Hi,\r\nI am a new gps user and using u-blox Neo-4S GPS receiver. I want to use DGPS and as i know it supports DGPS. For that purpose is use an evaluation software created by u-blox company called u-center. There are some protocols supported by the receiver and one of them is ubx protocol. By sending configuration messages on that protocol the UART port can be configured. As i know DGPS data is sent to the receivers on RTCM protocol. I want my port to handle messages come on that protocol in order to get DGPS data, am i wrong here? Secondly, when i try to send config. messages on ubx protocol to the receiver i can not succee. My message is interpereted as an unknown message or the reply is interpereted as that. In the message view window of u-center interface there are some options for messages to be sent. I choose ubx-config-prt respectively to send he message i mentioned to the recever. What am i missing, can anybody help me?\r\nThanks.