S7-300 Cpu 315

I have a problem with the S7-CPU 315 plcs. Last 2 weeks (saturday)we shutdown one of our production line for maintenance purpose. When we resume the operation in tuesday morning the PLC`s CPU give an alarm of "SF" I reset the CPU everything is fine. We shutdown the machine again on saturday. When we start the PLC again CPU give an alarm "SF" again, tried to do the same thing last week but upon resetting the CPU the "SF" alarm lit again. Checking the process system I found out that the program of all recipe is been erase and there is no communication from IM365 to process computer. Checking the problem on-line I found out that all program is erase, but the CPU has an EPROM how it is possible!. When I remove the EPROM module to the CPU and reset it the "SF" light won`t lit anymore, but when I put now the EPROM card again th SF fault is now occured.

My question is thus my EPROM CARD is the one that have a problem or my CPU`s?

I try to download the the program with out the EPROM, only 47% goes to the CPU and the downloading is stop. I try to download it with the memory card attached but same problem occured.

I just wait for the spare CPU to arrive and to see what is the main problem.

Is it an old 315 with MC, or the new type with MMC ?

If it is the new type with MMC, then resetting the PLC will also erase the MMC card.
The MMC card go bad so you should have spare MMC's available.

Anyway, before clearing errors or resetting the memory, investigate WHY it went into BF. Next time check the diagnostics buffer first.

JesperMP said:

Is it an old 315 with MC, or the new type with MMC ?

If it is the new type with MMC, then resetting the PLC will also erase the MMC card.
The MMC card go bad so you should have spare MMC's available.

Anyway, before clearing errors or resetting the memory, investigate WHY it went into BF. Next time check the diagnostics buffer first.

Click to expand...

It is an old CPU 315 with MC, I check the diagnostic buffer but I don`t find any problem about it. My only option is replace the CPU or the Memory Card. It`s not a "BF" fault, "SF" is the fault. I check the manual it said hardware or software is the problem.

IM fault

Maj. Toxido said:

It is an old CPU 315 with MC, I check the diagnostic buffer but I don`t find any problem about it. My only option is replace the CPU or the Memory Card. It`s not a "BF" fault, "SF" is the fault. I check the manual it said hardware or software is the problem.

Click to expand...

i think thats due im module check your im module sf fault ever come due to modules connected and you mention im is not working put every thing again and observe your im module

farrei said:

i think thats due im module check your im module sf fault ever come due to modules connected and you mention im is not working put every thing again and observe your im module

Click to expand...

I try it already, I also check the bus if there a loose connection or module not properly connected. I`m just waiting for the spare one that will be deliver today. I will give you all a feedback regarding this problem.

Thanks in advance!

Regards:

Sherwin

Is the battery OK ?
Sounds like the battery is dead AND there is probelm with the MC card.

Maybe the MC is bad or has never been programmed.
Try to write the program to the MC.

JesperMP said:

Is the battery OK ?
Sounds like the battery is dead AND there is probelm with the MC card.

Maybe the MC is bad or has never been programmed.
Try to write the program to the MC.

Click to expand...

The battery is working properly, I just replace it with a new one. The memory card as I check have a program in it. The new CPU is finally arrive. I will work on it now, I`ll give you all feedback regarding this problem.

Maj. Toxido said:

I`ll give you all feedback regarding this problem.

Click to expand...

It`s been confirmed that the CPU is the main problem.:site:


Thanks to all of you!


Regards:

Sherwin