On Sun, 30 Nov 2014 09:46:51 -0700, Don Y <this@is.not.me.com> wrote:>The challenge is coming up with a suitable connection without requiring >new castings. There are some tight physical space limitations that >effectively rule out anything "revolutionary".What shape and size hole do you currently have in the odd shaped chassis? Can it be enlarged or re-punched? What degree of environmental protection do you need? <http://en.wikipedia.org/wiki/IP_Code> If you can enlarge the hole, this might work: <http://www.digikey.com/product-highlights/en/waterproof-rj45-series-plugs-and-jacks/50458> I used similar connectors for outdoor wi-fi access points. Plenty of other options available: <https://www.google.com/search?q=waterproof+rj45&tbm=isch> Before such made-for-purpose RJ-45 connectors were available, I just used a pigtail with a plug or jack at the end and protected it with a spark plug boot. Ugly, but functional. This should be better: <http://www.digikey.com/product-detail/en/PX0777%2FUTP/708-1364-ND/1980722> <http://media.digikey.com/Photos/Bulgin%20Photos/PX0777%5EUTP.JPG> If you already have a rectangular hole punched in the chassis, and need to reduce it to a 1/4" dia round hole for CAT5e (or larger for a grommet), one of these and some RTV might work: <http://www.digikey.com/product-detail/en/BPE-RJ45-01/BPE-RJ45-01-ND/3811705> I suggest you bring out all 8 wires as you might later find PoE and 1000baseT useful. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
RJ45/8P8C alternatives
Started by ●November 30, 2014
Reply by ●November 30, 20142014-11-30
Reply by ●December 1, 20142014-12-01
On 2014-11-30, Don Y <this@is.not.me.com> wrote:> Hi, > > I have an irregular-shaped (metal) enclosure to which an ethernet connection > must be mated. > > I can afford to run at 10BaseT speeds -- though would REALLY REALLY prefer > 100BaseTX (-T2 is not a practical option). > > Connection must be weather-resistant (sheltered location; not "indoor"). > > The challenge is coming up with a suitable connection without requiring > new castings. There are some tight physical space limitations that > effectively rule out anything "revolutionary". > > The traditional RJ45 8P8C doesn't seem like it would fare well in > the environment and would also be tedious to machine *into* the > case.http://www.ttabconnectors.com/pdf/AB_Specification_610_Issue_2.pdf possibly overkill, but those sort of things are available from several vendors, be sure to use UV resistant cable,> Abandoning it for a more physically convenient connector > leaves me uncertain as to how "untwisting" all those connections > *at* the connector would compromise the signal path.St 10Mbps, the signals are 10m long (manchester coding: 2 signals per bit) you can untwist quite a bit before it hurts enough to stop working. -- umop apisdn
Reply by ●December 4, 20142014-12-04
Hi Joe, On 11/30/2014 10:27 AM, Joe Chisolm wrote:> On Sun, 30 Nov 2014 09:46:51 -0700, Don Y wrote: > >> I have an irregular-shaped (metal) enclosure to which an ethernet >> connection must be mated.>> Connection must be weather-resistant (sheltered location; not "indoor"). >> >> The challenge is coming up with a suitable connection without requiring >> new castings. There are some tight physical space limitations that >> effectively rule out anything "revolutionary". >> >> The traditional RJ45 8P8C doesn't seem like it would fare well in the >> environment and would also be tedious to machine *into* the case. >> Abandoning it for a more physically convenient connector leaves me >> uncertain as to how "untwisting" all those connections *at* the >> connector would compromise the signal path. > > Modern PHYs are so much better than pulling the signal out of the crap.Do you think that true even on the deeply embedded devices? E.g., SoC's with MAC & PHY on the same die as the processor?> As a point of reference, we have a product that has to switch between a > front RJ45 and a back plane connector. There is a RJ45 on a backplane > that feeds to a .156 Sullins edge connector. A board plugs into that > and has about 10" of diff pair to a TI ethernet mux chip to a SMC > LAN8720 phy and 100Mb is no problem. So we go > cable->RJ45->edge connector->lan mux->phySo, *through* the edge connector is your "least controlled" point of transmission? I.e., you still try to maintain signal integrity on either side of that connection -- you're not *casually* treating the signals past the connector(s)?> Can you do some type of a pigtail coming out of the box to a weather > tight connector? Maybe: > RJ45-5EWTP-CS-CBL-8I and RJ45-5EWTP-CBI've thought of the pigtail approach, etc. I'm just questioning whether the RJ45 is "appropriate" in any form in this sort of environment. I.e., I can see using a weatherproof/resistant RJ45 to allow COTS devices to mate with it. But, given that this connection is dedicated to this device, can I avail myself of other "more effective" means of connection? E.g., "serial ports" started out behind DB25's... then DB9's... but you'll also find them as "three pads on a PCB" in many places. Nothing about a "serial port" (read: 100BaseTX) connection *requires* a particular connector!
