Shift series connection type digital display meter

Abstract

The invention relates to a shift series connection type digital display meter which is suitable for controllers, such as a PLC, a computer, an SCM, and the like. The shift series connection type digital display meter mainly comprises a 74HC595 serial shift chip, an LED digital pipe, a digital pipe current limit resistor, an input and output signal light isolation chip, an input signal clamp resistor, an output light isolation limit resistor, an input and output socket, a power supply terminal strip, a digital display meter shell, and the like. The digital display meter is in a series connection way and has the characteristics of simple manufacture, low cost, high reliability, convenient installation and use, and the like. The data display of a plurality of digital display meters can be realized just by three signal lines, and both the input and the output of the digital display meter have the optoelectronic isolation function and have the signal drive function simultaneously. In addition, the digital display meter has static display and the data latching function; and even if an external control signal disappears, the digital display meter can still display the previous data normally.

Description

technical field [0001] The invention relates to an electronic device, in particular to a displacement series digital display meter suitable for multiple data display using PLC etc. as a controller. Background technique [0002] PLC is one of the most commonly used control devices in control systems. It is widely used in process control in various fields due to its highly reliable performance, convenient and flexible development, and high cost performance. Although there is a PLC man-machine interface available, it is expensive. When developing a small-scale PLC control system, it takes up a large proportion of investment. Sometimes only a few key data need to be displayed, and sometimes LEDs are needed for data display, so that it can be far away. Watch from a distance. At present, there are two main types of LED digital display products that can be directly displayed by PLC on the market: one is to install a D / A conversion module to output standard voltage or current signa...

AI Technical Summary

Problems solved by technology

The latter method is simple in structure, but if dynamic display is performed, at least 12 output points of PLC are required to display a four-digit data; if static display is performed, 32 output points of PLC are required to display a four-digit data, and the more displayed data More output points are needed, and there is also a situation of excessive investment

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