Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!agate!golden.berkeley.edu!jim From: jim@golden.berkeley.edu Newsgroups: comp.protocols.appletalk Subject: Re: Wireless LocalTalk? (Photolink) Keywords: Photolink Message-ID: <1991Jun27.160915.16225@agate.berkeley.edu> Date: 27 Jun 91 16:09:15 GMT Article-I.D.: agate.1991Jun27.160915.16225 References: Sender: usenet@agate.berkeley.edu (USENET Administrator) Distribution: usa Organization: U.C. College of Natural Resources Lines: 49 In article 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