Specifications
Technical Specifications Appendix A
439
Tip
If you are working with a data unit (consistent data) of three bytes or data units greater than four
bytes, you must use SFC14 to read the inputs of the DP slave and SFC15 to address the
outputs of the DP slave. For more information, see the System Software for S7-300 and S7-400
System and Standard Functions Reference Manual.
Table A-40 lists the configurations that are supported by the EM 277 PROFIBUS--DP module. The
default configuration for the EM 277 module is two words of input and two words of output.
Table A-40 EM 277 Configuration Options
Configuration Inputs to Master Outputs from Master Data Consistency
1 1word 1word
2 2 words 2 words
3 4 words 4 words
4 8 words 8 words
5 16 words 16 words
6 32 words 32 words
W
o
r
d
C
o
n
s
i
s
t
e
n
c
y
7 8 words 2 words
W
ord Consistency
8 16 words 4 words
9 32 words 8 words
10 2 words 8 words
11 4 words 16 words
12 8 words 32 words
13 2bytes 2bytes
14 8bytes 8bytes
B
y
t
e
C
o
n
s
i
s
t
e
n
c
y
15 32 bytes 32 bytes
Byte Consistency
16 64 bytes 64 bytes
17 4bytes 4bytes
18 8bytes 8bytes
B
u
f
f
e
r
C
o
n
s
i
s
t
e
n
c
y
19 12 bytes 12 bytes
Buffer Consistency
20
16 bytes 16 bytes
You c an configure the location of the input and output buffers to be anywhere in the V memory of
the S7-200 CPU. The default address for the input and output buffers is VB0. The location of the
input and output buffers is part of the parameter assignment information that the master writes to
the S7-200 CPU. You configure the master to recognize its slaves and to write the required
parameters and I/O configuration to each of its slaves.
Use the following tools to configure the DP master:
- For SIMATIC S5 masters, use COM PROFIBUS Windows software
- For SIMATIC S7 masters, use STEP 7 programming software
- For SIMATIC 505 masters, use COM PROFIBUS and either TISOFT2 or SoftShop
For detailed information about using these configuration and programming software packages,
refer to the manuals for these devices. For detailed information about the PROFIBUS network and
its components, refer to the ET 200 Distributed I/O System Manual.