Example 2: range of validity of data blocks
(Fig. 2-5)
Data block DB 10 is opened in program block PB 7 (C DB 10). During the
subsequent program execution, the data of this data block are processed.
After the call (JU PB 20) program block PB 20 is processed. Data block
DB 10, however, remains valid. The data area only changes when data block
DB 11 (C DB 11) is opened.
Data block DB 11 now remains valid until the end of program block PB 20
(BE).
After the jump back to program block PB 7, data block DB 10 is once again
valid.
PB 7
CDB11
BE
PB 20
CDB10
JU PB 20
BE
Range of validity of DB 10
Range of validity of DB 11
Fig. 2-5 Range of validity of an opened data block
Data Blocks
CPU 948 Programming Guide
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