Serial communication port, two computers can be connected with a cable to communicate, but also can be connected to some serial communication port expansion equipment. In order to realize serial communication, PCS are usually equipped with two serial interfaces that meet the RS-232C standard and use a serial controller composed of universal asynchronous receiver\/transmitter control chip UART to process the transmission and receiving of serial data. The serial interface on PCS usually uses 25-core or 9-core DB-25 or DB-9 connectors. It is mainly used to connect the MODEM device to work, so the RS-232C standard stipulates many MODEM special interface leads. At present, the more commonly used RS232 serial ports are 9-pin D-shaped serial port [DB9] and 25-pin D-shaped serial port [DB25], and the maximum communication distance is [15m]. When the distance between two devices is relatively close, the 232 serial ports of the two devices can be directly connected by 232 cable. If the distance is far away, the connection can be connected through a MODEM. RS232 interface -- ● Use \"negative logic\" -- the output end is represented by +5V ~ +15V [logic 0], and -5V ~ -15V is represented by [logic 1]. ● \"Single-ended drive\" is adopted - the drive level is output through the data sender [TD] and the signal ground GND is used as a reference point. ● Adopt \"single-ended reception\" - input the receiving level through the data receiving end [RD], and use the signal ground GND as a reference point. RS232 three-wire system - can achieve [point-to-point two-way communication], need 3 communication lines, the data sending end [TD] of the main side and the data receiving end [RD] of the slave side are connected, the data receiving end [RD] of the main side and the data sending end [TD] of the slave side are connected, the signal ground [GND] of the two sides are directly connected. RS232 use precautions - RS232 serial port can not be directly connected to RS485 serial port - because their electrical standards are not the same; There are various serial port converters available on the market, which must be connected through a converter. In addition, do not plug or dial the serial port with power on, at least one end is powered off when plugging, otherwise it is easy to damage the serial port.
To connect to the 232 port on the back of your computer, you need a serial cable (also known as an RS-232 serial cable) and plug it into the serial port jack of your computer.
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Here are some basic steps:
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Make sure your computer has an RS-232 serial port. Most modern computers no longer come with this interface, so you may need to purchase an RS-232 to USB adapter.
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Find the RS-232 port on the back of the computer, which is usually a DB-9 or DB-25 port.
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Take out the serial cable, one end should be a DB-9 or DB-25 connector, depending on the type of interface your computer is using.
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Connect the other end of the serial cable to the serial port of the device you want to connect to.
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Turn on your computer and boot the device, then open the corresponding serial port communication program on your computer, configure the serial port parameters (such as baud rate, data bits, check bits, etc.), and then start communicating with the device.
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Please note that the specific connection methods and configuration steps may vary depending on the device type and operating system. Therefore, please refer to the instruction manual of your device and computer for more detailed instructions.
Connecting to the RS232 interface on the back of the computer usually requires the use of an interface converter, because modern computers do not usually have an RS232 serial interface, and devices using this interface are still very common. Here are the steps to connect the RS232 port on the back of your computer:
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1. Determine the type of RS232 interface that the device you want to connect needs to use, which is generally divided into DB9 and DB25. The RS232 interface on a computer is usually a DB9 interface, so if the device uses a DB25 interface, you need to use a DB9 to DB25 interface converter.
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2. Select a proper serial cable, usually a DB9 or DB25 serial cable.
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3. Connect one end of the serial cable to the RS232 port on the PC and the other end to the RS232 port on the device to be connected. If you use an interface converter, you need to plug it into a USB or other type of interface on your computer.
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4. Open the terminal software or other application that can use the serial interface on your computer, and you can start using the connected device.
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It should be noted that when connecting the RS232 interface at the back of the computer, be sure to pay attention to whether the interface to connect the cable is DB9 or DB25, and choose the correct converter model when using the converter. In addition, you also need to pay attention to the signal level, baud rate and other parameters of the serial port to ensure that the connected device can work properly.