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QUESTION:
Which settings have to be made for a PROFIBUS DP link between a
Panel or PC with the ProTool/Pro-Runtime and the S7-200?
ANSWER:
If you want to connect a ProTool Runtime device to an S7-200,
please make sure that the S7-200 can be operated only as a DP
slave. The Panel or PC has to be implemented as DP
master on the PROFIBUS DP network and the S7-200 as DP
slave.
The following settings have to be made:
ProTool
- In ProTool you configure a PLC connection to the S7-200.
- Use "SIMATIC S7-200" as the protocol and open the
"Parameters…".
Fig. 1: Select PLC protocol
- To be able to set up a communication between the S7-200 as DP
slave and the PC as DP master, you must check the option "Only
Master on the Bus".
Example:
Five PCs are communicating via ProTool/Pro Runtime and
PROFIBUS DP with an S7-200. One PC is the DP master, i.e. the
option "Only Master on the Bus" is checked only for this PC. The
other PCs do not have a check mark set for the option "Only Master
on the Bus".
Now, if the master PC fails, communications on the PROFIBUS DP
network break down completely, because there is no master on the
bus. As soon as the master PC goes back online (ProTool/Pro Runtime
is started and the PLC connection is active), then the other PC
stations can again set up a connection to the S7-200.
It is thus recommended to declare all PCs to be master by checking
the option "Only Master on the Bus" for all the PCs, then
communications are not dependent on one single PC.
Fig. 2: Communications settings
In addition, you have to enter all the other settings for the
PROFIBUS DP connection. By pressing the "More…" button you can
specify the number of masters on the PROFIBUS DP.
Fig. 3: Number of masters
Note:
With a PC, the PG/PC interface has to be configured to "S7ONLINE
--> PROFIBUS".
Fig. 4: PG/PC interface
STEP 7 - Micro/WIN
With STEP 7-Micro/WIN, the interface of the S7-200 has to be
configured according to the parameters used in ProTool.
Notes:
- For a PROFIBUS DP communication with a baud rate > 187.5
Kbaud you need a DP interface on the S7-200.
- For the S7-22x without integrated DP interface you need an
EM277 module for the PROFIBUS DP communication (Baud rate >
187.5 Kbaud).
- More information on OP communications with S7-200 is available
in Entry ID: 14188898 "S7-200 and HMI components".
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german
