profibus communication: Siemens 314c 2dp and Micromaster MM4

[italo2008]

Hi
I have some doubts about profibus communication between a plc siemens (314C 2DP) and the inverter SIEMENS MICROMASTER 420

1)I have read that there are 5 types of PPO that depend on the number of words dedicated to process data and parameters. But who establish the structure of the command word (example: wich parameter corresponds to the first bit,wich parameter corresponds to the second bit and so on)? Can I define the structure or is it fixed?
2)How can I tell the inverter that I want the motor to rotate clockwise or counterclockwise if a condition is true or false?

thanks...

 

[JRW]

Look under the DOWNLOAD section > Siemens. There are drive fb's there

 

[mel_w]

the attached document is the structure of the control word
bit 11 reverses the motor direction
regards
Mel

 

[SiemensPLC]

Did this give you the information you needed to get your application working?

 

[FARIAM]

If you only need to start/stop the drive, change the setpoint and receive the actual value, then you only need PPO3. The control word and status word are fixed, and they are described in the MM4 manual. Mel_W has attached a picture of it.
In this case you only need to transfer values to the control word (or a specific bit), and transfer the setpoint (INT range from 0 to 16480)to the according configured HW addresses. For example, the basic value to STOP would be W#16#047E and to START would be W#16#047F.

If you also need to read the current, torque, etc or change a parameter through the PLC, then you would need PPO1, but that is a little more complicated because you have to send and receive commands using SFC14 and SFC15.

Regards