On 24 May 2010 12:48, Robert Benward <[email protected]> wrote: > Jeff, > I just measured one of my " plain serial" cables, it's 2-2 and 3-3. Now I'm > really confused!!! > > "TX" and "RX" have the same pin numbers, so a DCE to DTE needs 2&3 swapped. > Does that mean a DCE to DTE needs a null model, or is that the other way > around?????
Connecting a DTE to a DCE requires a pin for pin straight cable. The labelling of the pins is DTE specific. > I always feel like an amateur when playing with RS-232..... More people have trouble with RS-232 than many other things so your not on your own. Steve > Bob > > > > > ----- Original Message ----- From: "Jeff Hook" <[email protected]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Sunday, May 23, 2010 7:09 PM > Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) > > >> Bob, >> Serial ports have always been tough to get working right. >> I guess I shouldn't call a serial cable, a straight cable. >> I just want to differentiate it, from a null modem cable. >> >> I made up my own cables when I got my Z3805A's >> 9pin on computer end and 25 pin on 3805 >> I wired 2-2, 3-3, and 5-7 and it worked. >> >> Their is also a program called GPS-dos2 that you can download from >> http://www.realhamradio.com/gps-satstat-software.htm >> It runs thru all baud rates, trying to communicat with the 38xx >> You could give that a try. >> >> Jeff >> >> ----- Original Message ----- From: "Robert Benward" <[email protected]> >> To: "Discussion of precise time and frequency measurement" >> <[email protected]> >> Sent: Sunday, May 23, 2010 4:41 PM >> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >> >> >>> Jeff, >>> A plain serial cable will have 2&3 swapped, a "straight through" is 2-2 >>> and 3-3. There were a lot of DB25 to DB25 that were NOT serial cables, they >>> were just 25 pin cable using DB9. >>> >>> Bob >>> >>> >>> ----- Original Message ----- From: "Jeff Hook" <[email protected]> >>> To: "Discussion of precise time and frequency measurement" >>> <[email protected]> >>> Sent: Sunday, May 23, 2010 5:24 PM >>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>> >>> >>>> Receive data is pin 2 on DB9 and 3 on DB25 >>>> Transmit data is Pin 3 on DB9 and 2 on DB25 >>>> A straight thru cable with DB9 on one end and DB25 on the other will >>>> have pins 2 and three crossed >>>> A null modem cable, that is required for a Z3805A, will be pin 2 to pin >>>> 2 and pin 3 to pin 3 >>>> >>>> Jeff >>>> ----- Original Message ----- From: "Stanley Reynolds" >>>> <[email protected]> >>>> To: "Discussion of precise time and frequency measurement" >>>> <[email protected]> >>>> Sent: Sunday, May 23, 2010 3:56 PM >>>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>> >>>> >>>> >>>> >>>> >>>> >>>> ----- Original Message ---- >>>> From: Jeff Hook <[email protected]> >>>> To: Discussion of precise time and frequency measurement >>>> <[email protected]> >>>> Sent: Sun, May 23, 2010 12:42:45 PM >>>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>> >>>> Bob >>>> My 3805 cables look like this >>>> >>>> DB9 DB25 >>>> 2 2 >>>> 3 3 >>>> 5 7 >>>> (Null Modem) >>>> >>>> Jeff >>>> >>>> <snip> >>>> >>>> straight cable is 2 to 2 to 3 to 3 >>>> >>>> null modem would be >>>> >>>> 2 3 >>>> 3 2 >>>> >>>> normal usage would be: >>>> >>>> terminal (straight cable) modem (phone line) modem (straight cable) >>>> computer >>>> computer (straight cable) modem (phone line) modem (straight cable) >>>> computer >>>> >>>> or if no modems : >>>> >>>> terminal (null modem) computer >>>> >>>> As has been mentioned many exceptions to the rule. >>>> >>>> Stanley >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
