Optimized Blocks; S7-1200: Setup Of Optimized Blocks - Siemens S7-1200 Programming Manualline

2 S7-1200/1500 Innovations

2.6 Optimized blocks

2.6 Optimized blocks
S7-1200/1500 controllers have optimized data storage. In optimized blocks, all tags
are automatically sorted by their data type. The sorting ensures that data gaps
between the tags are minimized and that the tags are stored access-optimized for
the processor.
Non-optimized blocks only exist for reasons of compatibility in S7-1200/1500.
Advantages
The access is always as fast as possible, since the file storage is optimized by
the system and is independent of the declaration.
No danger of inconsistencies due to faulty, absolute accesses since the access
is generally symbolic.
Declaration changes do not lead to access errors since, for example, HMI
accesses are performed symbolically.
Individual tags can be specifically defined as "retain".
No settings in the instance data block are necessary. Everything is set in the
assigned FB (e.g. retentivity).
Memory reserves in the data block make it possible to change the actual
values without any loss (see chapter 3.2.7 Downloading without reinitialization)
2.6.1

S7-1200: Setup of optimized blocks

Figure 2-5: Optimized block of S7-1200
Standard
0
1
B
2
y
3
t
4
e
s
5
6
7
8
9
Properties
No data gaps are formed since larger tags are located at the beginning of the
block and smaller ones at the end.
Only the symbolic access exists for optimized blocks.
Programming Guideline for S7-1200/1500
V1.2, Entry ID: 81318674
Standard block
Bits
0 1 2 3 4 5 6
X1
B1
X2 X3
W1
X3
W2
Optimized block
Optimized
0 1
7
B
y
t
e
s
X1 X2
Bits
2 3 4 5 6 7
W1
W2
B1
X3 X4
10