Commissioning
8.5 Commissioning PROFIBUS DP
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
8-33
PROFIBUS address
For the DP CPU, you must not set "126" as a PROFIBUS address.
See also
Consistent data (Page 7-8)
User-specific addressing of modules (Page 7-3)
8.5.4
Direct data exchange
Requirements
STEP 7 V 5.x or higher lets you configure "Direct data exchange" for PROFIBUS nodes. DP
CPUs can take part in direct data exchange as senders and receivers.
Definition
"Direct data exchange" is a special communication relationship between PROFIBUS DP
nodes.
Characteristic of direct data exchange are the PROFIBUS DP nodes "Listening" on the bus
for data a DP slave returns to its DP master. This mechanism allows "Listening stations"
(receivers) direct access to modified input data of remote DP slaves.
Address Areas
In your STEP 7 configuration of the relevant peripheral input addresses, specify which
address area of the receiving node is to receive data requested from the sending node.
The following types of DP-CPU are possible:
•
DP slave sending station
•
Receiving station, as DP slave or DP master, or as CPU not integrated in a master
system.