RE: SJTP: Minutes from 08-May meeting
Well, I agree with both of your arguments. But I still have a problem in that I don't know if the test procedure will work under modulation (as well as additional unnecessary testing). My own tests were done without implementing FOTP 203 using a camera which is the intended methodology. I will ask the 2.2.1 group for additional insight to see if they think it actually will work.
So let me try a different line of argument. Encircled flux is a component (i.e. transceiver), not a system test for which we already have a test procedure called out, namely FOTP 203. We have a number of other component specifications which do not seem to require a test procedure description. So then why does encircled flux need to have a description added? I have tested 1 Gb transmitters without modulating them (which by the way I don't remember seeing any difference there either, with versus without modulation).
Again, I apologize if I am missing something. I am not trying to be argumentative, but rather trying to avoid potential problems in the future and possibly additional unnecessary costs from testing transceivers.
mike
> ----------
> From: jmw[SMTP:jmw@xxxxxxxxxxx]
> Sent: Tuesday, May 08, 2001 8:33 PM
> To: Bill Reysen
> Cc: Hackert, Michael J; serialpmd; 'Ben Brown'
> Subject: Re: SJTP: Minutes from 08-May meeting
>
> i agree that tests which are done with anything that simulates a real end-use
> condition will return better indication than any DC condition (i don't have data
> either, it's just a combination of logical reasoning and personal experience).
>
> but for this effort, isn't it also true that you must either describe a set of common
> electrical characteristics for a transmitter or describe a common set of drive
> conditions? i expect the latter is a better choice, but don't know whether or not
> the group is already working on that.
> --
> jmw
>
> At 04:58 PM 08-05-01 -0600, Bill Reysen wrote:
>
>
>
> [...]It also stands to reason that a modulated
> measurement would be a more accurate indicator of link perfromance but I don't
> know if data exists to support this.
>
> "Hackert, Michael J" wrote:
>
> > Ben,
> >
> > Hi. Having only scanned minutes, I hate to sound ignorant. However, I was
> > wondering if there was really a need to have the source modulated during the
> > encircled flux measurements as implied in your slide 3.
> >
> > TIA 2.2.1 never did any experimentation with modulation of the transceivers
> > during our development process. I have done some tests myself which says
> > that the difference if any is hard to detect. Not being a manufacturer of
> > transceivers and lacking that expertise, I will concede if the experts say
> > that it is necessary. However, I am reluctant to add a requirement if it is
> > really only being included as a nice to have.
> >
> > mike
> >
>
>