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S5 MEMORY CARD - Blowing Eprom

Created by: ThomasRJ at: 2/10/2012 10:33 PM (2 Replies)

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2/10/2012 10:33 PM	Rate (0)
ThomasRJ Posts: 2 Rating: (0)	Hi everybody, Could anybody point me to a document or tell me what blocks should not be transferred to memory card. I have a program that will not work after I download it to the memory card and then to the PLC. The module is 6ES5 374-2KG21 and the CPU is 928B I can compare after overall reset and the program loaded from memory card is matching the offline program but the PLC will run/start but will not function normally. If I download directly to the PLC from our PG the PLC runs like it should. (btw: I tested it with different memory modules) Thanks
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2/12/2012 10:27 AM	Rate (0)
jklm Platinum Member Joined: 12/22/2006 Last visit: 1/25/2022 Posts: 1742 Rating: (309)	Hello, When you load the program directly in the PLC, the program is running in RAM. If you put an EPROM in the CPU, depending on CPU type, the program runs from the EPROM itself (928-3UB12) or is copied in the internal RAM (928-3UB21) but as read-only. I guess that your problem comes from the fact that in Eprom mode, the data contained in the datablocks cannot be changed by the program. From the manual of the 928-3UB21: *EPROM mode* Once the memory card has been reloaded (via overall reset), the user memory (address OOOOH to 7FFFH) is write-protected for PG access and for write access by the user program. This corresponds to the behavior of a CPU 928B when an EPROM submodule is plugged. *EPROM mode* Code blocks and data blocks are copied from the memory card to the user memory by the system program. The system program also sets a write protection ID. This means that all copied blocks cannot be reloaded, edited or deleted. To edit data in data blocks, you must ensure that the data blocks are copied to the DB-RAM. You can copy or move data blocks that are programmed in the memory card to the DB-RAM using OB 254/0B 255 (for example, startup OB).
	Best regards jklm Suggestion was helpful? Feel free to rate it.
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2/13/2012 1:09 AM	Rate (0)
fritz Diamond Expert Joined: 10/7/2005 Last visit: 11/18/2024 Posts: 3027 Rating: (1057)	Hello ThomasRJ in addition to jklm's advice, check the program in the startup OB's (20, 21 and 22) and the Blocks thatare called from it for "G DB xyz" instructions. This instruction creates the DB's on PLC startup, so you would exclude these DB's from the EPROM. Should this instruction not be used, you'll need to change the program to utilise the already mentioned OB 254/255(do a search @ https://support.automation.siemens.comfor your CPU's part numberand you'll find its programming manual which has all the details on these OB's). I hope this helps
	Cheers fritz The advice and opinion given in this thread is that of the author and does not necessarily reflect the views of I S Systems Pty Limited. To find out how I S Systems can help you with your automation needs please visit www.issystems.com.au.
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