You can log and plot about 15 seconds worth of data using the program downloaded from here:
http://members.cox.net/seanwitte. There are directions in the readme file. You will need the C header and source files, pc_interface.h and pc_interface.c, that are in the zip file.
Extract all of the files onto your PC and run setup.exe to install it. You can uninstall the software using the windows add/remove programs function.
Add the C source files to your project and include pc_interface.h in user_routines.c. During the initialization make a call to InitializePCInterface() to set up the data packets. Each time through the program loop make a call to SendReceivePCData(). You can put it right before putdata().
It will let you send back 8 bytes (aliases fb_pwm01 through fb_pwm08), 6 signed integers (sensor1 through sensor6) and 16 bits (fb_sw01 through fb_sw08 and fb_sw10 through fb_sw18). You can log and plot up to ten of the values at once. Once you have a plot you can save the data as a .csv file or a bitmap. The bitmaps are huge, but its the only option I had easily available at the time. The x-axis on the plots is the time in milliseconds.
If you're using a positioning system you can display your location in a 20' by 20' workspace by setting the following values in your program:
current location X coordinate = fb_pwm07
current location Y coordinate = fb_pwm08
heading (in degrees, 0 - 359) = sensor1
The red point in the workspace is sent to the RC as (pc_p4_x, pc_p4_y). We used it to debug our positioning system on the EDU robot.