Siemens SIMATIC S5 - Page 93

S5-115F Manual Introduction to STEP 5
Input Stored Values
0000 : KH = A13C DW0 A13C
0001 : KT = 100.2 DW1 2100
0003 : KF = +21874 DW2 5572
Figure 2-8. Data Block Contents
Data blocks can also be created or erased in the control program ( 3.1.8).
Program processing with data blocks
• A data block must be called in the program with the C DB x operation (x = block No.).
• Within a block, a data block remains valid until another data block is called.
• When the program returns to the block that issued the call, the data block that was valid
before the block call is again valid.
When PB 20 is called, the valid data area is entered in a memory.
When the program returns to the calling block, this area is reopened.
Valid
DB
PB 7 PB 20
Valid
DB
DB 10
C DB 10
DB 10
JU PB 20
C DB 11
DB 10
DB 11
Figure 2-9. Validity Areas of Data Blocks
EWA 4NEB 811 6149-02 2-19