re protection of serial rs lines martin john gregory mgregory flash pax tpa com au wrote i ve started to look at some devices doing serial data transmission over fairly decent distances in fairly noisy environments and have seen a variety of schemes for protecting the rs transceivers and the rest of the circuit from transients on the serial lines i m left wondering what is the best way of doing this how necessary is it stuff deleted what is the wisdom on this out there ta martin from what i know protection is necessary esp if you plan to route the cables into an unknown environment out of your control things like accidental shorts between the signal lines and power cables or even lightning strikes are very likely and i don t think you like to see the sight of your computer going up in smoke even ethernet cards are protected i ve looked at the one in my pc and the connector is protected by a gas discharge tube but if you plan to use the serial cables for internal routings i e in controlled environments it should be reasonably safe not to have them suggestion look in the rs data book they have several rs transceivers that have overvoltage protection among them include the lt lt and max and max the maxims are suppose to be electrically isolated ones but still need opto isolators to work don t ask me why i ve never used them before another alternative is an rs surge protector two are listed in the rs catalogue if you need additional info i e stock nos just e mail me soh kam yung engp nusunix nus sg
