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RS485
Comp.Arch.Embedded is a worldwide Usenet news group that is used to discuss various aspects of Embedded Systems development.
We found 155 threads matching "rs485"
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The most relevant threads are listed first
WTD Addressable RS485 to RS232 Serial converters
Joseph Goldburg - 2004-05-23 07:49:00
Hi All,
I am looking for RS232 to RS485 serial converters.
Requirements
----------------------
The converter should have a small buffer 20 bytes to 1k bytes.
The converter should have an RS485 address.
Thus the converter listens to the RS485 bus traffic.... if it spots it's
address th...
RS232 or USB to RS485
QBA - 2004-02-10 23:14:00
I need RS232 to RS485 converter or USB to RS485 converter, are there vendors
out there you recommend for these converters? More specifically, RS485 I am
using is 2-wire (ground, don't need 4-wire version) at 19200 baudrate.
...Monitoring RS485
Daniele - 2005-11-29 05:46:00
Hi all,
i need an informatio about rs485:
I need to watch netwrok trafic from my device and another device that
use rs485 to comunicate. Is possible to connect in parallel mode
another peripherical (like a pc via rs232) to trace all the message
that is exchange from two device?
Thank...RS485
jjvijay - 2006-06-09 14:49:00
As we know In RS485 we can connect 32 nodes.,I have one doubt in RS485
Standard we can use upto 4000ft (distance)...will this length is between 2
nodes or we have to connect 32 nodes within this lenght(distance)...I am
waiting for the valuable solution....
urs
vijay
...Re: Need ARM with 485, digital counters and analog I/O
Frank Buss - 2009-08-17 14:39:00
tmunro wrote:
> I am looking for a new embedded computer that has an ARM processor or
> equivalent, 64MB of Flash, 128MB ram, two 485 ports, at least 2 digital
> counters, at least 8 analog 4-20ma connections and support for micro SD
> card.
>
> I have played with the TS7200 - nice bu...Two quick RS-485 questions
Lewin A.R.W. Edwards - 2004-04-29 13:31:00
Hi all,
I have to implement a very simple multidrop RS485 application,
carrying slow 2400bps or even 1200bps data from a PC to a half-dozen
devices about 300 feet away. The data flow is unidirectional; the
devices don't talk back. Low cost is a significant factor in this. I
plan to stick an R...RS-485 Troubleshooting
RahulS - 2006-01-25 06:02:00
Hi,
I am using Rabbit development board which has separate ports for RS232
and Rs485. Right now i am using a single port both as RS232 as well as
RS485.
The port works fine for RS232 signals but for RS485 signals, the
differential output is not proper.I think there is some problem with
the dif...Re: Bus speeds on Open Collector Output
2005-10-12 03:52:00
Differential will give you better noise immunity.
Check out the traditional way of doing this: RS485.
Intersil have a number of very high speed RS485 drivers. ISL8487,
ISL8488 and ISL8488 can all do 5 Mbits/sec. Then there's the ISL83491
at 10 Mbits/sec and even a ISL81486 capable of a blister...8051 and RS485 how to
rajeshbij@gmail.com - 2007-11-17 05:31:00
I want to communicate with 10-15 micro controllers from the host micro
controller. Each node(independent micro controller) may be around 500
meters distant from the host. The no. of micro controllers and the
distance may increase. I feel I should use RS485.
Anybody, please let me know what sho...RS485 with +-15V common mode
Ralph Malph - 2004-01-23 18:32:00
Boy, I thought it was tough finding an I2C port expander chip that fit
all my requirements. I am looking for an RS485 tranceiver that I can
use along with an RS232 chip to allow either protocol through the same
pins. But I can't find an acceptable chip anywhere.
This was discussed a few we...rs485 question
JY Kim - 2007-11-16 22:07:00
Hello.
I am software enginer and working with board with rs485
rs485 transceiver is 3.3V ST3485E and is connected with PLC.
When I send data from my board to PLC, voltage level is 3.3V but PLC
send 5V data.
PLC recognize 3.3V input data in 1200bps but not 9600 bps. when PLC
recognize 1200bps...RS485 A/B line reversal in extant devices
Steve at fivetrees - 2005-01-04 20:35:00
Every time I design a product with an RS485 interface, I wind up going over
the same old ground in disbelief - and coming up with the same answer. The
A/B line-naming convention is reversed when comparing extant devices (e.g.
the venerable SN75176B, or the transceiver product line from Maxim) wit...2 wire rs485
Vasilis - 2009-02-10 12:15:00
Hello list,
I'm having problems talking to a 2 wire rs485 device.
This is my following configuration:
- embedded pc104 board AAEON PFM-530I
- programmable electricity meter with rs485 interface for
communication.
