Hello , 

         I have a PC software written in visual studio c++ language that calculates the angular rotation ,  & angular velocity of a motor shaft based on the application (for example 20 degree rotation from zero position with velocity 1 rad/sec )  .I have already chosen the motors to be Ac servo motors .

      The motors come with drivers & control unit cu-320 ( found it in cataloge PM21 for siemens servo motors) which accepts communications ONLY in profibus or profinet (i have a general idea about them but no idea about the protocol from inside , data packet and etc. )

The problem is : How can i send my data values ( rotation & velocity in rpm ) to the control unit which will send them to the driver ?

Please help . Thank you in advance

Hello Mh_Ismail;

To connect a PC to Profibus-DP, you need a special inteface bopard with a Profibus ASIC and functions that will allow it to participate in the network either as master or as slave.

Siemens and other companies make these boards, but generally the application layer will not let you implement a C/C++ program; they are designed to accomodate the PLC programs generated by the vendors. For example a Siemens CP 5613 a2 is designed to accept either Step 7 or WinCC drivers, for PLC and HMI controls.

PG/PC Profbus - CP 5613 A2/CP 5614 A2

You could look into special Profibus boards that accept high-level programming blocks such as this offering:

http://www.sorcus.com/english/pdf/flypcbus.pdf

Hope this helps,

Daniel Chartier

I don't want to implement my code to the control unit , for example i have the 2 values 20 degree & 2 rpm , i want to send these values not the entire code( by turning them to binary numbers for example and sends them to some parameters ...but i know it isn't that simple).

 i can save these 2 values into txt file , i can send them via UART or RS 232 directly from c++ application... but there should be something in between the pc & control unit which recieves UART or Rs232 (or 485) from pc and sends the 2 values to the control unit via profibus.

for example i wanted to use microcontroller which will recieve these values via USB (pic32 microchip have usb interface) and later sends them to control unit ....BUT for sorry microcontroller cannot communicate with profibus ...so what should i do?