Application of hollysysfoplc in wireless data acquisition system
the santamu operation area of Tarim Oilfield in Xinjiang is an operation area with a radius of hundreds of square kilometers. It is located on the edge of Taklimakan Desert, and the natural environment is very bad. There are 80 oil wells distributed in the whole region. Due to high construction costs and difficult maintenance, the measurement data collection of unattended oil wells can only rely on manual inspection for a long time. However, due to the vast area and poor natural conditions, an inspection often takes more than half a day, and equipment failures cannot be found in time. Therefore, the operation area is determined to transform the Oilfield Metering System
the transformation involves a total of 5 metering stations and 2 valve group stations. The data acquisition and control parts adopt the FOPLC system of Hollysys company. The CPU in the metering station communicates with an intelligent mass flowmeter through RS485 communication module to read 16 metering data in the flowmeter, and the other RS232 communication module is connected to the data transmission radio. The CPU module is responsible for coordinating the work of the two communication modules, And implement the pressure digital display of the three-phase separator in the metering room, the adjustment of the impact tester and the liquid level control. There are 10 well metering valve groups in the valve group station, which are equipped with CPU and several i/o modules. In addition to performing control tasks, CPU can also transmit equipment operation status information to the central station through radio
the central station is a standard PC running focsoft3.0 software of Hollysys. Define a polling tag in focsof3.0. Whenever the system samples the polling tag, focsoft automatically starts operating the radio command and sends a polling command with station number through the radio. 1 # to 7 # RTU stations can receive this instruction, but only the PLC whose own station conforms to the station number in the polling instruction will respond, upload the data stored in the register in advance, and the PC will send a confirmation message to the PLC after receiving the data, indicating the end of this communication, and store the data in the corresponding label. When the central station has data transmission, the operation principle is basically the same. PLC will store the received downlink data in the register for the control program to call. The next polling cycle is set by setting the sampling frequency of the polling label. If a communication fails for some reason, the central station will send an alarm until the next communication is restored
after the application of this system in Tarim Oilfield, the operation is stable. The polling of the central station to seven RTU stations can be completed in a few minutes (the longest distance between the central station and RTU station is 13 kilometers). The data collection is accurate, avoiding all human factors, solving 11 major quality problems, and truly realizing measurement automation. Users believe that the use of this system not only reduces labor intensity, but also greatly improves production efficiency and contributes to the automation of Tarim Oilfield
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