Dear JesperMP, Thank you for your reply. I find some document in Siemens support website but as you know, SIPART DR20 is very old version and they have a little doc. I'm also understand that using Profibus module is better but I had not qouted in the quotation so that I should try with SES module. Customer have more than 20 module so that we should pay a lot of money for this mistake, so that we should try. If you have more information, please tell me. Thank you very much!