brianr@tekig4.TEK.COM (Brian Rhodefer) (12/22/87)
Michael Farren correctly points out the injustice of my knee-jerk loathing of the RS232 "standard". I must agree that the blame truly lies with scoffstandard manufacturers. I am curious about one aspect of the RS232 tragedy though, particularly as I spent a little time on one of my employer's internal standards committees: Why didn't ANSI sue the noncompliant manufacturers who fraudulently claimed that their equipment had "an RS232 interface"? Concocting a good interface is a monumental effort; if I were a committe member, I'd be quite upset at such a desecration. Moreover, ANSI's standards are their "stock in trade"; the present state of RS232 cannot redound very much prestige or credit to the Institute. If they'd aggresively defended their (registered, copyrighted, trademarked, and all that good legal stuff) standards nomenclature from the start, it might have been possible to reliably connect an "RS232 interface" cable to the "RS232 interface" connectors of two pieces of equipment, and confidently expect those two pieces of equipment to communicate. Such is emphatically not possible today. Sorry if all this belongs in another group; I'll shut up now. Idealistically, Brian Rhodefer
haitex@pnet01.cts.com (Wade Bickel) (12/22/87)
If the standards people wanted to do things RIGHT, they would
have made only one connector type.
For instance: make the left half of the connector male, and
the right half female. Make the connector
so that it can plug into itself. Whalla!
No more problems. UniSex cables!
But this is in the nature of American buisness. The only priority
is "how can we sell the most cables?".
I recently bought a Hamilton Beach coffee maker. The caraffe was
designed in such a way that it was impossible to pour coffee from it
without spilling it. I contacted H.B. and they sent me their "fixed"
caraffe (or however you spell it), quit promply. It is a little better,
but also spills.
At first I felt that they (the engineers at Hamilton Beach) must be
a bunch of Idiots. I figure either
a) H.B.'s engineers never took physics.
b) it is intentional.
If it is case b, I figure the water spilling on the warming element
must reduce the life expectancy of the unit??? Am I being too cynical?
I guess I pissed off because the reason I chose it over alternative
machines was the "Buy American, Made in America" sticker on the box.
Thanks, sorry for the
digression,
Wade.
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INET: haitex@pnet01.CTS.COMglee@cognos.uucp (Godfrey Lee) (01/03/88)
In article <2188@crash.cts.com> haitex@pnet01.cts.com (Wade Bickel) writes: > If the standards people wanted to do things RIGHT, they would > have made only one connector type. > > For instance: make the left half of the connector male, and > the right half female. Make the connector > so that it can plug into itself. Whalla! > No more problems. UniSex cables! That's just wonderful! What type of connector do you suggest the box have, male? female? Arrrgh. That is exactly the problem with RS232, which assumes that there are two types of boxes, ie. computers and terminals, and cables are supposed to be pass thru devices (male one end, female the other end, all pins straight thru). This is fine until someone invented PCs, well, actually, someone decided that it would be neat to connect computer to computer! If you look at the consumer market, cables there are much more foolproof. Look at the video cable, look at stereo cable, look at MIDI cable,... All these cables have the same connector on both ends, and it makes no difference which end of the cable plugs into which box! In fact, we used to run a patch panel for a poor man's digital switch, and we use stereo cables and jacks, works great, never get confused. -- Godfrey Lee P.O. Box 9707 Cognos Incorporated 3755 Riverside Dr. VOICE: (613) 738-1440 FAX: (613) 738-0002 Ottawa, Ontario UUCP: decvax!utzoo!dciem!nrcaer!cognos!glee CANADA K1G 3Z4
haitex@pnet01.cts.com (Wade Bickel) (01/06/88)
glee@cognos.uucp (Godfrey Lee) writes: >In article <2188@crash.cts.com> haitex@pnet01.cts.com (Wade Bickel) writes: >> If the standards people wanted to do things RIGHT, they would >> have made only one connector type. >> >> For instance: make the left half of the connector male, and >> the right half female. Make the connector >> so that it can plug into itself. Whalla! >> No more problems. UniSex cables! > >That's just wonderful! What type of connector do you suggest the box have, >male? female? Arrrgh. That is exactly the problem with RS232, which assumes >that there are two types of boxes, ie. computers and terminals, and cables >are supposed to be pass thru devices (male one end, female the other end, >all pins straight thru). This is fine until someone invented PCs, well, >actually, someone decided that it would be neat to connect computer to Perhaps a visual example will suffice: | computer A | | | | OO!! | O = female, ! = male ----------------- !!OO <-- one end of the cable |||| |||| OO!! <-- other end of cable ----------------- | !!00 | <-- note same pattern, | | box is reversed. | computer B | As you can see, all computer would also use the same connector with this scheme. Of course to be reliable all pins would have to be carried across the cable. Thanks, Wade. UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!pnet01!haitex ARPA: crash!pnet01!haitex@nosc.mil INET: haitex@pnet01.CTS.COM
space@pnet02.cts.com (Lars Soltau) (01/07/88)
Of course audio cables are easier to handle. Look how
much pins the have and compare it with the number of pins of an ordinary
null-modem
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INET: space@pnet02.cts.comericb@athertn.Atherton.COM (Eric Black) (01/08/88)
