5
Configuration Examples
74/79 ekr CON 600 net – Process Data Exchange via Profibus
5.1.4.1 Cyclic Data Transfer
Read Access
Use the DPRD block for consistent read access to the cyclic data.
Link the hardware address with the matching variable in your data
block.
Fig.17: DPRD block for the read access to cyclic data
Meaning of the parameters
Parameter Description
LADDR Module address that was created in the device overview
RET_VAL Return value that provides an evaluable error code.
If successful, the value is 0.
In case of failure, an error code is output.
The meaning of the error code can be looked up in the help menu of the TIA portal.
RECORD
Memory area into which the data is to be written.
The memory area must be created by the customer first.
The length of the read data behind the LADDR must
match the length of RECORD. Otherwise, the RET_VAL
will return with an error code.
More information about the block can be found on the Siemens
information page, which you can access by pressing the F1 func-
tion key in the TIA Portal.