I have a Trimble Pathfinder XL Pro Differential GPS unit.

In NEMA mode, this unit will update the current position at up to 1HZ.

I need to get position data updates at least 5 times per second
wihtout loosing decimeter precision.

I am hoping there is either a way to (1) set the unit to output
updates at faster than 1HZ, or (2) a way to request the current the
position from the unit in a way where I could send 5 requests per
second.

I'll accept any answer that results in me getting decimeter precise
location info from this unit at 5HZ while moving at up to 10 m/s.

Looking into the equipment specifications on Trimble's website it
appears that if you wish a higher update rate you will have to have
custom firmware written.  This particular GPS unit does not appear to
speak anything but RTCM and NMEA.  Other GPS units usually have a
proprietary protocol to speak with software or hardware made by the
same company and provided increased functionality which may allow for
faster updates.

I think the unit does know some other sort of propriatary 2-way
protocol becuase, for example, the "Pathfinder Controler" software
package can change internal configuration settings and display interal
status info of a connected unit. I don't know if that protocol
includes any sort of "Calcualte and output position NOW" command, but
it seem like it might.

Thanks.