Questions tagged [rs422]

RS-422 is a point-to-point serial communication bus using differential signalling to achieve high data rates.

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8k views

What does 232 signify in the RS232 standard?

"RS" in communication standards RS232 and RS485 stands for "Recommended Standard". But what information does "232" or "422" or "485" convey in the name? What naming convention is used for numbers ...
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4answers
7k views

What can I do to decrease the latency from these serial ports which are attached to a PC via a Serial to USB adapter?

I think I have accidentally discovered a need in my life for embedded systems. Which is great! And kind of scary. And I need help. Background: I got hired to build a GUI application which takes scans ...
4
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1answer
4k views

Long distance Arduino sensor network - 1Wire protocol or RS422?

I have some sensors from each of which I need to - read a voltage - be able to switch them on. (They are powered by AC 220V power supply). Distance to be covered is some 40 meters. I don't want to ...
4
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2answers
298 views

RS-485 best isolation practices

There are several isolated solutions on the market such as ISO1176DW. These ICs usually pretty big, expensive and consuming. However I could use non isolated transceiver with isolated power supply ...
4
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1answer
4k views

How do I choose an optocoupler for (19200 baud) serial communication between Arduino and RS422 transceiver?

I wish to read data from a Fronius solar inverter via the Fronius RS-422 Com Card option (part# 4,240,001). 1000 meter cabling length The Fronius communication uses a 5-wire RS 422 interface (`RX-`, ...
3
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2answers
39k views

Standard pinout for RS-422?

I am making a custom connector that will carry several signals to a test board including RS-422 RX+/RX- and TX+/TX-. The strange thing is that I didn't find a standard pinout for the DB9 connector ...
3
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2answers
1k views

Using RS-485 receiver with RS-422 signals

I have a controller that has a RS-422 output. Can I use it to only send data to another device that has RS-485?
3
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1answer
356 views

Opto-coupled EIA-422 receiver (understanding suggested circuits)

I am looking at a standard for communication of marine electronics (NMEA). The standard is electrically essentially EIA-422 but it prescribes opto-coupled differential receiver pins without connection ...
2
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2answers
4k views

Different RS485 Full-Duplex with RS422 [closed]

Are RS485 Full-Duplex interface same with RS422 interface?
2
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3answers
1k views

What effect does using a termination resistor that is larger than the characteristic impedance of the transmission line?

I have seen that when terminating an RS422 point-to-point connection, you should terminate the signals with a parallel resistor that matches the characteristic impedance of the transmission line. Most ...
2
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1answer
348 views

RS-422 for pseudo-multipoint bus topology?

I have been trying to get a definitive answer on the possibility to use RS-422 for connecting one master and several slaves in a pseudo-multipoint/bus fashion, with slaves being able to send some data ...
2
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2answers
1k views

Serial data received in wrong bits

I have an RS422 interface set up between an Arduino and a custom-built device. The device is set to transmit a 16-bit header, followed by 66 bytes of data, at a baudrate of 460,800 and at 200Hz. This ...
2
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1answer
883 views

Alternative to high Watt resistor terminating resistor

In the following circuit a 120 ohm termination resistor is placed across the Rx+ and Rx- data lines connected to a RS485/422 transceiver. The transceiver is protected up +/- 60V. simulate this ...
2
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1answer
2k views

RS-422 distance sensor with arduino

I need to make a converter to go from RS422 full duplex to my Arduino. I have found lots of different chips which I think can do this, but am slightly confused by the terminology. The RS422 device is ...
2
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1answer
114 views

How to send Sensor Output signlas to Long distnaces?

In want to interface Incremental encoder sensor output to Microcontroller which is 10 meters away from the sensor. Specifications: Sensor Output : Square wave 0V to 5V , 100KHz frequency. ...
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3answers
9k views

Can I an RS422 interface to Arduino's serial pins?

