Transferring The Control Data Record In The User Program Of The Cpu - Siemens SIMATIC ET 200AL System Manual

Configuration control (option handling)

7.4 Transferring the control data record in the user program of the CPU

7.4 Transferring the control data record in the user program of the CPU
Required steps
Transfer the created control data record 196 to the interface module using the WRREC
(Write data record) instruction.
Parameters of the WRREC instruction
Below, you will find explanations of individual parameters of the WRREC instruction which
you must supply with specific values in the configuration control context. You can find
additional information on the WRREC instruction in the STEP 7 online help.
ID
INDEX
RECORD
Selection of the station option in the user program
In order for the CPU to know which station option you want to operate, you must set up a
possibility to select between the various control data records in the user program. You can
implement the selection, for example, via an Int tag that references an array element. Note
that the tag for selecting the control data record must be located in the retentive memory
area. If the tag is not retentive, it will be initialized during startup of the CPU and will thus be
unavailable for selection of the station option.
Special requirements relating to the transfer of the control data record to the interface module
● If you have enabled configuration control, the ET 200AL station is not ready for operation
without a control data record. As long as no valid control data record has been
transferred, the I/O modules are considered as failed by the CPU and exhibit substitute
value behavior. The interface module continues to exchange data.
● The control data record is stored retentively in the interface module. Note:
– If the configuration is unchanged, you do not have to rewrite the control data
– If you write a control data record with modified configuration, this will result in a station
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HW identifier of the interface module.
If you have selected the interface module in the network view or device view, the HW
identifier is available in the System constants tab of the Inspector window. Use the
value of the system constant "<Name_of_interface_module> Head".
Data record number: 196 (decimal)
Control data record to be transferred.
You can find the structure of the control data record in section Control data record for
the ET 200AL distributed I/O system (Page 55).
record 196 during restart.
failure in the distributed I/O system. The original data record 196 is deleted and the
new data record 196 is saved retentively. The station will then restart with the modified
configuration.
Distributed I/O system
System Manual, 08/2019, A5E31861578-AG