Reply by ●December 4, 20142014-12-04
On 11/30/2014 12:55 PM, whit3rd wrote:> On Sunday, November 30, 2014 8:47:03 AM UTC-8, Don Y wrote: >> Hi, >> >> I have an irregular-shaped (metal) enclosure to which an ethernet connection >> must be mated. >> >> I can afford to run at 10BaseT speeds -- though would REALLY REALLY prefer >> 100BaseTX (-T2 is not a practical option). >> >> Connection must be weather-resistant (sheltered location; not "indoor"). > > There are systems with weather-resistant caps (and threaded shrouds) that > will take rain. You won't like the prices. > > At 10baseT speed, you might consider falling back to 10base200 (i.e. thinwire) > and use a BNC connector! There can be a media converter in some sheltered > location at the other end of the link, I hope.That was why I offered the 10Mb speed as a potential consideration. I'd already been thinking about going the BNC route (or any other "2 conductor" approach) and exploiting the sloppiness that the lower data rate afforded. But, I *really* would like to remain at 100Mb speeds (as I can then use the channel for other operations beyond it's minimum stated requirements).> Weather-sealing a WiFi connection might be easiest.I'd still have to deal with getting power into the boxes (I've not mentioned this as it can always be addressed via a secondary connector -- its requirements being trivial when contrasted with the data path).
Reply by ●December 4, 20142014-12-04
On 11/30/2014 8:37 PM, Jeff Liebermann wrote:> On Sun, 30 Nov 2014 09:46:51 -0700, Don Y <this@is.not.me.com> wrote: > >> The challenge is coming up with a suitable connection without requiring >> new castings. There are some tight physical space limitations that >> effectively rule out anything "revolutionary". > > What shape and size hole do you currently have in the odd shaped > chassis? Can it be enlarged or re-punched?None.> What degree of environmental protection do you need? > <http://en.wikipedia.org/wiki/IP_Code>As I said: "Connection must be weather-resistant (sheltered location; not "indoor"). I avoided claiming "weather-PROOF". The locations will be sheltered and *generally* protected from the elements (direct sun, direct precip, direct wind). However, no protection from temperature extremes, humidity, indirect sun/wind/precip, etc. (hence my "not 'indoor'" claim)> If you can enlarge the hole, this might work: > <http://www.digikey.com/product-highlights/en/waterproof-rj45-series-plugs-and-jacks/50458> > I used similar connectors for outdoor wi-fi access points. Plenty of > other options available: > <https://www.google.com/search?q=waterproof+rj45&tbm=isch>There is no *need* to stick to the RJ45 form factor. I think that severely limits the choices and complicates the fitting of the connector to the enclosure. E.g., why are there mini-USB connectors instead of forcing ALL such connections to adopt the standard A/B connectors? (Ans: because the mini connectors can be deployed in locations that the standard ones can't!)> Before such made-for-purpose RJ-45 connectors were available, I just > used a pigtail with a plug or jack at the end and protected it with a > spark plug boot. Ugly, but functional. This should be better: > <http://www.digikey.com/product-detail/en/PX0777%2FUTP/708-1364-ND/1980722> > <http://media.digikey.com/Photos/Bulgin%20Photos/PX0777%5EUTP.JPG> > > If you already have a rectangular hole punched in the chassis, and > need to reduce it to a 1/4" dia round hole for CAT5e (or larger for a > grommet), one of these and some RTV might work: > <http://www.digikey.com/product-detail/en/BPE-RJ45-01/BPE-RJ45-01-ND/3811705> > > I suggest you bring out all 8 wires as you might later find PoE and > 1000baseT useful.That;s why I mentioned 8P8C and not just "RJ45". But, if that requirement complicates the connector choice, I can move the power off the connector and handle it in other ways (power is relatively easy and tolerant of a wide variety of connection methodologies)
