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RS485


Sci.Electronics.Design is a worldwide Usenet news group that is used to discuss various aspects of Electronic Circuit Design.

We found 23 threads matching "rs485"

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The most relevant threads are listed first

RS485 resistors

Marco Trapanese - 2008-01-11 05:14:00
Hello, I'm talking about the usual RS485 front-end: MAX485, series resistors (if any), pull-up/pull-down and termination resistor. The system I'm working on has two RS485 transceiver at both ends of a twisted-pair cable. Its length is between 250 m and 500 m. I'm wondering how to dime...RS485 resistors

RS485: testing loopback

Ajab - 2007-12-21 03:27:00
I am using a rs232 to wire rs485 converter. I have shorted TX+ with RX + and TX- with RX- for 2-wire configuuration. A 120R termination resistor is connected between TX+ and TX-. I am using it in half-duplex configuration. Is it possible to test loopback. Because in half-duplex either tx or rx ...RS485: testing loopback

RS485 Timeout

2008-01-09 15:35:00
Hi, I am writing an application for a RS485 network. Basically, a client server program. So when server sends command out, the client who receive it send some data back. My question is that how long the timeout should be for the server? How long should the server wait before report a time ou...RS485 Timeout

RS485/422 Isolated Network

Babak - 2008-02-22 10:01:00
Hello All, Could you validate the following assumption(s) on isolated network implementation 1) An isolated RS485/422 Comport can connect to the none- isolated network. 2) Having more than one isolated comport will require a separate isolated power source for each of the isolat...RS485/422 Isolated Network

help needed for rs485 !!!!

michael nikolaou - 2009-04-05 03:11:00
Hi to newsgroup I want to implement an RS485 interface to an microcontroller with the purpose of creating a network of 10 controllers located about 200 mt from a pc . Although everything is clear regarding the interface what is obscure is the protection needed. I've seen schemes using a 100...help needed for rs485 !!!!

RS485 grounding part 2

mkr5000 - 2008-09-21 10:03:00
I've read some material (a Jan Axelson article), that further confuses me on this matter of proper RS485 grounding for the shield that surrounds our twisted pair of data. Like I say, I have always just grounded just one end to a good EARTH ground, either my transmitter or receiver, depending o...RS485 grounding part 2

SBC+Display

Dirk Bruere at NeoPax - 2009-02-19 07:58:00
Looking for a very basic SBC with RS485, IR receiver and capable (or with) a multiline back lit color text display. I don't need much processing power - it just needs to display text and pick up IR. Anyone make something like that? Dirk ...SBC+Display

SPDIF to AES/EBU

Dirk Bruere at NeoPax - 2010-03-02 16:49:00
Looking for a reliable circuit for the level conversion from SPDIF to TTL. I then intend to feed it to an RS485 driver and into a transformer for transmission via CAT5e -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.theconsensus.org/ - A UK political party http:/...SPDIF to AES/EBU

Re: Why do we have cross-over cables.

Jasen Betts - 2009-03-23 21:42:00
On 2009-03-23, Jeroen Belleman wrote: > > No it doesn't. It entirely misses the point, which is why there is a > > distinction betwen DCE and DTE. > > It would surely be much nicer if equipment at both ends of the link used > just a single pair to communicate in both directions, full...Re: Why do we have cross-over cables.

Re: ethernet over a single pair of wires?

mook Johnson - 2008-02-05 21:14:00
> > I can't see why it shouldn't work. I've certainly managed to get 100Mb > half- duplex operation by accident when debugging Ethernet (KS8993/5) > designs. I expect all switches do autonegotiation now. But if you're > worried, it's easy to try out- just take an ordinary Windows network...Re: ethernet over a single pair of wires?

Re: How to interface a microcontroller to fibre optic?

Oliver Faust - 2009-03-31 03:57:00
Dear Graham, Thank you for your response. > 8051 family devices have a UART that in one mode will run at 1 Mbps with > as 12MHZ clock crystal. This is one of my problems, from what I have read a simple UART can't be used for fiber optic transmission. As far as I know there is no optical tran...Re: How to interface a microcontroller to fibre optic?

MOS optocouplers...

Arie - 2008-04-28 13:55:00
A rather strange effect puzzled us today... We use a MOS optocoupler to switch a RS485 terminator. The production test sometimes failed and indicated the terminator was on while it should be off. When probing the drive to the optocoupler, it sometimes switched on or off, depending on when or w...MOS optocouplers...

Re: Any gotchas using CAN bus?

Robert Adsett - 2008-04-04 10:51:00
In article , Mook Johnson says... > I have a project where CAN bus is being proposed for connecting several > custom instruments together on a 200Ft long single twisted pair. > > I am no serial protocol expert but when CAN was brought up in two seperate > other venues, it got shot d...Re: Any gotchas using CAN bus?

