Three-wire and four-wire transmitter with the above advantages are not about to be replaced by two-wire transmitter from the transmitter chip supply and demand dynamics and the amount of foreign trade can be seen a smattering of pressure STG74L, current transducer in use To install field devices in the power line, and a microcontroller as the core of the monitoring system are located further away from the equipment at the scene of the control room on-line STG74L, 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, lightning sensor will produce a strong surge pulse STG74L, in this case, a thorny issue microcomputer application system encountered is how far in harsh environments from the reliable transmission of small signals. Two-wire transmitter output current is 4 ~ 20mA, through precision resistor 250Ω 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 in the environment is more severe Long-term use of the industrial site, and therefore 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 photoelectric coupled device TL117 perform 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 STG74L transmitter, 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. Experion Vista / HC900 Hybrid process automation control systems PlantScape Vista / HC900 is Honeywell distributed control system's latest applications and equipment for small and medium open process control system integrated control. The system consists of high-performance engineering station refined design of advanced integrated controller HC900 and independent of or with open Ethernet interconnect / operator station form a complete and can really meet all types from simple to complex industries Control applications require distributed control system. The configuration tool process data acquisition, mixed analog and digital process control and batch processing, and other applications based on the timing control and the use of functional modular HC Designer, PlantScape Vista / HC900 Distributed Control System provides users with a widely used biopharmaceuticals The distillation column reactor, steam turbine power plant boiler, furnace smelting furnace metallurgy, chemical industry and a variety of equipment and food machinery and other industrial furnace plant and equipment and other various control level of high performance control systems. Pressure STG74L | Honeywell (certified) | STG74L provided by the Jinan-Technology Limited. Jinan Huahui Technology Co., Ltd. (www.cnhuahui.com/) Shandong Jinan, pressure meters leaders, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. - Technology leader in China with the staff warmly welcome all inquiries negotiations to create Hua Hui Technology better future.