Hello guys,

I'm having a problem with one FM458 module that is part of S7 414H redundant system with two AddFem modules connected with Profibus DP. So total configuration is 100% fully redundant. Two days ago I have noticed that one FM458 is in stop mode and I have just performed warm restart. It started the module and everything was fully functional. The plant was in scheduled standstill, so there was no risk at all. Next morning the fault was present again. IN the attachment you can find the diagnostic file. I need your help in determining the cause for this fault. Is it failing HW or somewhere in the field. Since all measurements are present in the system I doubt that error is caused by some faulty connection or equipment in the field.

Right now the plant is running so I'm not sure whether there is a risk for performing new Warm restart of the stopped module.

Can you please inspect the attached file and give me your opinion regarding the nature of the fault?

The whole plant is now runing on A configuration while module FM458 B is currently in STOP mode. I don't think that there is a risk for performing the new warm restart but would like to read you recommendation.

Thank you

Hello,

I have performed Warm restart and solved the problem but only for a while. Today it happened again. I would like to understand what exactly is causing this. Is it failing hardware (FM458) or AddFem module on Profibus address 1022 or maybe communication DP cable. If anyone has any advice I would highly appreciate it.

What I can conclude from the diagnostic file it seems that FM458 (which is standby) first loses its connection to AddFem module and that triggers the STOP mode on FM module. After few moments the communication is back again, but FM458 cannot restart by itself. Judging from the diagnostic file the very few events are:

Event 41 of 100:  Event ID 16# 430E
Memory reset executed
Previous operating mode: STOP (memory reset)
Requested operating mode: STOP (own initialization)
Incoming event
12:40:43:831 pm  05/16/17


Event 42 of 100:  Event ID 16# 4546
STOP caused by CPU memory management
Previous operating mode: RUN
Requested operating mode: STOP (internal)
Internal error, Incoming event
12:40:40:306 pm  05/16/17


Event 43 of 100:  Event ID 16# 6523
Memory reset request due to error accessing memory submodule
No relevance for user (Z2): 8480  (Z3): 5411

Operating mode: RUN
Internal error, Incoming event
12:40:40:306 pm  05/16/17

So it seems like FM458 is causing this problem.

Please have a look at the attached files.

Thanks in advance.

Hello guys,

just a small update regarding this problem. I have contacted Siemens support and I have received a recommendation to change MMC card. I was informed that this type of error suggest that MMC is defective.

I have ordered a new MMC card. In meantime I have tried the following. I turned off power supply unit of redundant rack that contains FM458-1DP with "defective" MMC card, took out the MMC put it into Siemens Field PG and Deleted its contents.

Then, while the MMC was still in PG's slot I have downloaded User program and system data again (Offline download with option "Delete TSave area"). I have returned the MMC back to the FM458-1DP module and turned power back ON. After few minutes the rack was fully synchronized and so far FM458-1DP works well (not going into stop, but it's probably still too early to conclude).

I have used procedure described here:

https://support.industry.siemens.com/cs/document/21829579/which-devices-can-you-use-to-read-from-write-to-or-delete-from-an-s7-300-mmc-(micro-memory-card)-outside-the-cpu-?dti=0&lc=en-WW

I have read on a few places on this forum that I can delete MMC only with SIMATIC Field PG.

Siemens service support suggested to change the MMC and not to delete it and download again.

I have also used option "Calculate Checksum and it reported no errors. I wonder now if there is any way to test and to be sure that MMC is really defective?

Anyway I guess in a few days I'll be know for sure whether deleting MMC and offline download solved the problem.

I hope these information can be useful to others.

Hello,

My plant seems to be having the same problem as you have described. If you remember the details could you answer a few questions?

1. Did you have to take your process offline to repair this issue or did the redundant function, if you have this built in prevent the need for a shutdown?

2. Has this problem repeated itself since your last post?

3. Would you be available for follow-up questions if/when some arise?

Thank You

Brian

hi dear;

Did you move the MMC "card" by another to make sure it was properly memory? This will help you determine the exact location of the event.

Dear All,  we have system with CPU-414 Redundant FM458-1DP. the FM module going to stop mode sometimes with in 2 days or 3 days. we have checked FM module diagnostic buffer 

STOP caused by CPU memory management

Event id: 16#F160:6AF4

Memory reset request due to error accessing memory