> It's a calibration system, and as such it requires high reliability. > > Networking and addressing leaves the system open to problems such as > if one RS485 chip goes short circuit, for example, it will bring the whole > network down and screw up the (lengthy) calibration process > > Therefore IT MUST be designed this way, unless you can think of anything > better > > Separating each channel isolates unit specific problems to just that channel
Actually, no it doesn't because you still have to have an addressing mechanism for the multiplexer that still leaves the system open to single point failures. Note that Ethernet systems have a very high reliability. What is it about your RS-485 system that leads you to expect failures? Is it a harsh environment? Are the cables and connections subject to a lot of handling and ESD events? Since you need RS-485 characteristics in and out of this mux, that means 121 receiver/transmitters because the analog switches don't have the proper characteristics or ESD immunity for the job. I just took a quick look at Google and several companies make RS-485 multiplexers. You might want to check some of them out before building one of your own. -=-=-=-=-=- "http://www.dibsplace.com/design/"; -=-=-=-=-=- DIBs Electronic Design | Dave Baldwin Adapt and overcome. | Buy a book and read it. -=-=--=-=--=-=--=-=--=-=-=-=--=-=--=-=--=-=--=-=--=-=-=-=- -- Author: Dave Baldwin INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
