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6.22 OB 254/255: Copy/Duplicate Data Blocks
Application
Copying
Conditions
Function
CPU 948 Programming Guide
C79000-G8576-C848-04
With the special functions OB 254/255, you copy individual data
blocks from a memory card to the user memory or duplicate individual
data blocks within the user memory.
The special function OB 254 and OB 255 work identically, with
OB 254 exclusively for DX data blocks and OB 255 for DB data
blocks.
Note
During the copying or duplication, the user interrupts are blocked.
No timed interrupts or process interrupts are accepted.
Copying data blocks from the memory card or duplicating data blocks
in the user memory and assigning a new block number.
By using the "copy" function of the two special function OBs
(OB 254 or OB 255 call), remember the following conditions:
• • The memory card must be plugged in before the OVERALL
RESET and must not be removed afterwards
• • The destination data block must not yet exist
• • The online function "compress memory" must not be active
A data block is copied from the memory card to the user memory and
retains its original block number. The start address is entered in the
address list in DB 0.
OB 254/255: Copy/Duplicate Data Blocks
6 - 65
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