rs485 pinout

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

Wince debugging RS485 serial port sense (Serial library implementation of the source program in: http://download.csdn.net/detail/dijkstar/4072407 download, 2012-02-16 add; use Microsoft serial control MSComm Implementation of the source program in: http://download.csdn.net/detail/dijkstar/4199667download, 2012-04-04add) this article continues with "RS485 half duplex software programming implementation. As m

First, RS485 basic knowledgeRS-485 interface chip has been widely used in industrial control, instrumentation, instrumentation, multimedia networks, electromechanical integration products and many other fields. There are also more and more types of chips available for RS-485 interfaces. How to find the most suitable chip in a wide range of interface chips is a problem in front of every user. RS-485 interface in different use situations, the requiremen

I haven't updated my blog for a long time. Don't think I'm too lazy because I started school, but my study in the New Tang Dynasty is not over. I haven't written a blog for such a long time because I encountered a tangle problem during my learning process. This problem has been nearly three weeks since January 1, September 1, that is, RS485 communication, I would like to write down my own mistakes to avoid detours when I see the article. If you want t

]=(byte) (Temp >>8) ; crc[1]=(byte) (Temp 0x00FF); returntemp;}voidSendData (byteData[],intcount) { bytecrc[2]; CALCULATECRC (DATA,COUNT,CRC); for(intI=0; i) {myserial.write (data[i]); } myserial.write (crc[0]); Myserial.write (crc[1]);}//=================================================//==============byte to Hex string===============String Tohex (byteBs[],intcount) {String bundle=""; for(intI=0; i) {Bundle+ = (String) (hextable[bs[i]/ -]) + (String) (Hextable[bs[i]% -]); } returnbundle

-pin serial port function is shown in table 1.* Db25 (25-pin socket), 3. The 25-pin serial port function is shown in table 2.* Another type of plug-in port is RJ45. For example, The SNI high mss1600 and mss700 Video Server encoding and decoding board control ports used by Hubei TV station are all serial ports. The plug-in ports are RJ45 and the serial port of the broadcasting controller is DB9, therefore, we need to use a conversion cable. Pin Definition 4 of the conversion cable.RS485 half-dupl

common noise and can not suppress common mode interference and other problems, so it is generally used for communications within 20 m. 2. RS-485 RS-485 bus, when the communication distance is dozens of meters to kilometers, widely used RS-485Serial Bus. The RS-485 adopts balanced transmission and differential reception, so it has the ability to suppress common mode interference. In addition, the bus transceiver is highly sensitive and can detect voltage as low as 200mV. Therefore, the transmi

There may be many reasons for communication failures in RS485 networks. You can consider the following ideas: 1. Incorrect communication cable connection (including poor contact) Physical failure is the simplest problem, but it is also the easiest place to make mistakes. Correct cable connection is the basis for communication. In actual application, ensure that the wiring is correct. In many cases, the pipe and foot codes on the connector are small

Raspberry Pi native Serial port default for console output, if you want to use in your own program need to shut down the system to occupy this serial port. The method is configured for Rasp-config, or directly modifies the/boot/cmdline.txt #dwc_otg. lpm_enable=0 console=tty1 console=serial0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator= Deadline Fsck.repair=yes Rootwai Dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes Rootwai After the

I. Several Concepts about 485 bus:1. The communication distance of the 485 bus can reach 1200 meters.According to the 485 bus structure theory, the transmission distance of the 485 bus can reach 1200 meters under the ideal environment. The condition

1 reviewsMAX3483, MAX3485, MAX3486, MAX3488, MAX3490, and MAX3491 are 3.3V, low power transceivers for RS-485 and RS-422 Communications, with one driver and one receiver in each device. The MAX3483 and MAX3488 have a slew-limiting driver that

1. Sending and receiving controllers: During r25 welding, when R22 is suspended, the single chip microcomputer pin is separately controlled; When r25 is suspended, R22 is controlled by the sending pin during welding;   2. When the upper and

: R65 is disconnected. r66 is connected to the 3.3v voltage. rx422t is the sending end. It is used with 485tx and rx422r and 485rx. The circuit itself is not difficult. Maybe you have found out what I want to say. The De and Ro terminals are

P13 eth0 (Electrical port-compatible with optical ports, if using optical ports, please remove U31 and P13)P12 eth1P9/DEV/TTYS3 Debug PortP10-1/dev/ttys2 rs485+P10-2/dev/ttys2 rs485-P10-3 Rs485-gndP10-4/dev/ttys2 rs485+P10-5/dev/ttys2 rs485-P10-6

I. RS485 interface circuit diagram inside the S7-200PLC: see the attachment for circuit diagram In the figure, R1 and R2 are common resistance with a resistance of 10 euro. Their function is to prevent the generation of an over-current burned-out chip when the RS485 signal D + and D-short circuit are used. Z1 and Z2 are the 6 V clamping voltage, zonea diode with a maximum current of 10A. The 24 V power supp

, it consists of analog signal conditioning circuit, A/D conversion circuit, display circuit and 485 communication circuit. The signal must be processed before it enters the/D converter. analog signal processing is one of the important factors affecting the system performance. signal quality should be taken into consideration during design to improve the signal-to-noise ratio and minimize distortion. In the design, the potentiometer is used in the conditioning circuit for fine-tuning, and the vo

/11. 0592/1000000 s Single-Chip Microcomputer machine cycle T3 = 12 * t2 T1/T3 = 96 That is, for the serial port of 9600bps, the single-chip microcomputer samples it at a rate of 96 times. If the MCU crystal oscillator is used incorrectly, the serial port will receive an error code. --------------------------------- RS485 and rs422 RS485 bus, when the communication distance is dozens of meters

Tags: control val error wrapper function lock mode test tool return1. Introduction Modbus is an important protocol in the industrial field, the physical layer has a common RS485 twisted pair and TCP, so it is often said that Modbus 485 development and Modbus TCP development. The former is the serial communication, relatively simple. The latter relates to network protocols, which have several levels of complexity. However, if there is a stable TCP comm

PLC (Programmable Controller) is widely used in the industrial control field, and its ease of use is self-evident for slightly knowledgeable people. However, the data communication and setting of PLC are both implemented through RS485 wired mode. For general users, the PLC equipment is designed and integrated in the transformation or improvement project, in this case, it is very troublesome to re-deploy the communication lines. It is very painful for

Source: Design of communication protocol in embedded systemThat's wonderful!Companies do projects, embedded systems are large and small, everywhere. Because all are in a system, so all need communication, since the communication is related to the protocol problem.Talking about the agreement, many engineers feel that the design of the protocol is relatively simple, mainly the design of the message. Most of the time, the protocol scenario is simple and has no complex interaction. There is no big p