Creating S7 data sources
The data source input mask opens, in which you can select the S7 data source as "Type" as a first step.
However, if you first assign a name to the data source and if this contains the word "s7", then "S7_Compatible"
is already preselected as the data source type. (This works with all data source types)
After this, the data source-specific settings adapt automatically to the S7 data source.
S7 Specific:
- Model
Select which S7 model you want to connect to.
>> Explanation of the S7 model types
- Connection type
Here you can decide between the connection type "TCP" and "MPI".
Whether both or only one of the connection types is available depends on the selected "model"
- Connection details
- Here you assign the connection information that is relevant for the desired S7.
- Enter the "IP address", "Rack" and "Slot".
- The default value for „Rack“ is „0“.
- The default value for „Slot“ is „0“
- Read timeout
The "Read timeout", which can also be set, always involves milliseconds. By default, this stands on 200 milliseconds.
After this time, the read attempt would be aborted if the variable could not be read within these 200 milliseconds. A to slow controller responses,
connection errors to the controller, or non-existence of the variable, may be grounds for a read abort. The "Read timeout" thus indicates, how
long the variable is searched until the read attempt is aborted.
- Read optimization
Here you can choose between different optimization methods:
- NONE
No read optimization, all requests are not written one after the other, stable but slow. Only recommended for troubleshooting.
- CROSS_AREAS
Read requests are merged across areas. Advantage: Fragmented areas (e.g., data across multiple data blocks) can be read and written simultaneously.
- COMBINE_AREAS
Read requests from identical areas are combined. Advantage: Fast and high-performance access to data of the same areas (for example, data in the same data block).
- AUTO
Selects the best optimization method. Only the minimum required PLC read access are carried out.
After entering the information relevant for the connection, click on "Add".
And after editing an already created data source, click on "Save".
The S7 data source is created and subsequently displayed in the data source overview.
Created data sources can be edited or deleted. You do this via the corresponding buttons. You also have the option of viewing all internal data sources.
This works by activating the checkbox "Show internal data sources".
Below you can create variables for the S7 data source.
You can find out how to add variables for the S7 data source in the “Adding S7 variables” chapter: