Nmea Output Configuration In Pc-cdu 42ec

NMEA Output Configuration in PCCDU PCCDU is GPS-receiver configuration software made by Topcon that is used to configure Topcon GPS receiver setting such as the positioning method, base and rover configuration and ports. The special part about PCCDU is it can generate NMEA output that can be used for other software that may need NMEA input sentence for collecting data such as HydroPro. After configuring the receivers (base and rover) in RTK-Fixed mode, a special command need to be inserted for generating the NMEA sentence in the manual mode that will be explained further in this topic. Connecting to PCCDU Select the port where the GPS is connected to in the Connection Parameters and specify the baud rate and connection mode used. In this project, the GPS is connected to COM4, direct connection mode and baud rate of 9600 is used. If the receivers are not yet configured to RTK-Fixed positioning method, it is necessary to select the ive mode in the Program settings selection. Manual mode only selection can be directly chosen if the receivers have been configured in RTK-Fixed positioning mode. Figure below shows the Connection Parameters window.

It will take couple of seconds for the COM to get connected with PCCDU. After the GPS is connected to PCCDU, it will start getting the position for the area. The positioning method for the receivers used in this project is in RTK-Fixed method. The rover receiver will display the RTK-Fixed positioning method as soon as the base receiver has begun transmitting corrections. If base station has not yet begin transmitting corrections, the rover receiver will be in standalone positioning mode because it does not receiving corrections from the base receiver. Further explanations about RTK technique are discussed in the Literature Review chapter. Figure below shows the data logged into PCCDU from the rover receiver in RTKFixed mode.

Manual Mode Configuration After the receiver had successfully connected to PCCDU, go to the Manual Mode option under the File tab in the PCCDU window interface. In the Manual Mode window, empty script window will appear if no previous command is set into it. To begin sending NMEA sentence output, the NMEA output command need to be typed in the command box at the top of the window. The NMEA output command is: %%em,,/msg/nmea/GGA:1

This is the special command that can send NMEA output from PCCDU to HydroPro. The logging time for the output can be controlled by changing the GGA:1 to GGA:5 or GGA:10 depend on the requirement where the number specify time in second. For example if GGA:1 is used, so the output will transmitted every one second time interval. After finished typing the command, send the command by clicking the Send Command button to begin sending NMEA output. NMEA sentence will appear in the window in a interval of the time set at the GGA:1. Before testing the NMEA input in HydroPro, need to be ed that the command should not be stopped and just click the Disconnect button so that the COM port can be used in HydroPro to receive the NMEA output. Exit PCCDU as soon as it has been disconnected. Figure below shows the NMEA sentence after command has been type in the command box. There are many other commands that can be inserted in the manual mode.