Re: RS-232 port genders

[Jerry <awanderin@yahoo.ca>]

schmidtd <schmidtd@my-deja.com> writes:

> On Jun 21, 12:37 pm, schmidtd <schmi...@my-deja.com> wrote:
>> On Jun 21, 12:33 pm, datajerk <dataj...@gmail.com> wrote:
>> > On Jun 21, 9:47 am, datajerk <dataj...@gmail.com> wrote:
>> > I failed to mention that the SSC came with a female DB25.
>>
>> From Wikipedia on RS-232, FWIW:
>>
>> "RS-232 devices may be classified as Data Terminal Equipment (DTE) or
>> Data Communication Equipment (DCE); this defines at each device which
>> wires will be sending and receiving each signal. The standard
>> recommended but did not make mandatory the D-subminiature 25 pin
>> connector. In general and according to the standard, terminals and
>> computers have male connectors with DTE pin functions, and modems have
>> female connectors with DCE pin functions. Other devices may have any
>> combination of connector gender and pin definitions. Many terminals
>> were manufactured with female terminals but were sold with a cable
>> with male connectors at each end; the terminal with its cable
>> satisfied the recommendations in the standard."
>
> One thing I forgot to mention... since the SSC can play both a DTE and
> a DCE role, either gender would have made about as much sense as the
> other.  The "standard" ambiguity was among the reasons why anyone who
> sold cables also sold gender changers. :-)

I always hated RS-232 et. al. because of the variety of possible
connection scenarios, both physical and electrical (and still hate them
since I work in a data center and occasionally have to connect to a
serial port on some device that is wedged).  I think the old adage that
"the thing that's so great about standards is that there are so many to
choose from", holds especially true for RS-232.  For something as
conceptually simple as serial communications, RS-232 made it into a
black art.


--
Jerry    awanderin at yahoo dot ca