Wow! I wrote code for a Polhemus system when I was starting out with LabVIEW. This code was a complete rewrite of the (somewhat messy) code I inherited, worked perfectly for the 4-6 years that the Lab continued to run (until the P.I. essentially retired, and the "powers-that-be" chose to let a superbly-designed system for doing Sound Localization experiments using human subjects, using movable sound sources controlled by robotic arms, be abandoned).
I don't remember the model of the Polhemus, but I do remember that it used a strange encoding scheme that used transmission of a binary data stream over RS-232, readable in LabVIEW using VISA. However, as the data were not in ASCII, we had to read individual bytes, looking for the "start" (or was it the "end") flag, then start reading the (12?)-byte stream, packing and unpacking the bits to get the 6 spatial and angular parameters being returned.
I just went looking for this old code. I found a document I wrote in 2010 that describes the early stages of migrating the "old code" that used the Polhemus over a 38.4 kBaud serial port. To get the 120 updates/second that the Polhemus was sending us, I calculated that each "message" should be no more than 32 bytes -- transmitting the data in ASCII took about 50 characters to sed the header and 6 coordinates, while the proprietary binary format took only 16 bytes (a three-character header and 6 2-byte coordinates), which is why (I now recall) we went "binary".
Unfortuately, this is where the Document ends. I don't think I have the old Manual, but I might be able to find the old code ...
Bob Schor
