[?]: S5 eprom Format

SIMATIC S7-200/300/400, Step7, PCS7, CFC, SFC, PDM, PLCSIM,
SCL, Graph, SPS-VISU S5/S7, IBHsoftec, LOGO ...
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Posts: 2
Joined: Tue Nov 18, 2008 1:41 pm
Location: America

[?]: S5 eprom Format

Post by juanjo » Wed Nov 19, 2008 10:49 am

Hello Folks!.

I are seeing if anybody know the Format if a S5 program in the eprom module, i can discover the Sync word Starting with 70 70 and the following number tell the block type
(C1 fot Db´s, C4 for Pb´s, C8 fo Fb´s, D0 for OB´s....)
the follwing number tell the block number....
well in the header i need to dechiper the following six numbers.
i see the end of block end with "65 00" .

i are interest in how the S5 make the directory of the eprom, and how the block must me allocated inside the eprom, also y can discover how mark the end of the program in the eprom.

any help is wellcome



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Location: Europe

S5 Blcok Header

Post by mogz » Thu Nov 20, 2008 6:38 pm

All S5 blocks(PB,SB,FB,FX,DB etc) have a header that is not displayed by the Step 5 software.
The header is made up of 5 words.
Word 1 = Syncronization pattern (7070)
Word 2 = Block Type and Block number
Word 3 = PG Identifiers and first part of Library number
Word 4 = Contains 2 bytes of the library number
Word 5 = Length of the block in words.

Word 2 Low byte = Block Number
Word 2 High Byte = Block type.
Word 2 Bit 8 On = Block type DB
Word 2 Bit 9 on = Block type SB
Word 2 Bit 8 & 10 on = PB
Word 2 Bit 11 on = FB
Word 2 bit 10 & 11 on = DBX
Word 2 bit 12 on = OB
Word 2 bit 13 on = Test Block
Word 2 bit 14 & 15 off = Block invalid
Word 2 bit 14 On = Block in Ram Valid
Word 2 bit 15 On = Block is intended for eprom
Word 2 Bit 14 & 15 on = Block in eprom is valid.

There must be sililar information for S7 but never seen it?

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Joined: Tue Nov 18, 2008 1:41 pm
Location: America

Post by juanjo » Fri Nov 21, 2008 2:06 pm

Hello Mogz.!!

thanks by te info, now i clear the sync pattern!


So i can undestrand this , i try to asembly a block and test.
but i still get a dude, the check sum is calculated ovbius at
booting time, but is compared with a chek sum stored in the module at programing time?, or at boot time calculate this checksum, stored and later in ach startup is compared to see if the eprom image is valid?

Thanks Again.

Juanjo :D

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