thanks for the valuable reply.
I am sorry, its not a lean.( ethernet card is used for the wincc communication)
I am little confuse on ur last line ,i.e. PCS7 does notr support 300.
My project is having CPU 315-2DP and i want to read / write data with PCS& system CPU416-2DP V 6.1.
u said that u should go for hardnet at PCS 7 end.what should i use at my end S7 300 side.