RJ45, RJ12, RJ14 cables, straight-through or crossover?

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
 RJ45 network cables come in straight-through, and
 in crossover versions.  Does straight-through in a
 patch cable mean that pin 1 in goes to pin 1 out?

 What about everyday telephone cables?  A flat cable,
 with wires going straight into the plug on each end.
 Physically, it looks like the very definition of
 straight-through.  But does pin 1 in go to pin 1 out?
 NO!!  Since the two plugs face in opposite directions,
 pin 1 goes to pin 4, and etc.  Pin 1 to pin 1, would
 require a wire crossover or a 180-degree cable twist.

 What about the straight-through RJ45 network cables?
 Yes!  These DO have pin 1 in going to pin 1 out.  And
 it's the crossover type that has pin 1 to pin 8, etc.

 I thought about this at 3 AM, looked at a telephone
 cable, and changed the PCB layout for my beehive's
 five-sensor I2C jacks.  But wait, are RJ11 RJ14 6P4C
 phone and RJ12 6P5C data cables different?  Checking,
 Yes!  An RJ11 voice cable can worked reversed, but
 an RJ12 data straight-through is pin 1 to pin 1.
 Some sellers of RJ11 RJ14 cables let you specify to
 get straight pin 1 to pin 1, or "reversed".

 Sheesh, changing my PCB jack wiring back again.


--  
 Thanks,
    - Win

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it

  Most ports have self negotiation Hdw at one end or the other or both  
and they auto handshake.

  But to answer you query:

Googled "Gb ethernet wiring"  and the very first picture has all your  
answers.

<https://www.google.com/search?q=Gb+ethernet+wiring

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
On 12 May 2019 07:38:20 -0700, Winfield Hill

Quoted text here. Click to load it

Most ethernet/RJ45 gadgets nowadays are agnostic to the crossover
situation; they work either way.

In non-ethernet situations, like RS485 or such, I buy non-crossover
RJ45 CATx cables, pin1 to pin1, just like most cable assemblies. I
find that easier to understand on schematics.

I also find that I discover things at 3AM, or sometimes later in the
shower.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
Ethernet cross-overs swapped pairs.

Voice cables by default swapped polarity within the pair.

And 8-conductor telephone cables were a crap-shoot as to which
way they were built, adding to the fun.

Telco cables cared about polarity so the (first generation) DTMF
pads would work. I wonder if it even matters if an Ethernet
cable has backwards polarity; not sure.


--  
A host is a host from coast to snipped-for-privacy@nrk.com
& no one will talk to a host that's close..........................
We've slightly trimmed the long signature. Click to see the full one.
Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
On 12 May 2019 07:38:20 -0700, Winfield Hill

Quoted text here. Click to load it

"Standards are a good thing.  Every company should have one."
I forgot who said that.

Before you invent a new wiring standard for I2C over RJ11 connectors,
perhaps you might want to search for prior art[1].

Finding the right connector for I2C
<https://hackaday.io/project/26823-lameboy-another-esp12-handheld/log/70606-finding-the-right-connector-for-i2c

Is there any definitive I2C pin-out guidance out there? Not looking
for a "STANDARD"
<https://electronics.stackexchange.com/questions/47056/is-there-any-definitive-i2c-pin-out-guidance-out-there-not-looking-for-a-stand

6P6C I2C Connector Standard
<https://www.iascaled.com/store/6P6C-I2C

I2C Bus Connectors & Cables
<https://www.i2cchip.com/i2c_connector.html

I2C - Community Recommended Pinout DRAFT 4th Feb 2015
<http://samepins.github.io/doc/i2c.html
<http://samepins.github.io/doc/i2c%20&%20one-wire.html

There are probably more such "standards".

Drivel:  In the distant past, I was marginally involved in trying to
cram the 25 pin RS-232 wiring into an 8 pin RJ-45 connector while
having the pin numbering reversible between DTE and DCE.  Not my idea
of fun.  To make everyone happy, we had to use an (optional) 10 pin
RJ-50 connector.  


