Siemens SIMATIC FM 351 - Page 63

Machine Data and Incremental Dimensions
8-3
FM 351 Positioning Module
C79000-G7076-C351-02
Reading machine data
To read the current machine data from a channel, follow the steps outlined below:
• Set the following trigger bit in the channel DB:
– Read machine data (MDRD_EN)
• Call the FC ABS_CTRL function in the cyclic user program.
This enters the current machine data in the parameter DB on the CPU.
Excerpt from the Channel DB
Address Name Data
Type
Initial Value Description
35.0 MDWR_EN BOOL FALSE 1 = write machine data
35.1 MD_EN BOOL FALSE 1 = activate machine data
36.5 MDRD_EN BOOL FALSE 1 = read machine data
Writing and Reading Incremental Dimension Tables
Initial parameter assignment
If the channel does not yet have incremental dimension tables, follow the steps
below when making the initial parameter assignment without the configuration
software:
• Enter the new values in the parameter DB and save it.
• Download the parameter DB to the CPU.
• Set the trigger bits in the channel DB for the following jobs:
– Write incremental dimension table 1 (TRGL1WR_EN) and / or write
incremental dimension table 2 (TRGL2WR_EN)
• Call the FC ABS_CTRL function in the cyclic user program.
Modifying incremental dimension tables
To modify incremental dimension tables 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 incremental dimension table 1 (TRGL1WR_EN) and / or write
incremental dimension table 2 (TRGL2WR_EN)
• Call the FC ABS_CTRL function in the cyclic user program.