Siemens B4 Benutzerhandbuch
Automation– and Drive Technology- SCE
2.
NOTES FOR DATA BLOCKS
Data Blocks (DBs) can be used by your program to save data in the CPU. Your hard disk contains up
to 8 KBytes ( 8192 Bytes ) space.
There are two types of data blocks. Global DBs, where all OBs, FBs and FCs read all saved data or
can even write in the DB and local instance DBs, which are assigned a particular FB.
In the DBs, different data types (e.g. BOOL or WORD ) can be saved in arbitrary order.
This structuring of a DB follows through input in a table with the tool
LAD, STL,FBD - S7 Block Programming .
In the program structure from STEP 7, data blocks are found as follows:
to 8 KBytes ( 8192 Bytes ) space.
There are two types of data blocks. Global DBs, where all OBs, FBs and FCs read all saved data or
can even write in the DB and local instance DBs, which are assigned a particular FB.
In the DBs, different data types (e.g. BOOL or WORD ) can be saved in arbitrary order.
This structuring of a DB follows through input in a table with the tool
LAD, STL,FBD - S7 Block Programming .
In the program structure from STEP 7, data blocks are found as follows:
OB = Organization Block
Instance DB
Global DB
L DB11.DBW0
OB 1
DB 11
DB 10
FB 1
Call FB1, DB10
UC FC2
FB = Function Block
FC = Function
DB = Data Block
FC = Function
DB = Data Block
Local data only
FB1
FB1
For all
FBs
FCs
OBs
FBs
FCs
OBs
BE
T I A Training document
Page 6 of 18 Module B4
Last revision: 02/2002 Data block
Forward Notes Generating data blocks