[1] If it does something disgusting when reversed, like destroy the
bus transceivers, you can blame whomever originally contrived the
wiring standard.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
wrote:

(...)
Are you doing something like this?
<http://hivetool.net
<http://wiki.hivetool.org/HiveTool.org

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it

  That is pretty cool.

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
On Sun, 12 May 2019 23:04:20 +0000 (UTC),
snipped-for-privacy@decadence.org wrote:

Quoted text here. Click to load it


Yep.  Some of the details on how bee hive monitor is used are
interesting.  I didn't know that the life of a bee hive is so
complicated:
Hive Management
<http://wiki.hivetool.org/Hive_Management

Instead of one connector for each PCB designers idea for creative I2C
wiring and pinout, he simply crimps the cable to match his wiring
standard.  See photos of PCB at:
<http://wiki.hivetool.org/Hardware:_Hive_Interface_Board_1.0
and wiring at:
<http://wiki.hivetool.org/Hardware:_Sensor_Wiring
I've been through the DHT22 humidity sensor color coding mess with my
various weather stations.  

Methinks he made a mistake with the TSL2591 Lux Sensor wiring, which
shows that the cable is wired for "standard" telco crossover wiring,
which might a problem since the 3.3v and ground are on opposite ends
of the RJ14 connector and reversing them might become a smoke test. My
rule of thumb is that if it's used for telco, then a "rollover" or
mirror image connector wiring should be used.  For everything else, I
wire it pin 1 to pin 1.  

Oops.  I don't think the author thought this out very well:
<http://wiki.hivetool.org/Hardware:_Sensor_Wiring#TSL2591_Lux_Sensor
    Consider cutting a 10 or 12' cord in half for two  
    sensors, crimping will be unnecessary.
If he uses "standard" telco flat cable, cutting it in half will result
in two different (mirrored) RJ11 wiring configurations for each half.
I suspect he wrote that before actually trying it.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
Jeff Liebermann wrote...
Quoted text here. Click to load it
 See DropBox for my six-channel sensor board:
https://www.dropbox.com/sh/w1xbcwovma602he/AADzRhQgieifJ9z1FoSscDrHa?dl=0

 RIS-788_BME280+Si1145+LED.JPG shows daughter
 PCB with T + RH + mBar pressure, plus three
 light channels, plus a bright LED heartbeat.
 That was last year's I2C sensor board; this
 year's new I2C board adds five ICs, with 12
 channels, located in the middle of the hive,
 see TH-stick_sensors-only_3D.PNG


--  
 Thanks,
    - Win

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it
H

  Outdoor?

  Te connectivity.

 "SLIMSEAL"

https://www.te.com/usa-en/plp/slimseal-miniature-
connectors/Xpmyza.html

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
snipped-for-privacy@decadence.org wrote...
Quoted text here. Click to load it

 Last year's I2C board is inside the monitor box,
 exposed to the outside.  This year's additional
 I2C sensor board is in the middle of the hive.

Quoted text here. Click to load it

 Very interesting, I hadn't found that one.  But,
 what's with only up to 3 positions available?


--  
 Thanks,
    - Win

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it
https://www.dropbox.com/sh/w1xbcwovma602he/AADzRhQgieifJ9z1FoSscD
Quoted text here. Click to load it
connectors/Xpmyza.
Quoted text here. Click to load it

  automotive target 'demographic'.  I didn't notice.

  OK so somebody needs to tell them we need more positions.  

  I looked.  Their ip67 unit with 8 positions is a CAT7A unit for  
long haul and is a couple hundred each.  Wow.

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it
_Lux_Senso
Quoted text here. Click to load it

  With so many units involved, buying a set of 500+ connectors and  
500+ sockets for PCB mounting and using a modern, micro-sized form  
factor would seem to be far better.  Much higher integrity  
connections and one can perform any pair twisting or coax run or any  
other schema for the interlinks.  Even a set of sata pairs (plug and  
socket) would seem better as they can be stacked on a PCB layout one  
right next to the next one.  Ten sata connector sockets would fit on  
an interface pcb in a couple square inches, whereas those old phone  
interlink jacks and plugs are simply far to big for such a huge  
sensor unit count.