Re: Uses for old TVs?

Martin Riddle - 2009-06-23 20:05:00
"Jim Thompson" wrote in message news:tg6245hquf5k6550qlnrpdtl4g6tl62qfi@4ax.com... > On Tue, 23 Jun 2009 11:02:38 -0700, "Paul Hovnanian P.E." > wrote: > > > Too_Many_Tools wrote: > > > > > With the advent of digital OTA, lots of good analog televisions are > > > being surpl...Re: Uses for old TVs?

Re: Driving 0.5km CAT5

David L. Jones - 2010-01-08 07:17:00
pimpom wrote: > Prelim: If anyone remembers me from previous posts, please note > that constraints imposed by my location dictate that I use, as > far as possible, only long-established standard components in my > projects. > > I want to send two independent unidirectional pulsed signals...Re: Driving 0.5km CAT5

Re: Tunable Bandpass Filter

ChrisQ - 2009-11-18 17:30:00
Joel Koltner wrote: > "ChrisQ" wrote in message > news:eCRMm.661$mC4.267@newsfe22.ams2... > > Haven't done much radio for years. > > So what kind of things do you work on these days? Have been freelance since the mid 1970's. Now getting a bit wrinkly, but manage to stay in work m...Re: Tunable Bandpass Filter

Re: Tunable Bandpass Filter

JosephKK - 2009-11-20 07:39:00
On Wed, 18 Nov 2009 22:30:33 +0000, ChrisQ wrote: > Joel Koltner wrote: > > "ChrisQ" wrote in message=20 > > news:eCRMm.661$mC4.267@newsfe22.ams2... > > > Haven't done much radio for years. > > =20 > > So what kind of things do you work on these days? > > Have been freelance sin...Re: Tunable Bandpass Filter

Possible Latchup problem with RS485 transciever

logjam - 2008-10-11 16:06:00
I have a project where the input of an RS-485 receiver can have voltage on it before the main power supply comes on. My project has worked well in the past when my cable's bus voltage was 12v and I used some 12v to 5vDC Astrodyne DC-DC converters. I am now using a cable bus voltage of 48vDC ...Possible Latchup problem with RS485 transciever

Re: my lab

Martin Brown - 2009-10-12 05:11:00
krw wrote: > On Sat, 10 Oct 2009 13:57:47 +0100, Martin Brown > wrote: > > > krw wrote: > > > On Fri, 9 Oct 2009 17:42:58 -0700 (PDT), a7yvm109gf5d1@netzero.com > > > wrote: > > > > > > > On Oct 9, 7:09 pm, Joerg wrote: > > > > > > > > > GPIB is terrible. The topper happen...Re: my lab

Re: Location of phone wall sockets

Ross Herbert - 2009-04-05 23:26:00
On Sat, 04 Apr 2009 17:20:13 +0100, Don wrote: :On Sat 04-Apr-2009 09:41, David Woolley wrote: :> Don wrote: :> > :> > I am moving the telephone wall socket in my study because I'm :> > often checking out some extra phone device and need better :> > access than a single socket at...Re: Location of phone wall sockets

Re: my lab

krw - 2009-10-12 22:59:00
On Mon, 12 Oct 2009 21:01:29 -0400, Phil Hobbs wrote: > krw wrote: > > On Mon, 12 Oct 2009 10:11:05 +0100, Martin Brown > > wrote: > > > > > krw wrote: > > > > On Sat, 10 Oct 2009 13:57:47 +0100, Martin Brown > > > > wrote: > > > > > > > > > krw wrote: > > > > > > On ...Re: my lab

Re: Minimum frequency on Cat.5

2008-12-17 17:55:00
I hate interleaving stuff but just have done :) va...@silvtrc.org wrote: > john@jjdesigns.fsnet.co.uk wrote: > > The 1000's of metres of CAT5 I've measured looks perfectly 'normal' > > from DC to way beyond 100MHz. (as any old bits of wire should). At low > > frequencies you only need ...Re: Minimum frequency on Cat.5

Re: ucontrollers (AVR/ATMega) and radio transceiver modules

Tim Watts - 2010-01-25 07:52:00
On Mon, 25 Jan 2010 03:17:50 -0800, John Walliker wibbled: > On 25 Jan, 10:22, Tim Watts wrote: I fancy having a > > play with some radio datalinks (with a view to home automation) - but > > there seem to be a million modules and a fair number of > > frequencies and standards. I'm j...Re: ucontrollers (AVR/ATMega) and radio transceiver modules