Sinamics v20 speed control via modbus and start/stop via DI

Hi Guys, 

I am new to this forum and i wanted to ask you for a little bit help. I struggle since few days with communication between PLC and V20. For this project i needed to use Codesys with Modbus but i think that doesn't mather a lot. When i follow the description about communicating V20 via Modbus with S7-1200 and use all the param's i can get all registers read. Also i can read and write STW and HSW but i cannot get him running. 

While i can thos V20 wire also with DI i would like to use Modbus only to set HSW and maybe Accel and Decel but for the rest start pulse via DI and alarm DO. I had to set P2000 to 0 because otherwise i got error F72 thats why i am thinking that using I/O is safer. 

Can anyone help me with Paramters so that i can achieve mij idea?