Reply by ●December 4, 20142014-12-04
On Wednesday, December 3, 2014 10:32:11 PM UTC-8, Don Y wrote:> "Connection must be weather-resistant (sheltered location; not "indoor"). > I avoided claiming "weather-PROOF". The locations will be sheltered and > *generally* protected from the elements (direct sun, direct precip, direct > wind).One can put a split-rubber grommet facing downward, route a cable up through, and into a sheltered RJ-45 socket, but there's still the weather-tolerance of the cable to consider. I'm not clear on the availability of exterior grade CAT-5/6 cables (sunlight, possum, raccoon, and in some locations rabbit and deer tolerant). I've seen rugged-duty (seismometer) connectors that wouldn't have any trouble with weather, but there were oddball cables involved, I wouldn't know where to get controlled-impedance outdoorsy versions for Ethernet.
Reply by ●December 4, 20142014-12-04
On 12/4/2014 1:18 AM, Don Y wrote:> Hi Joe, > > On 11/30/2014 10:27 AM, Joe Chisolm wrote: >> On Sun, 30 Nov 2014 09:46:51 -0700, Don Y wrote: >> >>> I have an irregular-shaped (metal) enclosure to which an ethernet >>> connection must be mated. > >>> Connection must be weather-resistant (sheltered location; not "indoor"). >>> >>> The challenge is coming up with a suitable connection without requiring >>> new castings. There are some tight physical space limitations that >>> effectively rule out anything "revolutionary". >>> >>> The traditional RJ45 8P8C doesn't seem like it would fare well in the >>> environment and would also be tedious to machine *into* the case. >>> Abandoning it for a more physically convenient connector leaves me >>> uncertain as to how "untwisting" all those connections *at* the >>> connector would compromise the signal path. >> >> Modern PHYs are so much better than pulling the signal out of the crap. > > Do you think that true even on the deeply embedded devices? E.g., > SoC's with MAC & PHY on the same die as the processor? > >> As a point of reference, we have a product that has to switch between a >> front RJ45 and a back plane connector. There is a RJ45 on a backplane >> that feeds to a .156 Sullins edge connector. A board plugs into that >> and has about 10" of diff pair to a TI ethernet mux chip to a SMC >> LAN8720 phy and 100Mb is no problem. So we go >> cable->RJ45->edge connector->lan mux->phy > > So, *through* the edge connector is your "least controlled" point of > transmission? I.e., you still try to maintain signal integrity on either > side of that connection -- you're not *casually* treating the signals > past the connector(s)? > >> Can you do some type of a pigtail coming out of the box to a weather >> tight connector? Maybe: >> RJ45-5EWTP-CS-CBL-8I and RJ45-5EWTP-CB > > I've thought of the pigtail approach, etc. I'm just questioning whether > the RJ45 is "appropriate" in any form in this sort of environment. > I.e., I can see using a weatherproof/resistant RJ45 to allow COTS > devices to mate with it. > > But, given that this connection is dedicated to this device, can I > avail myself of other "more effective" means of connection? E.g., > "serial ports" started out behind DB25's... then DB9's... but you'll > also find them as "three pads on a PCB" in many places. Nothing > about a "serial port" (read: 100BaseTX) connection *requires* a > particular connector!My WISP unit is designed for outdoor use. They use an RJ-45 connector. Looks like they do it like the phone company. The connector is behind a cover which seals around the cable coming in. Doesn't look like the connector is anything special. -- Rick