Now, setting a few jumpers on the board toggles an rs485 port on
ttyS1.
M...Any experiences running 460 kbaud RS485?
Mike Silva - 2009-05-28 15:27:00
We're looking at a design that would have 1 RS485 master and 2 slaves,
with a maximum cable length of 50 meters (25m is more likely), and
we'd need to run a data rate of 460 kbaud. Since the RS485 spec talks
about data rates of 10 Mbaud and cable lengths of 1200 meters (not at
the same time) it...RS485 Networking
suparoo - 2008-05-11 16:28:00
Hi, would anyone be able to point me in the right direction for RS485
network training? Cant find anything online and need to rectify an
intermittent fault on a relativly basic 485 over mm fibre setup.
Any info on testing would be most welcomed, but please understand my
existing knowledge is limite...RS485 chips and differential voltage
Dennis Clark - 2004-03-12 01:03:00
I've been reading up on RS485 drivers like the LTC485, 75176B and others.
They look too simple in pin count to supply the + and - voltages needed
for differential drives. Are there some chips that supply the +/- voltages
that other chips simple scavange and use? Or do these chips I note actua...RS485 half duplex and full duplex questions
2007-12-15 11:06:00
regards:
by the way could I ask a question,could I simply use the "RTS line" to
control
RS485 half duplex mode?
and I ask a question.
and when I am using RS485 FULL duplex (RS422 mode),Do I need any
control
lines like "RTS","CTS"?
any positive suggestion is welcome.
best regards to...Cheap Processors with Fast USARTs for RS485?
Christopher Graham - 2005-01-09 22:23:00
I want to implement low cost rs485-connected data collection nodes, and need
to choose a microcontroller for them that will support baud rates of more
than say 400 kbps, preferably up to 1 mbps. I know there are some
PIC18Fxxxx's that have an "Advanced UART" that are claimed do this. Other
...Lightening protection ?
Alex Gibson - 2007-04-04 21:54:00
Can someone suggest the most reliable way for lightening protecting a three
wire rs485 setup.
Boards on the structure(steel) will be connected via 6 or 8 core twisted
shielded.
Three wires for rs485,then +24VDC , pwr gnd and a few spare.
Option for separate power cable if required.
I wa...Is termination needed for short and slow RS485?
mrsoft99 - 2004-09-19 13:11:00
We are running some led billboard displays using a multi-drop 2-wire
RS485 network.
The cable length is 50 feet; the baud rate is 2400 baud.
Are RS485 terminators really needed for this? I know they are needed
for 'long' cables and 'fast' baud rates, but does 50 feet at 2400 baud
qualify for...RS485 CSMA/CD protocol
therion - 2005-09-22 17:46:00
Hi, I would need to implement an CSMA/CD L1 protocol code for RS485 in my
new AVR project for home automation.
Any link, hint or help for the similar source code?
...PPP over RS485 - Speed
vijaygs - 2008-10-27 07:45:00
Hi,
I am working on increasing the speed of data transfer between two
electronic modules(each running OSE operating system)using PPP(supported by
OSE)over RS485. However be the baudrate i configure the maximum speed i get
is 8KiloBits per second. Even if the baud rate has been changed to
38400k...[RS485] can't perform handshake.
SarAVR - 2007-07-10 21:23:00
Hello all.
I am just a novice who wants to use ATmega8535 as a means to control RS485
communication devices.
Communication type to implement is full duplex and I used two MAX485
transceiver ICs per one board, one for transmitting and the other for
receiving.
As I burned ATmega microcontroll...RS485 half duplex and full duplex question
2007-12-15 11:16:00
regards:
How could I test RS485(half duplex) or RS422(full duplex)
any positive suggestion is welcome.
best regards to you all
mike-smith
...Lantronix UDS1100 in multidrop RS485 application
2007-01-02 05:12:00
Hi,
I've got an application that requires a number of environmental controllers
be connected on an RS485 2 wire half duplex multidrop bus. I was looking
at the Lantronix UDS1100 device servers (or even the older UDS100 / UDS10 )
to let me use the customers LAN so as to save wiring costs.
I ...UARTS that generate an interrupt if bit 9 = 1 ? (for RS485 protocol)
Chris Graham - 2005-01-10 14:21:00
I am designing an RS485 network, and was reading a Circuit Cellar article by
Ambekar that describes a protocol that uses 9 bit characters, where a
non-zero 9th bit indicates that the character is a control character.
The described network used Intel MCS51 UART that can apparently be set to
...RS485, multidrop protocol
Ian McCrum MI5AFL - 2004-11-14 15:46:00
I wonder if there is documentation on standard RS485 protocols
anywhere for download?
I have homebrewed a couple of these in the past but is there a
standard way of doing this?
