Siemens S5-135U/155U - Manual (Page 220)

5-80
System Manual
C79000-G8576-C199-06
5.8 374 Flash EPROM Cards
This section provides a summary
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of the use of the 374 flash EPROM cards (known as the 374 memory
cards in the following) in the CPU 948, CPU 928B-3UB21 and
CPU 928-3UA21
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and of the technical specifications.
5.8.1 Technical Description
The 374 memory card serves as a storage medium for user programs and user
data. It contains electrically erasable flash EPROMs.
The 374 memory card is available in the following capacities:
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256 Kbytes
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512 Kbytes
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1024 Kbytes
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2048 Kbytes
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4096 Kbytes
The order numbers for the SIMATIC S5 memory cards can be found in the
ordering information.
5.8.2 Notes on Operation
You can program and erase the 374 memory card off-line on the SIMATIC S5
programmers. The link to the PG is provided by a special connector or
programming adapter, into which the memory card is inserted. A description
of EPROM programming can be found in the STEP 5 manual.
Memory cards can be inserted and removed at any time, even whilst the CPU
is running, as long as they are not being accessed (see the CPU 948
Programming Guide).
The contents of the memory cards are only copied automatically into the
internal RAM of the CPU upon overall reset of the CPU.
Memory cards are electrically erasable.
Ordering
Information
Programming a
Memory Card
Inserting and
Removing a
Memory Card
Loading Data
Erasing a Memory
Card
CPUs, Memory Cards, Memory Submodules, Interface Submodules