event it is a ground problem.  The arrestor would require replacing after every lightning event that blows it out.

For power to the PLC:

external power-> ckt bkr -> transformer -> to UPS
      |                        |
      |        Earth GND       |
      +------------------------+
      |                        |
    =====                      |
     ---                       |
      -                        |________ to UPS

UPS-> ckt bkr -> Power Supply -> Ckt Bkr -> PLC
 |                |       |                  |
 |    Earth GND   |       |     Isol GND     |
 +----------------+       +------------------+
 |                        |
 |                       === [GND Arrestor]
 |________________________|
   

Vippi

 In one case I've been told there had been a residual current circuit breakers tripping, in another case they reported a short circuit in the supply line due to a live wrong operation.
In my other post on the subject I just asked how to prevent memeory reset in such cases...

Mr.V

Maybe in that time near was lightening? Maybe this occur your PLC in STOP mode and memory reset.

Isolated ground similar to this:

https://mall.industry.siemens.com/mall/en/it/Catalog/Product/ECINSGB14

Hopefully that's the Siemens Industry Mall for Italy.  The industry mall site is not very friendly with forcing it to cross borders.  I know there is an "international" resource available, but it hides very well from my day-to-day use.