I am interested in using the serial port of a linux machine, with
RS485 line drivers/receivers and probably RTS co...ETHERNET to 9bit Rs485 bridge
MikeRam - 2006-02-24 16:08:00
Does it exists a bridge from ethernet to rs485 9bit protocol (for 8051, avr
and so on .. )??
thanks
...Different devices on RS485 line?
ElderUberGeek - 2007-03-16 03:17:00
As RS485 is multi-drop, one would assume that you can hang multiple
devices on the same line (meaning different devices of different
makes, like say two controllers from two different manufacturers). I
have two questions:
1. Is this at all possible, or should all devices on the 485 line be
th...bombproof RS485 chips?
Dennis Clark - 2004-04-02 00:03:00
Hi all,
I'm working a project where I've got several RS485 nodes cabled together
in about as hostile environment as I can imagine. High powered vacuum
pumps, high current stepper motors, high static discharge possibilities,
etc. Can anyone suggest an 8 pin part that is REALLY bombproof to ...Re: RS 485 on advantech PCM-4153 board
Steve at fivetrees - 2008-02-07 18:24:00
"muktabh" wrote in message
news:cdGdnb0bHvpf9zbanZ2dnUVZ_sGvnZ2d@giganews.com...
> Hi,
> I have an advantech PCM-4153 board with 4 com ports. The user guide
> says
> port 2 can be configured as a RS485 port. I have a few doubts.
> I am using linux on this board. Will I need special d...RS485 is too expansive: any replacement?
2007-07-06 03:19:00
Hi,
I'm called to design a multi drop network where the nodes communicate
using 2 wires.
The distance from 2 nodes is maximum 20 meters. The wires will run
along the mains (220 V).
I requested a quotation for the following part:
MAX3483ECSA (3 Volt, ESD protetecte...Problem Reading Serial Port (RS485)
andrea1984 - 2009-05-13 09:53:00
Hi all,
I've a FOX Board (Linux Embedded) with RS485 port, and a Power Counter
(RS485 too) that work at 9600E1.
With a USB to RS485 cable and windows i can successfully communicate with
the Counter, writing a simple c# application. The rs485 linux board work
too (with others devices).
I can't r...Re: RS485: testing loopback
TT_Man - 2007-12-21 08:09:00
"Ajab" wrote in message
news:a14a9be3-7bb0-48cc-ae64-6bb9bdb30c30@t1g2000pra.googlegroups.com...
> 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 ...Ask RS485 Trouble ?
TR6 - 2006-08-28 08:07:00
Hi,
I have built RS485 communication for 11 AT89S51 microcontrollers. Consist
1 master and 10 slave nodes. I use SN75176BP for RS485 driver. All
microcontrollers connected using UTP Cat-5 Cables in a bus :
Safe bias resistor-SL1-SL2-SL3-SL4-SL5-SL6-MA-SL7-SL8-SL9-SL10-resistor
terminator.
From SL...Does RS422/RS485 work on Advantech PCM-5820?
Lewin A.R.W. Edwards - 2004-06-06 23:32:00
I just received an unpleasant surprise when trying to use differential
serial on the Advantech PCM-5820. The system has jumpers for the
second serial port; RS232, RS422 or RS485. In either RS422 or RS485
mode, I see no activity at all on the TxD+/- pins.
My software is asserting DTR and RTS, s...RS458 Cabling
bfranklin825 - 2009-06-12 13:19:00
I have a piece of equipment that uses RS485 with RJ45 jacks and I was
wondering if I needed special cabling with only 4 of the wires phyically
connected in the jack or could I just use regular CAT5 Ethernet cabling
with all eight wires present? The specs that I have for the cable only list
4 wires, ...Anyone using the Lantronix XPort?
Neil Cherry - 2004-01-13 23:51:00
I just received the Lantronix XPort and it works as advertised but I
am very disappointed with the dev kit as it lacks anything to develop
custom software for the the XPort processor (no libraries, no
examples). Also I uses .cob files but gives no details as to read
them (I suspect that they ar...Re: 2 wire rs485
Oliver Betz - 2009-02-20 03:46:00
nemo wrote:
[...]
> > > And the current loop is usually no bus with several devices since the
> > > receiver takes all the _energy_ of the signal.
> >
> > In current loop systems with more than two stations, you simply put
> > them in series. All inactive stations are in the idle (mar...How do i interface with the processor and acheive 10 Mbps?
2009-01-22 02:15:00
I found that many RS485 transceivers can transmit data at the rate of
10 Mbps.
My application requires that speed to communicate for a short distance
(2 feet or 0.5 metres or so).
Processors have UART which can transmit at 115kbps and not more.
How do i acheive 10Mbps when the normal 32 bit p...