Technical data

Active components
4.8 Active components for the link between PROFIBUS (DP slave) and AS-Interface
PROFIBUS Network Manual
108 System Manual, Edition 04/2009, C79000-G8976-C124-03
S7-400
e.g. with
CP 443-5 Extended
DP/AS-Interface
Link 20E
PC/IPC
with CP
5621
S7-300 with DP master
Compact
branch
3RA6
Power
supply
unit
Digital/analog slavesSafe
slave with
EMER STOP
Laser
scanners
Safety
monitor
PROFIBUS
AS-Interface
LOGO!
Figure 4-31 Example of a configuration with the DP/AS-Interface Link 20E
Function
DP/AS-Interface Link 20E allows a DP master to access all the slaves in an AS-Interface
segment. In line with the extended specification (V3.0), up to a maximum of 62 slaves each
with four digital inputs and four digital outputs as well as analog slaves can now be
connected.
The DP/AS-Interface Link 20E is normally assigned 32 bytes of input data and 32 bytes of
output data on the DP master on which the I/O data for the connected AS-Interface slaves is
stored. The size of the input/output buffer can be compressed so that only the memory
actually required on the DP master is used.
PROFIBUS DP masters can also trigger AS-Interface master calls using the acyclic
PROFIBUS services (for example: write parameters, change addresses, read diagnostic
values).
Configuration
DP/AS-Interface Link 20E can be configured on PROFIBUS with STEP 7.
The GSD file is also supplied with the manual, which means that configuration can even be
carried out for versions in which DP/AS-Interface Link 20E is not yet normally available.
The AS-Interface segment can be configured with STEP 7 or simply by adopting the actual
configuration. Commissioning is also possible without PROFIBUS.
If STEP 7 is used for the configuration, the AS-Interface configuration can be uploaded to
STEP 7 as of version V5.2.