This subject is somewhat timely for a project I'm dealing with now; an ISDN S/T and U interface tester. The S/T port for end-user access is well defined. However, based on the feedback I get from our designers, the U interface has no firm electrical spec, making it hard to determine with certainty the isolation/insulation requirements. We're doing our own safety tests under the supervision of a TUV engineer. I find the lack of a specification for the U interface - hard to fathom.
Eric Lifsey Compliance Engineer/Manager National Instruments "Victor L. Boersma" <[email protected]> on 08/02/98 05:03:03 PM Please respond to [email protected] To: "INTERNET:[email protected]" <[email protected]> cc: (bcc: Eric Lifsey/AUS/NIC) Subject: ADSL modem - safety & EMC > I'm into a new project: an ADSL board, installed in the CO and connected to > ISDN lines. There is an ETSI document that gives all ISDN interfaces (in Europe) and what safety requirements out of EN 60950 apply at each interface. Only thing I am not sure of after all those years (ISDN is a bit of an old technology) is whether it addresses interfaces inside the Central Office. It was intended to cover interfaces at the Customer Premises, as I recall. Sorry but don't have the number of that document any longer. In any event, safety and EMC standards are not concerned with technologies, so if you apply 60950, you should be alright as long as you know what to expects at the interfaces that you work. E.g., does your modem sit behind the CO carbon protectors and heatcoils ? Do you know what degree of isolation/protection from lightning and overvoltages those provide in the types of Central Offices that you will deploying your devices ?? I may be proven wrong, but I doubt that you can get that info at any WEBsite. I also doubt that you will get a uniform pan-European answer. I suggest that you go back to your marketing people and ask them what their target markets are before going on a wild goose chase. Ciao, Vic
