edw@wells.UUCP (Ed Wells) (02/19/90)
In article <431@skipper.dfrf.nasa.gov>, rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) writes: > > It seems that each headset would need an independent > xmit frequency, but all could share a common recv. > frequency. This would also allow "listen only" > headsets. Why? Just have the transmitters fire up like their RF counterparts. Have the transmitter work on a VOX (Voice operated transmitter) or on a PTT (Push to Talk). -- ========================================================================= Edward E. Wells Jr., President Voice: (215)-943-6061 Wells Computer Systems Corp., Box 343, Levittown, Pa. 19058 {dsinc,francis,hotps,houxl,lgnp1,mdi386,pebco}!wells!edw
tob@cbnewsk.ATT.COM (ted.o.burger) (02/21/90)
> In article <6313@ncar.ucar.edu> hpoppe@bierstadt.scd.ucar.edu (Herb Poppe) writes: > >How about 2-way data communication (half or fuyll-duplex)? > I think it's been done. Some HP calculators have the ability > to send data to the little HP printer via IR beam. The printer > checks for data corruption, and, if it detects an error, requests > a retransmission. Of course, this system requires a clear > line of sight between sender and receiver, which would be a Bob Thr HP system is NOT a two way system. The data is encoded in a (almost) full error correcting format. Their goal was to provide the link with minium cost to the calculator so they could include it on the maximum number of calculators. The calculator just has a single diode and the reciever is in the printer. Only the people who want the printer have to spend the bucks to get the IR receiver. Ted