Xref: utzoo misc.wanted:1719 comp.dcom.lans:978
Path: utzoo!lsuc!ncrcan!brian
From: brian@ncrcan.Toronto.NCR.COM (Brian Onn)
Newsgroups: misc.wanted,comp.dcom.lans
Subject: Re: PC as RS232 Data Analyzer
Message-ID: <581@ncrcan.Toronto.NCR.COM>
Date: 29 Jan 88 14:37:37 GMT
References: <2473@emory.uucp> <1063@percival.UUCP>
Reply-To: brian@ncrcan.Toronto.NCR.COM (The Super User)
Organization: NCR Canada Ltd., Mississauga, Ontario
Lines: 38

In article <1063@percival.UUCP> gary@percival.UUCP (Gary Wells) writes:
>
>In article 2600 of misc.wanted Ken Mandelberg asks:
>
>>In the serial RS232 world, I have seen a number of special purpose data
>>analyzers, which seem quite expensive. Although I suppose they do other
>>things, a big piece of their functions is just accurately logging the
>>traffic in both directions, and triggering on certain sequences. It
>>seems to me that a PC with two serial interfaces could do much the same
>>thing, and that the software is not especially tricky.
>
>>Has anyone seen a product of this sort?
>
>You don't even need 2 ports, just one.  Most EIA (RS-232) drivers will handle
>a "bridged" connection, that is, will source multiple recievers.  Just build
>yourself a Y cable, and run your PC communications program in capture mode.
>If possible, have it display, not act upon, control sequences.  


But would you not miss some data?? I mean, to acurately monitor data and 
hardware lines from both the DTE and DCE under test, your PC would need a
passive port, made up of only *line receivers*.  Every PC I have worked with 
has had both line drivers and line receivers on it's serial port.  Bridging two
drivers is sure to affect the real data.

I have seen some PC serial ports which are switch selectable to be 
configured as either a DTE or DCE.  Perhaps if the hardware has enough 
receivers, then it could be set up so that it has some lines set up as DCE and
others set up as DTE, to provide a receiver only interface.

Of course, some special software would be required.

So what is the net's concensus on the above?? Are most serial ports
configurable as mentioned?  If they are, then a software only solution is
feasible. 

Brian.