Sign in
Search Comp.Arch.Embedded
embedded by Keywords
68HC11 | 68HC12 | 8051 | 8052 | ARM | ARM7 | Asic | AT91 | AT91RM9200 | Atmel | AVR | AVRStudio | Bootloader | CFP | CompactFlash | Cygnal | Cypress | Dataflash | DSP | eCos | EEPROM | Embedded Linux | Emulator | Endian | Ethernet | Firewire | FPGA | Freescale | GCC | GNUARM | GSM | H8 | HDLC | I2C | Infineon | Interrupts | Java | JTAG | LCD | LED | LPC2000 | MCU | Microchip | MMC | MPLAB | MSP430 | PC104 | PCB | PCI | PCMCIA | PowerPC | Rabbit | RS232 | RS485 | RTOS | SBC | SDRAM | Sensor | SPI | STK500 | UART | UML | USART | USB | Verilog | VHDL | VxWorks | Xilinx
Discussion Groups
RS485
Comp.Arch.Embedded is a worldwide Usenet news group that is used to discuss various aspects of Embedded Systems development.
We found 120 threads matching "rs485"
You are looking at page 1 of 3.
The most relevant threads are listed first
WTD Addressable RS485 to RS232 Serial converters
Joseph Goldburg - 07:49 23-05-04
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 - 23:14 10-02-04
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 - 05:46 29-11-05
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 - 14:49 09-06-06
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
...Two quick RS-485 questions
Lewin A.R.W. Edwards - 13:31 29-04-04
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 - 06:02 25-01-06
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
03:52 12-10-05
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 - 05:31 17-11-07
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 - 18:32 23-01-04
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 - 22:07 16-11-07
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 - 20:35 04-01-05
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...RS485 Networking
suparoo - 16:28 11-05-08
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 - 01:03 12-03-04
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
11:06 15-12-07
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 - 22:23 09-01-05
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 - 21:54 04-04-07
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 - 13:11 19-09-04
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 - 17:46 22-09-05
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?
...[RS485] can't perform handshake.
SarAVR - 21:23 10-07-07
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
11:16 15-12-07
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
05:12 02-01-07
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 - 14:21 10-01-05
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 - 15:46 14-11-04
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 - 16:08 24-02-06
Does it exists a bridge from ethernet to rs485 9bit protocol (for 8051, avr
and so on .. )??
thanks
...Different devices on RS485 line?
ElderUberGeek - 03:17 16-03-07
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 - 00:03 02-04-04
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 - 18:24 07-02-08
"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?
03:19 06-07-07
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...Re: RS485: testing loopback
TT_Man - 08:09 21-12-07
"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 - 08:07 28-08-06
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 - 23:32 06-06-04
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...Anyone using the Lantronix XPort?
Neil Cherry - 23:51 13-01-04
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...8051 serial problems
Edo Reshef - 11:33 21-04-04
Hi,
I have an 8051 controller that communicates over RS485 to other 8051
controller. The communication is half-duplex at baud of 57600, and it
works great. So far so good.
Lately, I'm trying to make the 8051 device talk with a PC, since it is
57600 and I have RS232 RS485 converter this shoul...[PIC] New electronic projects site (Schematics only at the moment)
William at MyBlueRoom - 23:42 26-02-06
Here's my list of current PIC projects on my web site
www.myblueroom.com, currently only the schematics are posted but I will
post descriptions and source code asap.
Armadillo: (iButton Door Lock) Preview, Incomplete
PIC 16F87 or 16F628A based iButton, keypad and remote controlled door
loc...Looking for 9 bit RS485 solutions
10:30 17-10-07
Hi,
We have various products that interface to Point Of Sale terminals
(a.k.a. cash registers). These use IBM's 4683 protocol which is a 9
bit (address bit) RS485 bus. We'd like to build some test tools so we
don't have to always use a POS terminal.
Anyone know of any 9bit 485 adapters, c...Re: Looking USB to RS-232 + RS-422/485 Module ?
Dac - 19:32 11-08-06
"Anton Erasmus" wrote in message
news:4h9pd25gmobmopos2ivgbv98vuin8iufn7@4ax.com...
> Hi,
>
> I need 2 simple Asyncronous serial ports on a laptop without any
> serial ports. I have found many USB to RS-232 and a few USB to
> RS-422/485 modules, but have not able to find a reasonabl...mscomm in vc++ - parity error
Jim - 13:59 07-12-06
Hi,
I'm writing some logging software for an embedded alarm panel design that
uses an RS485 bus and proprietary protocol.
I've attached the obligatory RS485 -> RS232 converter and connected to a
free serial port on my PC. All good so far!
Now, the alarm panel deliberately causes a parity...Re: Implementing communication over RS-485
mehulag - 12:50 09-09-06
>
> Meindert Sprang wrote:
> > "Mike Silva" wrote in message
> > news:1157811417.323232.68980@b28g2000cwb.googlegroups.com...
> > > Yes, ModBus is a workable solution.
> >
> > You must be joking.
>
> No, my jokes are funnier.
>
> > A protocol that relies on inter-frame times fo...Serial To Ethernet Converter
QwertyBel - 09:01 25-10-06
I need to remote RS232/RS485 signal over ethernet infrastructured
network,
which kind of device do you suggest me?? thanks a lot
Bel
...Serial to Ethernet Device Servers on Linux
01:47 23-10-06
Hello there!
I am new to low level programing. I have a Moxa 5232 Device server. I
have a rs485 device that I like to be able to access from a Linux
computer. It is a 2 wire 1/2 duplex rs485 enabled device.
After installing the Moxa drivers I have a "/dev/ttyr00 & /devttyr01"
devices/ports ...