The RS232 interface is a standard for serial communication jointly developed by the American Association of Electronic Industry (EIA) and bell system, modulation regulator manufacturers and computer terminal manufacturers in 1970.
Its full name is "Technical Standard for Serial Binary data exchange interfaces between data terminal devices (DTE) and data communication devices (DCE)", which requires a 25-pin db25 connector, specify the signal content o
Blog directory:1, the UART and RS232, RS485 relations:2, RS232 and RS485 of the difference and pin introduction3. Reference documentsThe text is as followsI. The relationship between UART and RS232 and RS485:Communication problems, and traffic is the same. Serial communication, we can use bus to analogy.Bus operation can be easily divided into two parts: 1, Stati
Serial Port is a very common device communication protocol on the computer.
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Serial Port Pin definition:
9 Cores
Signal Direction from
Abbreviations
Description
1
Modem
CD
Carrier Detection
2
Modem
Rxd
Receive data
3
PC
Txd
Send data
4
PC
DTr
Data Terminal preparation
5
Gnd
Signal Location
6
Learn VC serial port programming, understand the standard of serial protocol is necessary, in fact, the serial port relative to other interfaces (such as USB interface) is very simple.
RS232 Serial port Standard is the United States EIA (Electronic Industry Federation) and Bell and other companies developed a communication protocol. It is suitable for the data transmission rate within the 0~20000BIT/S range of communication.
Differences between TTL level and RS232 level
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When I encountered a problem about the level selection, I forgot the definition of the RS232 level. At that time, I was unable to respond. After I came back, I found out the difference between the two, it may take more than two years for you to forget some common sense that you were familiar with before. This is not a good phenomenon. :-), or copy the differen
Description of RS232/RS485/rs422 Interface Converter The DMUs series converter is a standard RS232/RS485/rs422 converter that completes the electrical conversion between the serial RS232 and RS485/rs422, and can extend the maximum communication distance to 1200 meters (4000 feet ). DMUs adopt the basic three-line system (txd, rxd, Gnd). No software driver is
CAN bus/RS232 interface design
[Date:]
Source: foreign electronic components by Zhao Jie, Liu weijing, Sun Huijia, Li Nan
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1 IntroductionCAN is called "Controller Area Network", that is, Controller LAN, is an international standard, high-price Field Bus, plays an important role in the field of automatic control. CAN is a multi-master serial communication bus with high real-time performance. Therefore, it
This paper describes the design of the controller based on RS232 interface. It uses a single-chip microcomputer to control the interface chip nat914, and uses SCPI statements in the Super Terminal of the serial communication tool that comes with the winelows operating system, the communication and program-controlled operation between the computer and the Kaplan instrument is realized.
More and more measuring instruments provide the general purpose int
A usb to RS232 converter can be used in wince to convert USB to RS232, that is, the usb host of the wince device is connected to the USB end of the USB to RS232 converter, the RS232 end of the USB to RS232 converter can be connected to the
php5| Application Demo
I. Prior knowledge:
What is rs232/rs484 and its application?
QUOTE:RS232 interface is a serial port, computer chassis rear of the 9-core (or 25-core) socket, next to the general has "| o| o| "Sample identification.The general chassis has two, the new chassis may have only one. Laptops may not be available.There are many industrial instruments that use it as a standard communication port. The content and format of the communic
This article for the original article, source code for the original code, such as reprint/copy, please in the page/code location clearly marked the original name, author and website, thank you!
This software is based on NI-VISA/VISA32 (Virtual instrument software Architecture) of the instrument programming, support RS232, USB, GPIB and LAN communication SCPI instrument programming.First, the software is developed using VS2017 (can also be opened
Windows API. NET and communicate with RS232 devices:
Using inheritance, there is also the idea of OO, unlike other can only be counted as a tool class.
The thread is used for receiving, and the inherited classes are automatically received by the thread.
One character is received at a time. Others receive a string at a time. The advantage is that, unlike others, sometimes the results are returned if the receiving is not completed. The di
The power output pin is not defined in the EIA-RS232 standard, so the RS232 interface can not find the power output pin, can only indirectly obtain the power from other RS232 pins. The most direct method is to use pin7 and pin4 pins, which are sufficient to drive mos ic chip devices such as cd4093 and lm324. In addition, you can use the following methods to obtai
What is TTL level, CMOS level, RS232 level? What difference do they have? Generally, the CMOS level has a higher noise tolerance than the TTL level.(i), TTL level standardOutput L: Input L: TTL device output low to less than 0.8V, high level is greater than 2.4V. Input, less than 1.2V is considered to be 0, above 2.0 is considered to be 1. The noise tolerance of the input low level of the TTL level is only (0.8-0)/2=0.4v, and the noise tolerance for t
Now most of the LG TV comes with a serial port (RS232), in fact, through this serial port can completely manipulate the LG TV, and the function than with the remote control powerful. By using the serial port to send instructions, you can do some simple operation of the TV, such as Switch TV, adjust the volume, Exchange channels. You can also perform complex controls such as a tuning table. In addition to the implementation of some remote control can n
What is TTL level, CMOS level, RS232 level? What difference do they have? Generally, the CMOS level has a higher noise tolerance than the TTL level.(i), TTL level standard output L: (ii), CMOS level standard output L: (c), RS232 standard logic 1 level of -3~-15v, logic 0 level of +3~+15v, pay attention to the definition of the level is reversed once.What is the difference between TTL and CMOS level 1. The u
differential transmission mode, also known as balanced transmission, it uses a pair of twisted pair, the first line is defined as a, the other line is defined as B. Normally, the power plane between drive a and drive B is equal to + 2 ~ + 6 V is a logical state with a negative level ranging from-2 V ~ 6 V is another logical state. Another signal C, there is a "enable" side in the RS-485, and in the RS-422 this is available can be used. The enable end is used to control the disconnection and con
Reproduced on: RS232, RS485 Waveform Analysis
I often encounter problems with single-chip serial communication for beginners and do not know how to do it. In fact, the most effective debugging method is to use an oscilloscope to observe the waveforms of the sent and received data. Observe the waveform to determine the following situations:
Whether data is received or sent
Is the Data correct?
Whether the baud rate is correct
1. Serial Data Format
1 logic level
EIA-RS-232C of electrical properties, logic and various signal line functions are defined.
On txd and rxd:
Logic 1 (Mark) =-3v ~ -15 V
Logic 0 (Space) = + 3 ~ + 15 V
On the control line such as RTS, CTS, DSR, DTR, and DCD:
Effective Signal (on, positive voltage) = + 3v ~ + 15 V
Invalid signal (disconnected, off, negative voltage) =-3v ~ -15 V
2. Pin Definition
Pin definition symbol
1 Carrier Detection DCD Pin 1 received Line Signal Detector (data carrier dete
The difference between RS485 and RS232:
RS232 is full-duplex communication, when the data is sent, you can also receive data, but you may feel unclear, such as in the application, you go to the operation of the serial port writing, you do not feel able to read the serial port data, because the CPU is a single core, CPU only one brain, Only one person is working, so you will feel you to operate the seria
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