I have a custom-designed circuit that communicates to and from the external world through an RS422 interface. I wish to communicate with it with an Arduino, preferably UNO. The RS422, much like the ...
1
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1answer
192 views

13Bit Encoder interface for microcontroller

I am running out of time and seeking a proper solution. What I am willing to achive is getting the position of the encoder / motor shaft. To keep track of the movement. (Currently I am running 10 ...
1
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2answers
612 views

How can we sure about common mode voltage for RS422/RS485 without ground connection?

RS422 and RS485 standards specify different common mode voltage limits. In some application notes, I see that ground connection between two node is somehow optional. Suppose that two nodes are ...
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2answers
2k views

How would I make an Arduino Due recieve RS-232/422 signals?

Background on this question is here: What can I do to decrease the latency from these serial ports which are attached to a PC via a Serial to USB adapter? I'm looking at purchasing an Arduino Due to ...
1
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1answer
79 views

RS422 and RS485; full-duplex or half-duplex?

I have extensively used RS232 transceivers in many projects and have fairly good understanding of UART communication using RS232 transceivers. MAX232 and MAX3232. Now I have to build my understanding ...
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2answers
217 views

What could be the reason for this RS422 wiring?

I usually follow the following wiring scheme for RS422 wiring: As seen above R+ to T+; R- to T-; T+ to R+ and T- to R-. So for each point to point wire R and T coupled but the signes are same i.e + ...
1
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1answer
502 views

RS422 to uart interfacing

I am trying to interface an RS422 to the UART on my MCU. Now, RS422 is differential. So, I understand that I need to have a differential to single ended converter IC. This is followed by a voltage ...
1
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1answer
112 views

Do I need an impedance controlled connector for RS422?

I've never implemented RS422 before (crazy right?). Since the impedance of the line is controlled to 120Ω do I need an impedance controlled connector for that? If anyone has implemented RS422 which ...
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2answers
431 views

Are RS232 to RS422 converters reversible?

I'm trying to get a MCU with a db9 female serial out port (using RS422 protocol) to communicate with a CY8CKIT-050 PSoC® 5LP Development Kit (running a microcontroller). The development board comes ...
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1answer
179 views

Interfacing an RS422 driver and receiver

I am trying to interface an RS422 driver and a receiver. What are the important voltage parameters I need to understand when selecting the relevant chips. From what I understand the most important is ...
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1answer
561 views

RS422 basics understanding

I am understanding the basics of RS422. Now, consider a driver (RS422) connected to a reciever. Now, we have a termination resistor of about 100Ohms or 120Ohms. Now, imagine the driver sends out Voc ...
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0answers
351 views

Is the ground necessary with an opto-isolated RS422 signal

I have 8 opto-isolated RS422 ports to install. All of them are coming from a single PC card. It provides the opto-isolation for every RS422 port. Every signal is opto-isolated from the PC ground and ...
0
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2answers
47 views

RS422 Receiver Not Reporting Errors When Too Few Stop Bits

I am interfacing with a device (the transmitter) which configures its serial settings to 8 data bits, no parity, 1 stop bit at a baud rate of 115200. These are known values and fixed values I can't ...
0
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2answers
7k views

STM32 RS485 connection

I want to interface stm32f0 with rs422 (half duplex and full duplex). What I'm not getting how to connect RE and DE signals to rs 232. From UART I'll be having RX, TX, VCC and GND pins which i need to ...
0
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1answer
73 views

RS422/RS485 data input series resistor

I am using an RS422/RS485 driver to send Arduino 5V logic data over longer distances. I use the SN75174 driver for this purpose. In order to avoid ringing, I am not sure if I have to connect a series ...
0
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3answers
74 views

RS422 Full-Duplex Cable Shielding

I need to interface two PCBs via RS422 (250kbps) in full-duplex mode (4-wire, 2-twisted pairs 100ft cable). This system will operate in a noisy (CNC) industrial environment, ie, industrial controls ...
0
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1answer
57 views

Testing an Encoder's Accuracy

I'm using a high-frequency (1024PPR) RS-422 encoder, connected to a differential line receiver, and in turn, a quadrature encoder interface. Initial tests were conducted with a low-PPR hand turned ...
0
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3answers
518 views

