Writing And Reading Machine Data And Incremental Dimension Tables - Siemens SIMATIC FM 351 Manual

Machine Data and Incremental Dimensions
8.1 Writing and Reading Machine Data and Incremental Dimension
Tables
This chapter describes how to modify and read out parameters during operation
using your application.
All the parameters are stored in the parameter DB.
The machine data are in the parameter DB at addresses 4.0 to 116.0.
Incremental dimension tables are located in the parameter DB from addresses
120.0 to 516.0.
You must enter the number of the parameter DB in the appropriate channel DB.
You can enter the parameters either with the DB editor or more conveniently in the
dialogs "Drive", "Axis", "Encoder" and "Incremental Dimensions" and write them to
the parameter DB using the "Export" function.
You can import the parameters from an existing parameter DB into the dialogs with
the "Import" function.
Writing, Activating and Reading Machine Data
With the machine data, you adapt the FM 351 to the axis and the encoder.
Initial parameter assignment
If the channel does not yet have machine data, follow the steps outlined below
when assigning parameters for the first time without using the parameter dialogs:
Enter the new values in the parameter DB and save it.
Download the parameter DB to the CPU.
Set the following trigger bit in the channel DB for the job:
– Write machine data (MDWR_EN).
Call the FC ABS_CTRL function in the cyclic user program.
Modifying machine data
To modify machine data using your application, follow the steps outlined below:
Enter the new values in the parameter DB.
Set the trigger bits in the channel DB for the following jobs:
– Write machine data (MDWR_EN)
– Activate machine data (MD_EN)
Call the FC ABS_CTRL function in the cyclic user program.
If you set the trigger bits for these jobs all at once, FC ABS_CTRL makes sure that
the jobs are processed in the correct order.
Otherwise, always modify the machine data in the following order:
write machine data
activate machine data
8-2
FM 351 Positioning Module
C79000-G7076-C351-02