Siemens S5-100U - Block Types

S5-100U Introduction to STEP 5
7.3 Block Types
The following table lists the most important characteristics of the individual block types:
Table 7-2. Comparison of Block Types
1
The operating system calls up particular OBs automatically (see section 7.3.1 and 9.3).
2 Function blocks are already integrated into the operating system (see section 9.2).
3 Data blocks DB0 and DB1 are reserved.
OB
1
PB SB FB
2
DB
3
64
OB0 to OB63
Number
CPU 100
64
PB0 to PB63
62
DB2 to DB63
64
FB0 to FB63
64
OB0 to OB63
Number
CPU 102
64
PB0 to PB63
62
DB2 to DB63
64
FB0 to FB63
Basic
operations
Operations
set
(contents)
Basic
operations
Basic
operations
STL, CSF,
LAD
Representa-
tion methods
STL, CSF,
LAD
STL, CSF,
LAD
5 wordsBlock header
length
5 words 5 words
Bit patterns,
numbers,
texts
5 words
Basic,
supple-
mentary,
system
operations
STL
5 words
8 Kbytes 8 Kbytes
Length (max.)
CPU 103
8 Kbytes 8 Kbytes 8 Kbytes
4 Kbytes
Length (max.)
CPU 102
4 Kbytes 256 data words4 Kbytes
4 Kbytes
Length (max.)
CPU 100
4 Kbytes 256 data words4 Kbytes
256
SB0 to SB255
256
OB0 to OB255
Number
CPU 103
256
PB0 to PB255
254
DB2 to DB255
256
2
FB0 to FB255
EWA 4NEB 812 6120-02 7-7