tjh+@ANDREW.CMU.EDU (Tom Holodnik) (06/25/91)
Does anyone know of an infrared LocalTalk connection scheme? Does anyone have any experience with it? We have some temporary office space in a trailer parked next to a building (yes, both have windows), and we need a cheap way to connect them to a network, without exposure to problems like lightning and interference. Perhaps we'd have as many troubles with infrared... Does anyone have any expertise here? How reliable is it? Under what circumstances does it work best? Thanks in advance, Tom Holodnik
jim@golden.berkeley.edu (06/27/91)
In article <EcNqZda00WCoQSzBtV@andrew.cmu.edu> tjh+@ANDREW.CMU.EDU (Tom Holodnik) writes: > > Does anyone know of an infrared LocalTalk connection scheme? Does >anyone have any experience with it? We have some temporary office space >in a trailer parked next to a building (yes, both have windows), and we >need a cheap way to connect them to a network, without exposure to >problems like lightning and interference. Perhaps we'd have as many >troubles with infrared... > > Does anyone have any expertise here? How reliable is it? Under what >circumstances does it work best? We use a pair of building-to-building Photolinks from Photonics Corp of Campbell California. Telephone: (408) 370-3033. Email: photonics@applelink.apple.com They mount inside the windows, so are unaffected by the elements. Siting is important. You cannot face them directly into the sun. They should always be at least 7 degrees off of dead-on facing the sun. Keep in mind that the sun moves a lot during the course of the year. The building-to-building units are more expensive than the normal photolinks. List price for a pair is about $4000.00. We got ours for $2350. Logically and topologically, the building-to-building photolinks are opto-isolated repeaters. Since they add about 40 micro-seconds of delay, you cannot use them in conjunction with any other repeaters, unless you put in a bridge and create additional zones. The units are very tolerant of interuption of their beams, but don't plan on using them across a road where delivery trucks will block the beam several times a day. Range is up to 600 feet. We use them to cross a 50-foot driveway. Once properly set up, they work just like localtalk wire, with the caveat above about not adding more repeaters. Photonics supplies superior tech support and is a pleasure to work with. This stuff works and can be a real miracle-maker in certain situations. Jim Bradley, Programmer/Analyst CNR Computer Facility, UC Berkeley jim@cavebear.berkeley.edu