To: L4 GPS firmware update **********Attach: cdu.zip 1. Attached, please find a .zip file containing 5 items: a) CDU510.def and CDU.exe (this is a DOS-Based program that will be used to reset your receiver to factory defaults) b) 9400r.bat and 9400r.hex (this is the firmware version 1.71 for your L4 GPS receiver). c) dnld.exe (this is used to program the L4 GPS with the firmware). 2. Create a folder on your C: drive called cdu and copy the .zip file to this folder. Unzip the files into this folder. You should have all 5 files in the folder c:\cdu. 3. Connect your L4 GPS to your serial port of your PC via the ACC-CBL-B1 cable and supply power to it and turn it on. 4. Double-click on the 9400r.bat file. Follow the steps on the screen. Do not disconnect your GPS, turn it off or disconnect the cable while it is being reprogrammed! The light will turn red during this process. 5. The program will automatically finish. You can close the DOS window when it is finished. 6. With the GPS still on and connected, double-click on the CDU510.exe file. 7. The CDU program will start and will detect your firmware version. Hit when prompted to continue. 8. There are two command menus displayed: Control and I/O. 9. Do not worry if your GPS is unable to track satellites. This is because you are indoors and do not have the GPS Antenna connected. 10. After your 9400 is programmed, select "Initialization" and click on "Reset to Factory Defaults". This clears the 9400 memory. After "Reset to Factory Defaults", be sure to: -Set your local station coordinates (LAT, LON, HAE.) -Set to “Navigator” mode by using the Tab keys to get to this field and then use the SPACEBAR to toggle through the different options. (If L4 GPS is to be used as a base station, then set to "Reference" mode.) -Download a good almanac (Update the ALM.MVX at least twice a year.) from your PC (or you can wait and do this when you re-connect to your PC5L outside). -Press ENTER to save changes. (Reset laptop if COM1 does not seem to work). -After resetting to factory defaults, the 9400 goes back to the default 9600 baud rate for the Receiver Ports. Go to I/O Receiver Port Configuration to set Port 1 to 19200. Press ENTER. This will set the receiver and the CDU to 19200. (PC5L and L4 work together at 19200 baud rate.) Under Navigation Control, make sure the following settings are in place: -Set to MAX Accuracy -Minimum C/NO (signal strength) should be set to 29. -Elevation mask: 5 deg -Measurement rate: 1 Hz -Differential Navigation: Auto -HDOP Limit: 10 -VDOP Limit: 10 -Constraint altitude: Auto Coast -Acceleration Mode: Adaptive -Tepid Start Time: 30 min. Make sure these settings are saved and exit the CDU program. 11. Connect back into your backpack and do some testing to see if this solves the problem. Please let us know if you have any questions. Regards, CMT Support -------------------------------- Corvallis Microtechnology, Inc. 413 SW Jefferson Ave. Corvallis, OR 97333 --------------------------------