PlantScape Vista / HC900 Small Distributed Control System Design principles and objectives are: continuous process to fully meet user requirements and device control * system with high reliability and stability · according to the user's application requirements, support system expansion and upgrades * Strict security system, improve system security ? System can withstand future production control and management requirements of the test * with a powerful graphic display * in the premise of ensuring system security and support data access from inside or outside the enterprise for enterprises to introduce efficient management foundation three-wire and four-wire transmitter with the above advantages are not about to be replaced by two-wire transmitter can be seen from a smattering transmitter chip supply and demand dynamics and the amount of foreign trade , current transducer in the use of power lines to be installed in the field device, and a microcontroller as the core of the monitoring system are located further away from the equipment at the scene of the control room, both generally tens to hundreds of meters away and beyond . Device-site environment is more severe, strong signal will produce a variety of electromagnetic interference pressure transmitters, lightning sensor will produce a strong surge pulse pressure transmitter, a thorny issue in this case, the microcomputer application system encountered is how long-distance transmission of small signals reliably in harsh environments. Output two-wire current transmitter is 4 ~ 20mA pressure transmitter manufacturer, by 250Ω precision resistor into an analog voltage signal 1 ~ 5V or 2-10V The conversion to a digital signal has a variety of methods, if the system is Long-term use in harsh industrial environment is more, therefore we need to consider the safety and reliability of the hardware system works. Input Module system adopts LM231 voltage to frequency conversion device converts the analog voltage signal into a frequency signal absolute pressure transmitter with OCDs TL117 were analog and digital isolation. While the analog signal processing circuits and digital signal processing circuits using two independent power, analog and digital grounds separated from each other, which can improve the security of the system work. Use VFC LM231 device also has some anti-high-frequency interference. In many applications, microprocessor controlled, have to use the transmitter to the microcontroller can not directly measure the signal into a single chip can handle the electrical analog signals, such as current transmitter, pressure transmitter, temperature transmitters, flow rate change delivery and so on. 3051 pressure transmitter, pressure transmitter, Honeywell provided by the Jinan-Technology Co., Ltd. Jinan Huahui Technology Co., Ltd. (www.cnhuahui.com/) strong, credible, in Jinan, Shandong pressure instrumentation industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead China-Technology into the brilliant and you work for a better future!