Siemens S7-1200 PROFIBUS - DP Data Exchange and Slave Address Setting

Configuration and program blocks
4.2 DP data exchange with the CPU
SIMATIC CM 1242-5
28 Operating Instructions, 01/2023, C79000-G8976-C245-06
7. Configure the DP slaves.
This affects the properties in the following parameter groups:
– General
– PROFIBUS address
– Mode > I-slave communication
Here, you specify the transfer areas for cyclic data exchange.
8. Configure the remaining modules and submodules according to your requirements.
9. Save the project.
Note
You will find more detailed information on configuring the individual parameters in the help
system of STEP
7.
Downloading project data
When you load the station, the project data of the CM is stored on the CPU.
4.2 DP data exchange with the CPU
DP data exchange with the CPU
No instructions are necessary for GP data exchange with the CPU.
4.3 New slave address with data record 0x2001
Starting a slave with a new slave address
The CM 1242-5 supports data record 0x2001 that can be written in the slave CPU using
SFB53 and the hardware identifier of the CM module. When this data record is written, the
slave is restarted with this address.
If you want to store the address retentively, save the address in a DB of the CPU and write the
DB to the CM during startup using OB100.
When the slave starts up, it initially goes onto the bus with its configured address. To avoid
disruptions, you should select a free address as the configured address. In this case, the CPU
starts up with an error because the slave does not signal a station return with its configured
address.