Supported Configurations - Siemens Simatic S7 Series System Manual

DP master consistency
Consistency in the DP master CPU is not always buffer consistent. The DP master CPUs do
not handle the entire DP message as one indivisible object unless it is very small. The
DP master CPUs usually move the PROFIBUS data in smaller pieces. They can either move
the data to the I/O area or the user can control the movement with DPRD_DAT (Read
consistent data for DP devices) and DPWR_DAT (Write consistent data for DP devices)
instructions. Using the DPRD_DAT and DPWR_DAT instructions, you obtain the information
for one configuration "slot" at a time. Since we allow two configuration slots, it can take two
DPRD_DAT instructions to obtain all of the data. Consistency is only guaranteed for each
DPRD_DAT instruction.
8.5.1.5

Supported configurations

The following table lists the configurations that are supported by the S7-200 SMART
EM DP01 PROFIBUS DP module:
Table 8- 2
All EM DP01 configurations are buffer consistent.
1
We can mix and match any two of these configurations in an EM DP01 configuration. Here
are two examples:
● A configuration of 32 bytes input and output plus a configuration of 8 bytes input and
output yields a total of 40 input bytes and 40 output bytes.
● A configuration of 122 bytes input and output plus a configuration of 122 bytes input and
output yields a total of 244 input bytes and 244 output bytes.
The EM DP01 allows a maximum of 244 input bytes and 244 output bytes. If you use two
configurations for the EM DP01, all of the input data is contiguous, and all of the output data
is contiguous. Refer to "Example of V memory and I/O address area" (Page 382) for further
information.
S7-200 SMART
System Manual, 09/2015, A5E03822230-AC
EM DP01 PROFIBUS DP configuration options
Configuration Inputs to master
1
2
3
4
5
6
7
8
Outputs from master
Universal module
4 bytes
8 bytes
16 bytes
32 bytes
64 bytes
122 bytes
128 bytes
Data consistency
Buffer consistency
4 bytes
8 bytes
16 bytes
32 bytes
64 bytes
122 bytes
128 bytes
Communication
8.5 PROFIBUS
1
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