In article <2292@crash.cts.com> haitex@pnet01.cts.com (Wade Bickel) writes: >glee@cognos.uucp (Godfrey Lee) writes: >>In article <2188@crash.cts.com> haitex@pnet01.cts.com (Wade Bickel) writes: >>> If the standards people wanted to do things RIGHT, they would >>> have made only one connector type. >>> [UniSex cables!] >> >>That's just wonderful! What type of connector do you suggest the box have, >>male? female? Arrrgh. > > Perhaps a visual example will suffice: > [pictorial of hermaphroditic connectors] Side note: one common example of such connectors: many brake/signal light connectors for trailers have this general form, although in this case it's not so much to allow for "unisex cables" as it is a polarity safeguard (you can only plug it in one way). You may have seen these things. Back to the point of the cable, since the connector is obviously (!) solvable... One of my previous companies (Functional Automation, Inc.) standardized all our RS-232 cables as follows (the "Functional Standard"): 1 - male-to-female cables were straight-through 2 - male-to-male or female-to-female cables crossed signals as necessary to make them "hermaphroditic" [see modem signal disclaimer in (5) below] 3 - short "adapters" were bolted onto equipment, changing connector sex and jumpering RS-232 signals as necessary to make the cable end of the adapter conform to the Functional Standard (including swapping of TD/RD and buggering of DCD/DTR/DSR/RTS/CTS if required) 4 - as a result, IF it could physically be plugged in, the data signals would WORK 5 - the Functional Standard allows for data interchange (TD/RD), handshake (RTS/CTS), and plug-check (DTR/DSR) signals. These families of signals are sufficient for most (?) uses of RS-232 links OTHER THAN connection to modems (which is, of course, the only thing that the RS-232 definition was originally meant to cover). Connections between modems (Data Communications Equipment, or DCE) and computers or terminals (Data Terminal Equipment, or DTE) uses the RS-232 signals as defined in the standard. Connections other than DTE to DCE follow the Functional Standard, with "standardizing adapters" permanently attached to the equipment as required. Our convenient mnemonic was to assign "sex" to the connector pins. Pins 2, 4, and 20 were male, i.e. data/signal comes OUT, and pins 3, 5, and 6 were female, i.e. data/signal goes IN. The adapters made everything work just fine. The adapters only have to be configured ONCE for each particular equipment example, but making them by hand with a soldering iron can be a pain (but there are cheapie import varieties of a poor-man's breakout patch box nowadays which make it very simple). As a result, we never had to scramble for the "right" cable (the one with the wires moved around for the X piece of equipment), and the RS-232 breakout box (those things are worth their weight in gold, and RS-232 data analyzers are worth their weight in platinum, and heavier besides) is needed only once. --------- "Anyone who uses the terms 'RS-232' and 'standard' in the same sentence has never been in the Real World." -- Eric Black "Garbage in, Gospel out" UUCP: {sun!sunncal,hpda}!athertn!ericb Domainist: ericb@Atherton.COM
peter@nuchat.UUCP (Peter da Silva) (01/11/88)
There is a company that makes connectors that convert from DB25 connectors to (I think 8-pin) phone jacks. The cables are symmetrical, so you can plug anything into anything. The name is something like Western Digital or California Digital or something like that.
ericb@athertn.Atherton.COM (Eric Black) (01/13/88)
In article <526@nuchat.UUCP> peter@nuchat.UUCP (Peter da Silva) writes: >There is a company that makes connectors that convert from DB25 connectors >to (I think 8-pin) phone jacks. The cables are symmetrical, so you can plug >anything into anything. The name is something like Western Digital or >California Digital or something like that. This company is: Nevada Western 930 Maude Ave. Sunnyvale, CA 94086 (408) 737-1600 I heartily recommend them! They make modular (phone-style) patch panels, cables, coax-to-twisted-pair baluns, all sorts of neat stuff. I used the modular panels for wiring up computer rooms and offices in one of my "previous lives". Any terminal or computer could talk to any other, just by patching at the panel, with either a straight-through or a crossed patch cable. The trick is to note that the modular connectors use flat-ish cable, and a half-twist crosses over pairs of signals, if you select the conductors correctly. This "trick" is essentially a more modern version of the one I described in my previous article about RS-232 "standardization" of cables and pinouts, using phone-style modular connectors instead of DB25's. We didn't have ready access to those more convenient connectors in 1978, though -- they were still pretty much confined to TPC. Another advantage of their use of these now-ubiquitous connectors is that vanilla TPC 25-pair cables (with Amphenol connectors) can be used to connect quantities of tty lines in different locations quite conveniently; the patch panels take Amphenol-terminated cables. Connections to the computer tty lines are made with "spider" cables with 25-pair connectors on one end and multiple DB25's on the other. DISCLAIMER: I have no connection whatever to Nevada Western, other than being on their mailing list because I convinced my employer to purchase their products a few years ago, with good results. -- Eric Black "Garbage in, Gospel out" UUCP: {sun!sunncal,hpda}!athertn!ericb Domainist: ericb@Atherton.COM
erd@tut.cis.ohio-state.edu (Ethan R. Dicks) (01/13/88)
In article <526@nuchat.UUCP> peter@nuchat.UUCP (Peter da Silva) writes: >There is a company that makes connectors that convert from DB25 connectors >to (I think 8-pin) phone jacks. The cables are symmetrical, so you can plug >anything into anything. The name is something like Western Digital or >California Digital or something like that. Nevada Western also makes DB25 -> (RJ11, RJ45) products. You can buy versions for 4, 6 and 8 wire cables. I used their stuff at an installation with a patch panel with 5 panels with 8 groups of 8 jacks each (8 jacks @ 6 wires/line fits in a 50 pin TelCo cable) --- that's 320 sockets to crossmatch from terminals to ports. The job was rather easy, since we had proper equipment. I like using flat phone cable and RJ-11 jacks, but the rig is cost prohibitive below about 20-30 plugs -ethan -- Ethan R. Dicks | ###### This signifies that the poster is a member in 2433 N. Fourth St| ## good sitting of Inertia House: Bodies at rest. Columbus OH 43202| ## (614) 262-0461 | ###### "You get it, you're closer."