Siemens SIMATIC FM 353, Manual

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Programming the Technological Functions
6-30
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
6.4.2 The POS_INIT (FC 0) block − Initialization
Block description
See Section 6.3.2.
6.4.3 The POS_CTRL (FC 1) block − Data exchange
Function
The POS_CTRL block is the basic block for controlling the FM 353.
With the POS_CTRL block, you can:
S process read and write requests
S control the operating modes (control and checkback signals)
The POS_CTRL block performs the following actions:
1. Synchronization with the module (only then is the exchange of signals/data pos-
sible).
2. Reading of the checkback signals. The values/signals read by the POS_CTRL
block are stored in the user data block AW-DB.
3. Transfer of the control signals from user data block AW-DB to the FM 353.
4. Carrying out of Write requests from user data block AW-DB, which includes the
transfer of associated data from AW-DB and setting of the job status for the
Write. Before the function is activated, all data required for the execution of the
intended functions must be entered in AW-DB.
5. Carrying out of Read requests from user data block AW-DB, which includes
transfer of the associated data to AW-DB and setting of the Read job status.
6. Automatic transfer of all single functions from user data block AW-DB to the
FM 353 when one or more than one setting has been changed and setting of
the Write job status (Set or Reset).
7. Automatic transfer of all single commands from user data block AW-DB to the
FM 353 and setting of the Write job status. The single commands are reset fol-
lowing the transfer.
8. Automatic reading of the error number when an operator input error, traversing
error or data error has occurred. The error number is entered in user data block
AW-DB (DBB90 to DBB97) and the Read job status set.