Fundamentals of RS-422: Serial Data Standard (Basics)

 INTRODUCTION TO RS-422: Serial Data Standard

RS232 to RS485 / RS422 Serial Communication Data Converter Adapter Mini-Size

What is the meaning of Rs-422?

Recommended Standard 422

Recommended Standard 422 (ANSI/EIA standard for serial data transmission)

In 1975, the first version of the RS-422 was released. RS422 was created to allow for faster data transmission over serial data lines than RS232 does. RS-422 is an upgraded design of RS-232 that uses twisted pair cable and signal balancing to allow up to 10 transceivers while only supporting a single transmitter. Longer distances can also be compensated. Because of the differential signal and other methods used, RS422 has even faster data rates than RS232.

At distances of up to 50 feet, RS422 can deliver data rates of up to 10 Mbps (15.24 metres). However, RS422 can transmit data over distances of 4000 feet (1220 metres) using reduced data rates: the limit is 100 kbps.

Data can be transmitted using balanced or differential signalling, with unidirectional/non-reversible, terminated or non-terminated transmission lines, point to point, or multi-drop transmission lines. RS-422/V.11, unlike EIA-485, allows only multiple receivers, not multiple drivers.

RS422 9 Pin connector (DB-9)

The main features of the three protocols are summarised in the table below:

USB to RS422 /RS485 Serial Interface

RS422 RS485 Serial Port Converter Adapter Cable with FTDI Chip Supports Windows 10, 8, 7, XP and Mac (1.2m)

RS-232 STANDARDS, PIN DETAILS, BAUD RATE AND CABLE LENGTH

 

RS-232 INTERFACE

The Electronic Industries Association (EIA) represents serial data exchange joining two devices as the RS-232 interface. The EIA created it to standardize the link of computers to telephone connection modems. The specification allows for up to 20 signals to be identified, but the user has full control. Send data, receive data, and the signal ground is all that is needed. The remaining lines can be permanently turned on or off. The signal transmission requiring two voltages of opposite polarity ranging from 5 to 25 volts.

                                                       

Fig-01 Direct-to-computer RS-232 Interface

Communication Standards

According to industry standards, an asynchronous word consists of a start bit, seven or eight data bits, parity bit (optional), and one or two stop bits. The computer determines the baud rate at which the word is sent. The baud rate, which can range from 0 to 7, is normally 150 times an integer power of two (150, 300, 600,...., 19,200 ). Many system-unique rates are used below 150 baud. The basic RS-232-C connector has 25 pins, with 21 of them being used by the standard. When a computer node is connected straight away to a computer, many of the modem signals are not required, and Fig-01 shows how some of the "spare" pins can be linked if they are not required. Fig-01 also shows the pin numbering used with the original DB-25 connector and the pin numbering now widely used for the DB-9 (D type 9 Pin connector) connector used in most modern computers.

 

Fig-02 RS-232 Serial Port

Fig-03 Serial Port Pin and Signal Assignments

Maximum Baud Rate and Cable Length

One of the most hotly debated topics in the RS232 world is cable length. The response is clear in the standard: the maximum cable length is 50 feet, or the cable length equal to 2500 pF capacitance. The latter rule is often overlooked. This ensures that using a low capacitance cable helps you to span longer distances without exceeding the standard's limitations. The maximum wire length allowed is ~147 feet when using UTP CAT-5 cable.

The standard sets a cable length that provides for the fastest possible transmission. When the speed is reduced by a factor of two or four, the overall length increases dramatically.

Years ago, Texas Instruments conducted several practical tests at various baud rates to determine the maximum cable lengths that could be used. Remember that the RS232 standard was created with a data rate of 20 kbps. By reducing the maximum transmission speed, the possible cable length increased by 10!

Fig-04 RS 232 Data Rate and Cable Length

1. USB to RS232 Adapter with PL2303 Chipset, CableCreation 6.6 ft USB 2.0 Male to RS232 Female DB9 Serial Converter Cable for Cashier Register, Modem, Scanner, Digital Cameras, CNC,Black

2. CableCreation USB to RS232 Adapter (FTDI Chipset), CableCreation 3 Feet RS-232 Male DB9 Serial Converter Cable for Windows 10, 8.1, 8,7, Vista, XP, 2000, Linux, Mac OS X 10.6 and Above,1M / Black

3. Moxa UPort 1110 1 Port RS232 to USB Converter 2.0 Adapter

4. DTECH USB to RS422 RS485 Serial Port Converter Adapter Cable with FTDI Chip Supports Windows 10, 8, 7, XP and Mac (1.2m)

 

5. RS232 to RS485 / RS422 Serial Communication Data Converter Adapter Mini-Size

 

 

Arduino UNO for Middle school, High school, and University Students

ARDUINO UNO

 

The Arduino UNO is the perfect board for beginners who want to learn about electronics and programming. The UNO is the most stable board you can start with if this is your first time tinkering with the platform. The Arduino UNO is the most famous and well-documented board in the Arduino family.

FUTURE ENGINEERS, SCIENTISTS AND ARTISTS SHOULD BE EMPOWERED

Arduino Education develops the next wave of STEAM services to support students as they progress through middle school, high school, and university.