Reply by ●December 4, 20142014-12-04
On 12/4/2014 1:59 AM, whit3rd wrote:> On Wednesday, December 3, 2014 10:32:11 PM UTC-8, Don Y wrote: > >> "Connection must be weather-resistant (sheltered location; not "indoor"). >> I avoided claiming "weather-PROOF". The locations will be sheltered and >> *generally* protected from the elements (direct sun, direct precip, direct >> wind). > > One can put a split-rubber grommet facing downward, route a cable up through, and > into a sheltered RJ-45 socket, but there's still the weather-tolerance of the > cable to consider. I'm not clear on the availability of exterior grade CAT-5/6 > cables (sunlight, possum, raccoon, and in some locations rabbit and deer > tolerant). > > I've seen rugged-duty (seismometer) connectors that wouldn't have any > trouble with weather, but there were oddball cables involved, I wouldn't know > where to get controlled-impedance outdoorsy versions for Ethernet.My WISP guy should be here in the next week or so to actually put my WISP unit outside. I will ask him what cable they use. When he gave me my unit with a PoE cable to the power head he said not to mix the cable with others. But he seemed to be saying it was about the shielding more than the weatherproofing. -- Rick
Reply by ●December 4, 20142014-12-04
On 12/3/2014 11:59 PM, whit3rd wrote:> On Wednesday, December 3, 2014 10:32:11 PM UTC-8, Don Y wrote: > >> "Connection must be weather-resistant (sheltered location; not "indoor"). >> I avoided claiming "weather-PROOF". The locations will be sheltered and >> *generally* protected from the elements (direct sun, direct precip, direct >> wind). > > One can put a split-rubber grommet facing downward, route a cable up through, and > into a sheltered RJ-45 socket, but there's still the weather-tolerance of the > cable to consider. I'm not clear on the availability of exterior grade CAT-5/6 > cables (sunlight, possum, raccoon, and in some locations rabbit and deer > tolerant).Cable isn't a problem. My microwave link has a length of CAT5 cable across the roof to the dish. Critters shouldn't be a problem, either. And, I could always slip the cable through an armored jacket if that were the case. But, any sort of connector would have to be mounted on the skin of the enclosure. There's no room to extend inside (and globbing something on the exterior into which a connector could hide would alter the cosmetics). Either some small, compact connector on the skin or a cord dangling from it (which means I need a place to which to connect THAT)> I've seen rugged-duty (seismometer) connectors that wouldn't have any > trouble with weather, but there were oddball cables involved, I wouldn't know > where to get controlled-impedance outdoorsy versions for Ethernet.The connector is the bigger issue. E.g., ensuring it doesn't become a home for insects or their egg caches (spiders, leaf cutting wasps, etc.) if "unconnected" (while the equipment is still deployed -- can't count on folks to "button up" any "exposed" connector while not in use).
Reply by ●December 4, 20142014-12-04
On 11/30/2014 5:59 PM, Ralph Barone wrote:>> The traditional RJ45 8P8C doesn't seem like it would fare well in >> the environment and would also be tedious to machine *into* the >> case. Abandoning it for a more physically convenient connector >> leaves me uncertain as to how "untwisting" all those connections >> *at* the connector would compromise the signal path. > > Optical maybe?Yes, another possibility. Handle power with a "traditional" connector and then run fiber through the skin. But, that either means a media converter nearby *or* run the whole drop as fiber (I think it may be too late for that sort of change)
