Switching device and switching method for analog input signal

Abstract

The invention relates to the technical field of frequency converter analog input, and especially relates to a switching apparatus and switching method of analog input signals. The switching apparatus of the analog input signals is connected with a host computer for sending a control instruction and comprises a microcontroller and an analog input unit. According to the invention, the host computer is operated, an operation instruction is sent, the microcontroller receives the instruction from the host computer and sends signals of a voltage input mode or a current input mode, and the analog input unit receives the signals from the microcontroller to carry out switching between voltage input and current input; and the analog input unit then outputs analog signals. Switching of analog voltage and current input does not require manual operation for non-contact intelligent switching, the switching can be arranged through a local keyboard and can also be remotely arranged through a serial port, the intelligentization is high, the operation is convenient, the safety is high, and no damage is caused to components in a switching process.

Description

technical field [0001] The invention relates to the technical field of frequency converter analog input, in particular to a switching device for analog input signals, and in particular to a switching method for analog input signals. Background technique [0002] Analog voltage and current inputs are widely used in the field of frequency converters. In digital control systems, it is often necessary to convert external analog signals (voltage signals or current signals) into signals that can be received by the analog input pins of the CPU (or DSP). For voltage signals, in order to save costs, reduce the size of the device, and make full use of the AD conversion resources of the CPU (or DSP), the same analog input port is often designed to adapt to both user voltage input and user current input. [0003] In the existing technology, the application in different occasions needs to switch between analog voltage and current input, which is realized by using a jumper (or a code swit...

AI Technical Summary

Problems solved by technology

[0003] In the existing technology, the application in different occasions needs to switch between analog voltage and current input, which is realized by using a jumper (or a code switch). By changing the jumper (or The position of the contact of the dial switch) is used to realize the selection of the user's analog input mode (voltage or current). When designing products, it is necessary to expose them to places that are easy for users to touch, and to leave room for the user's fingers or tweezers to operate. This will increase the volume of the digital control device, increase the cost of structural design, and also affect the quality of the product. compact and beautiful

[0006] 1. Poor contact of the jumper cap causes analog input failure;

[0007] 2. The jumper cap falls off and causes an analog input failure;

[0008] 3. It is easy to introduce static electricity by directly plugging and unplugging the jumper cap, which will cause damage to components and make the circuit function invalid;

[0009] 4. It is necessary to disassemble the machine for artificial jumper, which causes inconvenience in installation;

[0010] 5. Traditional analog input has no intelligent protection and alarm function

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