In the manaul you can read:

system message 551:
An MPI/PPI connection to the PLC cannot be established using the specified Station address.

Remedy: Check MPI Station and wiring.

The Manual you can load here:
https://support.industry.siemens.com/cs/document/1135572/c7-633-c7-634-control-systems?dti=0&pnid=13615&lc=en-DE

sir;

I have checked the wiring of c7 633 . I have checked the wiring ,in between OP and CPU ribben cable connection also.  How i change the MPI address in OP and CPU separately . My think is cpu program is missing ,because why i am telling that , my technician have changed the backup battery with out the  v supply . There no memory card also . But i have back up program .But i can t download that via my MPI cable .

so sir please help me .

thanks .

You probably solved it. Anyway if the Programe is lost then you have to download through  RS-232.

If STOP LED is blinking MRES must be done .Classic battery replacement mistake .

If you have original STEP7 project it is better but if not -last correct Upload version is OK.

Panel config stays in FLASH memory except during restart special keyes pressed ...so panel config transfer is not neccessarry to be done..

LAPTOP + RS232 /MPI converter +RS232 cable..  or

PG Field + MPI cable ....

Select blocks +transfer +Load system config !!

Good luck  and Cheers,

Please Help I'm getting same error - When I try to use memory cards with this C7-633 unit.

 I'm getting the same error when I try to use this unit with the old type MMC  cards. 

If I  program the unit with our clients software without a memory card every thing is ok 'as long as I dont take out the battery and power down' the HMI is at address mpi 1 and PLC mpi 2. The PLC goes into run fine. 

I have two sized memory cards 65k and 256k, larger one is proven to work in a s7-318. 

If delete every thing of the memory cards using Field PG and then try to boot the unit with memory card in the slot. The PLC drops of MPI & DP networks and I can't can communicate.  I have to remove card and do a mem reset and it will come back at MPI 2 and then I can the re- down load PLC blocks that have been lost.   If I transfer the program to the card via field pg and boot with it.  It does the same error and drops of network if I do a MRES with this card in same error.  If I put the memory card in after the PLC has been programmed, I get the option to download to the memory card but this doesn't work and HMI faults again.

Whats Going on.

We are wanting to use this unit as a replacement as the one on site has touch inputs failing. But the one onsite has a MMC card so the client has asked me to get one for our replacement unit but I cant get it to work with it or a spare mmc card either. I'm thinking it may be our unit has a damages memory slot.

Is the MMC card only for if the main PLC has a problem and losses the program say its if its battery  goes flat.  Is the MMC card also for if the main unit goes faulty and gets replaced so as to get the PLC program back in without program software/cable. Isn't it better this is kept in a safe for this purpose anyway.     

Hello,

AutoGen_2229473

please reload program. and restore from simantic manager it will solve

own experience? If yes then other many possible reasons are related with this error so your recommendation can be not true and in some cases dangerous for system functionality.