Arduino Uno R3

The Arduino Uno R3 is a microcontroller board based on the ATmega328P. It comes with everything you need to support the microcontroller; all you have to do is plug it into a PC via USB and power it up with an AC-DC adapter or a battery to get started. Uno is an Italian word that means "one" and was chosen to commemorate the release of Arduino's IDE 1.0 programme.

Arduino Uno R3 Specifications

The Arduino Uno R3 board includes the following specifications.

• Microcontroller ATmega328P 
• Input voltage span from 7V to 12V
• The operating voltage of the Arduino is 5V
• Digital input and output pins 
• Analog Input pins 
• DC Current used for 3.3V Pin is 50 mA
• DC Current for each I/O Pin is 20 mA
• SRAM is 2 KB
• ROM Memory is 32 KB 
• boot loader memory 0.5 KB 
• EEPROM is 1 KB
• In-Built LED
• The clock speed is 16 MHz
• Arduino board weight is ~25 g
• Dimensions of the Board are 68.6 mm X 53.4 mm

Arduino UNO Pinout Diagram

Digita Channel

Pin Details

Description

Remarks

D0

Pin 0

Serial UART (Receive pin)

D1

Pin 1

Serial UART(Transmit pin)

D2

Pin 2

Interrupt Channel 0

D3

Pin 3

Interrupt Channel 1

D4

Pin 4

D5

Pin 5

D6

Pin 6

D7

Pin 7

D8

Pin 8

D9

Pin 9

D10

Pin 10

Slave Pin

D11

Pin 11

MOSI

SPI Master Out-Slave In

D12

Pin 12

MISO

SPI Master In-Slave Out

D13

Pin 13

SCK

SPI Clock

Analog Channel 

Pin Details

Description

Remarks

A0

Pin 0

A1

Pin 1

A2

Pin 2

A3

Pin 3

A4

Pin 4

-

A5

Pin 5

-

Power Pins

Pin Details                                            Remarks

GND                                                        Ground

RESET                                                     Reset

5V

5V Source

3.3V

3.3V Source

1. RoboCraze UNO R3 SMD Board compatible with Arduino | Development Board with USB cable

2. Arduino UNO R3 Original | Genuine Arduino UNO Board with DIP ATmega328P

3. UNO Robotics Kit compatible with Arduino IDE

 

4. Multipurpose Starter Kit for Arduino IDE- NODEMCU (IOT) - Robotics For Beginners 

5. Quad Store LEVEL-2 kit with RFID and bluetooth compatible with Arduino IDE and Uno R3

 

 

Python variable

 

Hi...

Let's go through some factors about Python Variables in this blog

1. What variables are?

2. Create our first variables in Python 

3. Learn about variable " type() " 

So let's get started

Well to understand easily we can consider Variable as a box where we can store data. Data can be of any type such as text, images, video, audios, etc.

Now, the variable contains two things :
1. Name
2. Value

A) Assign " Integer type " value in the variable name Number.
here "Number" is the variable name and the value assigned in it is "10" 👇.

Whenever we type the Number, it will show the contained value here "10"☝.

B). Now, We can assign " String type " data on the same variable
Number = "JK"

C). Now, We can assign "Float type " data on the same variable

let's check the type of value stored in our variable "Number"

How??

Yea!... you got it right it's now time to use  " type( ) " keyword :👇👇

Important Points :

#1. Python variables are case sensitive means variable name "Number" is different from "number".

#2. Python variables are Dynamically typed variable means there is no need to define a variable type like int, float, char, etc before assigning value. But in another languages like C, C++, Java, etc we need to define data type before assigning any value in the variables.  C, C++, Java are the statically typed() whereas python is Dynamically typed.

#3. The last value stored is retained in the variable.

Review :

1. Variables are like boxes that store data.

2. Variables can be defined as -     variable = value

3. In Python, Variable type can be changed Dynamically.

4. Use the type() variable to get variable type.

Great, enjoy practising till next blog comes☺...

Python Boolean Operations

Python Boolean Operations: and, or, not 

Boolean operators such and, or, and not are also called logical operators.

" and " and " or "operators requires two variables whereas " not " operators need only one variable. 

1. "and " operator test example :

It is interesting to know that "and" is a short-circuit operator, it checks both the arguments if both the operands are true or both are false then it returns true. Whereas if any one of the operands is true and other operands are false then it returns false.

# boolean "and" operator test program

x= 5
y=10
print(x);
print(y);
if (x>3 and y>1):
   print("true")
else:
   print("false") 

2. "or " operator test example :

Like "and" the "or" is also short-circuit operator, it also checks both the argument if any operand is true it returns true. Whereas, if all operands are false then it returns false.

# boolean "or" operator test program

x= 5
y=10
print(x);
print(y);
if (x>10 or y>12):
   print("true")
else:
   print("false") 

3. " not " operator test example :

This operator is also called inverter operator which actually clarifies it's nature or function. It just provides the inverted output. Means if an operand is true then it returns false and vice-versa. It requires only one operand.

# boolean "not" operator test program

x= 5
y=10
print(x);
print(y);
if not (x > 10) :
   print("true")
else:
   print("flase")