ABB AC500-S Safety User Manual page 253

4.6.4.12 SF_FLASH_WRITE
Writing of user data to the Flash memory
The function block writes a data set to a data segment in the Flash memory. For that purpose, two data seg-
ments are available in the SM560-S controller. The delete operation (function block SF_FLASH_DEL) always
deletes a data segment as a whole. One data segment consists of 1724 blocks (0 ... 1723). Each block com-
prises 38 bytes. The maximum number of writing cycles to the Flash memory is limited. Deleting data in the
Flash memory is also considered to be a "writing" cycle.
After a delete operation, data can be written only once to each of these 1724 data segment blocks. If a block
containing data is to be overwritten with new data, the entire data segment has to be deleted first. In doing
so, all data in this segment will be lost.
NB blocks are read starting at address SM and stored in segment SEG starting at block BNR.
32 binary data or 16 word data or 8 double word data are read per block.
One block contains 38 bytes:
n 32 bytes of data
n 4 bytes for CRC checksum
n 1 byte as "written" identifier
n 1 byte for alignment
(See figure at the end of the SF_FLASH_READ function block description. )
Once the write operation for a data set has been started (by a FALSE/TRUE edge at input EN), the data
contained in the data set must not be changed anymore until the write operation completes (DONE = TRUE).
Storing the data set in the Flash can take several PLC cycles.
With a FALSE/TRUE edge at input EN, the data set is written once. Input EN is not evaluated again until the
storage procedure is finished (DONE = TRUE).
After the write operation is finished, the function block outputs DONE, ERR and ERNO are updated. Data
storage was successful if DONE = TRUE and ERR = FALSE. If DONE = TRUE and ERR = TRUE, an error
occured. The error type is indicated at output ERNO.
A new FALSE/TRUE edge at input EN starts a new write operation. Input BNR must point to the next free
block for the next write operation since no new data can be written to blocks that already contain data
without a preceding deletion of the data segment.
30.03.2017
Configuration and programming
AC500-S Libraries > SafetyExt_AC500_V22.lib
AC500-S 253