A/D D/A converter application in the remote monitoring

Aug. 20, 2010 - PRLog -- Abstract:This article describes the using of analog output module ISODA remote device control applications. PLC or DCS system, the AO module analog output current or voltage signal directly to control the implementation of the remote device, often because of signal attenuation, distortion caused by long-distance transmission, and sometimes because of signal errors caused by other external signal interference, the entire system does not work properly. ISODA remote analog signal output module use the RS-485 differential digital signal transmission and it can effectively improve the system anti-jamming capability, using RS-485 bus communication and address can be setting, in some cases can also reduce cabling, lower costs and improve equipment control system reliability.
Key words:　RemoteAD DA conversion　 Analog signal output　　Remote IO　
RS-485/RS-232 Data Communication　
1. signal A / D (Analog to Digital) converter and remote transmission technology
  ISO 4021 signal A / D (Analog to Digital) converter can be realized between the sensor and the host signal acquisition, to detect an analog signal or control a remote device. Through software configuration, can be used for a variety of sensor types, including: analog input, analog output, and digital signal input / output (I / O). RS-232/485 bus widely used in industrial automation control systems ,4-20mA / 0-5V signal measurement, monitoring and control, small-signal measurement, and industrial on-site signal isolation and long-term transport and so on.


 ISO 4021 signal A / D (Analog to Digital) converter, including power supply isolation, signal isolation, linearization, A / D conversion and RS-485 serial communication. Each serial port of the maximum 256 ISO 4021 series of modules, means of communication using ASCII code or MODBUS RTU communication protocol communication protocol, its instruction set compatible with the ADAM modules, the baud rate is set by the code, with other manufacturers control module hang on the same RS-485 bus, to facilitate computer programming.

ISO 4021 signal A / D (Analog to Digital) converter is a microcontroller-based intelligent monitoring and control systems, all the user to set the calibration value, address, baud rate, data format, checksum status and other configuration information is stored In the non-volatile memory EEPROM inside. ISO 4021 series of products according to industry standard design, manufacture, signal input / output between the isolation can withstand 3000VDC isolation voltage, anti-jamming ability, and high reliability. Operating temperature range - 45 ℃ ~ +85 ℃.

1>analog signal input
24-bit capture accuracy, the products all the signal input range of the former factory has been fully calibrated. In use, the user can easily calibrate their own programming. A specific current or voltage input range See product selection, measuring two-way signal 2 input selection must be the same.
2>communication protocol
Communication interface: a way a standard RS-485 communication interface or a way a standard RS-232 communication interface, order selection, when indicated.
Communication protocols: support two protocols, command sets the characters defined protocol and MODBUS RTU communication protocol. Can be programmed using the kind of communication protocol can be achieved with a variety of brands of PLC, RTU or computer monitoring system for network communication.
Data format: 10-bit. 1 start bit, 8 data bits, 1 stop bit.
Mailing address (0 ~ 255) and the baud rate (300,600,1200,2400,4800,9600,19200,38400 bps) can be set up; communication network of the most long-distance up to 1,200 meters, through the twisted-pair shielded cable.
Communication interface of high anti-jamming design, ± 15KV ESD protection, communications, response time is less than 100mS.

3>anti-jamming
According to need to set checksum. Module internal transient suppression diodes, can effectively inhibit a variety of surge pulse protection module, the internal digital filter can also be a very good suppression of interference from the grid frequency.

2.signal D / A (digital switch to analog) conversion and restore monitoring technology

ISO DAO signal D / A (digital switch to analog) converter allows the host RS-485/232 interface, digital signal isolation converted into standard analog signal, to control the remote device. RS-232/RS-485 bus widely used in industrial automation control system 0-20mA/4-20mA/0-5V/0-10V standards such as analog signals to restore the output to control the implementation of industrial field devices, control equipment, and display instruments and so on.
ISO DAO signal D / A (digital switch to analog) converter, including power supply isolation, signal isolation, linearization, D / A conversion and RS-485 serial communication. Each serial port of the maximum 256 ISODA series of modules, means of communication using ASCII code or MODBUS RTU communication protocol communication protocol, its instruction set is compatible with most similar module, the baud rate is set by the code, with other manufacturers control module linked In the same RS-485 bus, to facilitate computer programming.
 ISO DAO signal D / A (digital switch to analog) converter is a microcontroller-based intelligent monitoring and control systems, all the user to set the calibration value, address, baud rate, data format, checksum status and other configuration information is stored In the non-volatile memory EEPROM.
ISO DAO signal D / A (digital switch to analog) converter according to industry standard design, manufacture, signal output / communication interface between the isolation, can withstand 3000VDC isolation voltage, anti-interference ability, high reliability. Operating temperature range - 45 ℃ ~ +80 ℃.

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Founded in 2002, Shenzhen Sunyuan Technology Co., Ltd. has been dedicating to design and produce DC-DC Converter, Electronic Transmitters ,Speed Transmitters and Analogue To Digital Converters. These modules are available in both PCB and DIN rail mounted.