Current loop isolation, transmission and integration module and multi-channel current transmitting system thereof

Abstract

The invention discloses a current loop isolation, transmission and integration module. A digital power supply, an analog power supply, a micro-programmed control unit (MCU) and an external printed circuit board (PBC) are connected on the outer side of the current loop isolation, transmission and integration module which is used for outputting current analog signals of 0 to 20 milliamperes and 4 to 20 milliamperes after two channels of digital signals are transformed. The current loop isolation, transmission and integration module comprises a digital to analog converter (DAC), a double channel signal conditioning circuit, a double channel voltage-current conversion circuit, a digital isolator, a digital power interface, an analog power interface, two current loop output interfaces and a serial peripheral interface (SPI) bus interface. According to the current loop isolation, transmission and integration module, the digital to analog converter (DAC), the double channel signal conditioning circuit, the double channel voltage-current switching circuit and the digital isolator are packed in a mini-type package module, so that influences caused by whole circuit layout and wiring on the current loop isolation, transmission and integration module are effectively avoided, and the area of the PBC are effectively saved.

Description

technical field [0001] The present invention relates to a current loop isolation and transmission integrated module and its multi-channel current transmission system, in particular to a current loop isolation and transmission integrated module for converting digital signals to analog signals and its multi-channel current transmission system. The current loop isolation and transmission integrated module and its multi-channel current transmission system can be applied to wind power generating sets. Background technique [0002] The 0~20 / 4~20 mA current loop is a common way to transmit analog signals in industrial applications. Compared with 0~10V / ±10V, it has the characteristics of longer transmission distance and better anti-interference. Since most industrial-grade instruments are now smart instruments, and they are all digital signals, converting digital signals into 0~20 / 4~20mA current analog signals usually requires the use of digital-to-analog converters DAC, signal cond...

AI Technical Summary

Problems solved by technology

Since most industrial-grade instruments are now smart instruments, and they are all digital signals, converting digital signals into 0~20 / 4~20mA current analog signals usually requires the use of digital-to-analog converters DAC, signal conditioning circuits, and voltage- Signal conversion and transmission can only be realized by the cooperation of the current conversion circuit and the like; in addition, in actual design applications, the digital-to-analog converter DAC, signal conditioning circuit, voltage-current conversion circuit, etc. are often integrated into a PCB board, and One digital signal needs to cooperate with the design of corresponding digital-to-analog converter DAC, signal conditioning circuit, voltage-current conversion circuit and other circuits on the PCB. If there are multiple digital signals, it is necessary to design multiple circuits on the PCB. The corresponding digital-to-analog converter DAC, signal conditioning circuit, voltage-current conversion circuit and other circuits can complete the conversion of multiple signals; at the same time, due to the withstand voltage requirements of industrial-grade instruments, the circuit design needs to isolate digital signals from external signals. Phase isolation, the addition of isolation circuits will further increase the PCB area. For devices with different uses and shapes, the layout and wiring of the entire circuit will be changed due to board type restrictions, resulting in different withstand voltage strengths, accuracy errors, electromagnetic interference

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