RS-422 Signal Confusion

I am interfacing two RS422 devices but failing to do so. I started to monitor my device signals and fell into confusion. Please help me understand a few things. I am attaching snap 01 of my device (...
0
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1answer
451 views

Use RS232 - RS422 Converter with Encoder

Problem I am trying to communicate an incremental encoder (TTL/422) with a PC, however, the PC is modern (correct me if I am wrong, It is a Sabertooth Z77) and doesn't have parallel ports... I found ...
0
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1answer
2k views

how to interface RS-422 to UART on my MCU? [duplicate]

I'm trying to interface RS-422 data to the UART on my MCU (TM4C1294ncpdt) to send it through its ethernet interface. Can anyone help me with how to convert the RS-422 differential signal to be read ...
0
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1answer
290 views

Loopback on LTC2863 RS-422 transceiver not working [closed]

I am using this transceiver chip to communicate between 2 devices. Now, as a loop back test I am connecting the Tx positive to Rx positive and likewise for the negative. Ideally, I should get an echo ...
0
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1answer
253 views

RS232, RS422 Splitter— EDIT fot JTAG [closed]

Is it good to use one UART interface on MCU, RX_UART for receiving data from RS422 receiver and TX_UART for transmitting the same data to the RS232 and RS422 transmitter? I am trying to use UART as "...
0
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1answer
2k views

RS422 charachteristic impedance and its variants

This is regarding the RS422 bus hardware. I have a receiver that has Vih of 1.8V and a max of Vcc(3.3V). Supposing I link a driver and receiver up. The driver,as per the EIA RS422 standards state ...
0
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1answer
1k views

RS232 and RS422 (Isolated and ESD Protected)

I want my RS232 and RS422 to be galvanically isolated and ESD protected. I have two options to implement this requirement. Option 1: MCU-->OPTO-->DRIVER-->ESD PROTECTION Use MAX3232 for RS232 driver ...
0
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1answer
88 views

Questions about RS422 driver

I am using a GPS receiver board which transmits a PPS signal into a TTL <-> RS422 board I need to design. The receiving end (of the RS422 signal) is 15-20 meters away. Here is my design: My ...
0
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2answers
576 views

Connect RS422 interface with Arduino Uno

I have a fishfinder,Lowrance Carbon HSD 7, and I want to connect it with the Arduino Uno to let the fishfinder transmit the Sonar data and GPS data via NMEA0183. According to the maker's site, the ...
0
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2answers
96 views

Help figuring out the interface on this bill validator?

I would like to interface this bill validator to a microcontroller (Arduino Mega). The website says it supports RS232,RS485,Optoisolated RS232 and USB interface. The one I have is currently intefaced ...
0
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1answer
663 views

How to transmit SPI signals through RS422 wire

I'm using several MFRC522 modules which communicate to an arduino with the SPI protocole. The distance between the arduino and the modules will be between 1 and 2 meters. I'm worried about the ...
0
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1answer
189 views

enable pins on RS422 drivers IC

I am using an IC which is an RS422 driver chip. There are 4 drivers in silicon and each can be enabled using a mux kind of enabling system. The screen shot is below - My doubt is - the input comes in ...
0
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1answer
2k views

Wiring RS485/422 to RS232 converter to a given device pins [closed]

I'm trying to establish a full-duplex and then a half duplex communication and need to wire a device output to an RS485/422 to RS232 converter. Here is the device output pins for full and half ...
0
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0answers
18 views

Signal conversion LVDS, RS422 and LVTTL

What are all the parameters required to LVDS to lvttl, RS422 to LVTTL and LVTTL to LVDS and RS422 signal conversion?
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2answers
571 views

rs422/485 maximum terminator resistor value

as i know terminator resistor value is ~120ohm. But i found a circuit that has 10kohm terminator resitor at A and B lines. In circuit transeiver IC is SP3485E. What is the reason for 10k ? That is ...
-3
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1answer
63 views

Rs422 lines passives

I am using an rs422 driver and receiver IC for connecting 2 different boards. Now I have seen many circuits of rs422 which have passives connected in them. Why is that ? And how are they calculated ? ...