  Very similar to the old audio interconnect cables on the first CD  
players for PC installation.  They are like 3 or 4 wire inline  
miniature connector heads.  They were white and they had god  
retention in their deisgn.

 Google images or just google

jst sh jumper

<https://www.google.com/search?q=jst+sh+jumper

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
Jeff Liebermann wrote...
Quoted text here. Click to load it

 Yes, all that and much much more.  60 sensors so far,
 and now adding 12 more, including gas sensors.  E.g.,
 we count every single bee trip in/out of hive, see up
 to 170,000 trips (not under 10,000).  Including the
 back door.  Two microphone sensor channels.  Also
 getting sugar-water level.  LoRa real-time reporting.
 As a scientific research tool, have learned a lot, I
 hope, but not yet sure of value to experienced beehive
 operators.  Had 6 systems out last season, will deploy
 15 more this season.


--  
 Thanks,
    - Win

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
On a sunny day (12 May 2019 18:09:31 -0700) it happened Winfield Hill

Quoted text here. Click to load it

I wonder if this sort of technology
 https://www.fastcompany.com/3059127/what-happened-to-the-mosquito-zapping-laser-that-was-going-to-stop-malaria
without the killing green laser part,
can be used to track individual Bs.
Each B having its own wing flapping pattern, some AI learning software..
Maybe ask that Microsoft inventer?

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it

Their own wing flapping pattern?

  No, they are all the same and their wing flapping 'patterns' are too.

  The software counts the actual bees.  It does not discriminated down  
to wing motion...   And never will.

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
snipped-for-privacy@decadence.org wrote...
Quoted text here. Click to load it

 We count every bee trip going in or out of the hive.
 This is a little different from measuring bee flights.
 Standing in front of the hive, watching for 15 minutes,
 say in the morning, virtually all of the IN/OUT trips
 are associated with a flight.  The bees seem to know
 exactly what they're doing, and concentrate on that.

 And yet we count up to 20x as many trips as they
 measure flights.  OK, it is true that in the late
 afternoon, I've observed a lot of IN/OUT activity
 not associated with bee flights.  They seem unsure
 at that point in time, and may even make a wall of
 bees on the front of the hive.  But this time-frame
 is not when we get most trips counted.  It appears
 that their camera and software must miss seeing a
 lot of flights.


--  
 Thanks,
    - Win

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it


  Paralax error goes up during large exodus/ingress periods.

  I used to make pharma tablet counters and they had 16 channels for  
the pills to fall through and yet would still fail if two went  
through together past the optical sensor in a channel.

  Most pharmacies I see these days have gone back to hand counting.  
much cheaper than the expensive tablet counters.

  Reduce camera resolution and increase frame rate.  Somewhere there  
is a happy medium where optimal counting is the result.

Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?
On Monday, May 13, 2019 at 6:58:34 AM UTC-4, snipped-for-privacy@decadence.org wrote:
Quoted text here. Click to load it

He's speculating they can learn the sound of each individual bee like they can distinguish the unique sounds of propellers on submarines.  Who knows, maybe... some day.  Do Bees do crazy Ivans?  

--  

  Rick C.

  - Get 5,000 miles of free Supercharging
We've slightly trimmed the long signature. Click to see the full one.
Re: RJ45, RJ12, RJ14 cables, straight-through or crossover?

Quoted text here. Click to load it

  Fat chance.  The term 'din' comes to mind.

Quoted text here. Click to load it

  No, and neither do Russian sub commanders.

  Back out and go to high speed camera and track them in and out  
farther than the current window.  IOW increase the resolution and  
frame rate of the current optical system (I know it takes a lot of  
fast storage).  Look at other factors later on.  Polish the shine on  
what you already have.

Site Timeline