-I2C port I see pulses. But it is bad response from the device. Have you tested I2C on ChipX

                I2C_Port.Config = new I2CDevice.Configuration(DevAddr, 100);
                I2CDevice.I2CTransaction[] I2C_Transaction;

                if (true)
                    I2C_Transaction = new I2CDevice.I2CTransaction[2];
                    I2C_Transaction[1] = I2C_Port.CreateReadTransaction(I2C_Read_Data);
                    I2C_Transaction = new I2CDevice.I2CTransaction[1];

                I2C_Transaction[0] = I2C_Port.CreateWriteTransaction(I2C_Cmd);
                ReplyLen = I2C_Port.Execute(I2C_Transaction, 50); //100ms time out

What is the firmware version you are using?

What device address are you using? NETMF requires a 7 bit address not 8…

Just a thought…

Cheers Ian

Same code works with the latest SDK 4.1

Now I2C works thanks